Patent Application
20230352774
The present invention relates to the field of batteries and energy cells. Embodiments of the invention relate to a pouch cell battery assembly comprising a pouch cell battery cell and an electronic device, wherein the electronic device is configured to determine at least one property of the pouch cell battery; and to battery packs comprising a plurality of the aforementioned pouch cell battery assemblies.
Conventional battery packs such as those used in, for example, electric vehicles and modern electronic devices, comprise a plurality of electrically coupled battery cells. The battery pack may comprise a measuring device arranged to measure a performance characteristic of the battery pack, such as the voltage or current output by the battery pack. Faulty and non-ideal operation of the battery pack may then be inferred from voltage and/or current measurements. Identification of the precise source of a fault within the battery pack, or the cause of a divergence from ideal operation, is often not possible because the monitored performance characteristics may not provide sufficient detail about the performance of individual cells within the battery pack. As a result, when faulty or non-ideal operation is detected, the entire battery pack is replaced. For similar reasons, catastrophic failure of an individual cell within the battery pack may go undetected, and can result in significant safety hazards, including fire.
Conventional battery packs often comprise a plurality of pouch cell batteries. Each pouch cell battery comprises an anode, a cathode, and an electrolyte through which ions move. In rechargeable cells, the anode serves as the negative electrode. Multiple cells may be stacked in series and/or parallel depending upon the current/voltage requirements to form a battery pack. For portable devices such as laptops or smart phones, low profile batteries are required which may use an expandable pouch, which is sealed along edge regions of the pouch rim, with contact terminals protruding out through a sealed end region, and available for connection to the device which the battery will power. The pouch cell battery may comprise at least one electrochemical arrangement. Each electrochemical arrangement may be contained within the pouch cell enclosure, and more specifically the sealed expandable enclosure. In operation, when current is drawn from the pouch battery cell, the expandable enclosure may be subject to thermal expansion.
A pouch cell battery has an internal multi-laminate construction of a plurality of planar electrodes, separated by microporous polypropylene or polyethylene separator layers, sandwiched between copper and aluminum electrode plates. Each combination represents a single electrical power cell. A pouch cell battery may comprise a plurality of electrical power cells. Each power cell end may include two internal flexible contact tongues stacked and welded together with neighboring flexible contact tongues. The anode stack is then welded to a single flat external anode contact terminal and the cathode stack is welded to a counterpart single flat external cathode contact terminal. The electrodes may be made of any one or more of: graphite, lithium titanate, silicon, lithium metal oxide, or combinations thereof.
In use, certain parameters may be monitored, including: temperature, voltage, and current, to ensure that the battery pack is operating within a safe operating range. Thermal management helps maintain a safe operating temperature.
It is desirable that battery packs have high energy density, measured both in terms of joules per kilogram (gravimetric energy density) and joules per liter (volumetric energy density).
This requires that the battery comprises maximum energy storing materials, and as little extraneous material as possible, in consideration of the power delivery, thermal and safety requirements of the battery. Thus, there is a desire to limit the amount of cabling, wiring, connectors, sensors, thermal and structural support materials present in the battery pack as possible. Extraneous materials occupy volume and add weight, reducing the overall battery energy density.
It is an object of at least some embodiments of the present invention to address one or more shortcomings of the prior art battery packs, in particular, battery packs comprising pouch cell batteries.
In accordance with an aspect of the present disclosure, a pouch cell battery assembly is provided comprising a pouch cell battery, and an electronic device configured to determine at least one physical characteristic of the pouch cell battery. The pouch cell battery comprises an expandable enclosure accommodating an anode stack, a cathode stack, and a separator disposed between anode and cathode stacks. The pouch cell battery comprises first and second contact terminals, the first contact terminal being electrically coupled to the anode stack and the second contact terminal being electrically coupled to the cathode stack. The electronic device is at least partly affixed to the expandable enclosure, and is electrically coupled to the first and second contact terminals. The electronic device is configured to determine at least one physical characteristic of the pouch cell battery.
Electrically coupling the electronic device to the first and second contact terminals enables the electronic device to be powered by the pouch cell battery, thus obviating the need for any further power source. The electronic device may be powered even when the pouch cell battery is not supplying energy to a load. Electrically coupling the electronic device directly to the pouch cell battery enables determining a physical characteristic of the pouch cell battery. This is particularly useful for monitoring the performance and health of individual pouch cells in a battery pack. In this way, embodiments may identify degraded performance and failure of individual cells within the battery pack, enabling the individual affected cells to be serviced and/or replaced, without requiring replacement of the entire battery pack. In accordance with some embodiments, the electronic device may be directly connected to the first and second contact terminals via one or more conductors, such as wires. In some embodiments alternative coupling methods may be used, such as magnetic induction. The specific coupling method is immaterial to the present disclosure, and the person skilled in the art will appreciate that alternative coupling methods may be implemented in accordance with the herein disclosed embodiments.
In accordance with some embodiments, at least a portion of the first and second contact terminals may extend outwardly from an edge of the expandable enclosure. This may facilitate establishing an electrical connection with the contact terminals.
In accordance with some embodiments at least one physical characteristic may be determined while the electronic device is electrically coupled to the pouch cell battery. This may help to identify faulty pouch cell batteries before they are deployed, for example even during and after battery manufacture, during storage, and during battery pack assembly and/or disassembly. The electronic device may comprise a processor. The electronic device may contain memory, that can store the cell manufacturing information, aiding in pack disassembly, second life use and ultimate cell disposal/recycling.
The first and second contact terminals may be flush with or protrude from an end surface of the expandable enclosure. Although the precise shape of the contact terminals is immaterial to embodiments of the present disclosure, in some embodiments that the contact terminals may be rectangular or circular in cross-section. Depending on the intended use of the battery assembly, in some embodiments the contact terminals may be located at different end surfaces of the expandable enclosure, or may be located at the same end surface. The precise configuration of the contact terminals will be dependent on the intended use of the battery assembly, and, in particular, on any physical dimensional restrictions associated with such use. The contact terminals enable current to be drawn from the pouch cell battery.
The expandable enclosure forms a hermetic enclosure around the internal componentry of the pouch cell battery. The contact terminals may be fashioned from any suitable electrically conductive material, such as, but not limited to nickel and/or aluminum.
The pouch cell battery may have any suitable shape, which may be planar and rectangular. The enclosure may be expandable. The precise shape of the pouch cell battery and the expandable enclosure is immaterial to embodiments of the present disclosure. The described embodiments may work equally well with alternatively shaped pouch cell batteries and expandable enclosures.
The at least one physical characteristic of the cell may comprise any one or more of: temperature, current, voltage, pressure, stress, strain, impedance or electrical resistance. The electronic device may be configured to determine any one or more of these physical characteristics. Each of these physical characteristics provides useful insights to the operation of the pouch cell battery. An unexpectedly high or low voltage may be indicative of a fault in the internal componentry of the pouch cell battery. Voltage and current measurements may be used to determine the capacity of the pouch cell. A low charge capacity may be indicative that the electrolyte is nearing the end of its operational life. Thus, monitoring of physical characteristics of the pouch cell battery also enables important aspects concerning the functional health of the battery cell to be determined.
In use, the expandable enclosure expands as a result of any one or more of: thermal expansion, chemical expansion, or gas evolution or expansion. Expansion increases the pressure, stress, strain, and/or temperature of the pouch cell battery and, specifically, of the expandable enclosure. Monitoring any one or more of these physical characteristics may assist with determining whether the pouch cell battery is operating as expected. Unexpectedly high measured values of pressure, stress, or strain may be indicative of the build-up of undesired gasses within the pouch cell battery. This may provide an indication of imminent failure of the cell. Under normal operating conditions, each one of the physical characteristics may be associated with a range of expected values associated with normal operation of the pouch cell battery. Determined values of the physical characteristics that fall outside the normal range of operation, may be indicative of faulty operation of the pouch cell.
The electronic device may be electrically coupled to the first and second contact terminals by a conductor, such as but not limited to wire bonds extending between the contact terminals and the electronic device. Similarly, the electronic device may be coupled to the first and second contact terminals by soldering, welding, riveting, ultrasonic or laser welding, clamping, or any other suitable means for establishing electrical contact between the electronic device and the first and second contact terminals.
In certain embodiments, wire bonds may be embedded within the material of the expandable enclosure, or overlaid on the expandable enclosure. Where wire bonds are embedded within the material of the expandable enclosure, this may be done during manufacture of the pouch cell battery. Where wire bonds are overlaid on the expandable enclosure, this may be done as a retro-fit after cell manufacture.
Certain embodiments may comprise one or more sensors configured to measure the at least one physical characteristic of the pouch cell battery. The electronic device may be configured to determine the physical characteristics from the measurement received from the one or more sensors. In certain embodiments, the one or more sensors may be distributed around the pouch cell battery at different locations, and each sensor may be operatively coupled to the electronic device, enabling the sensor to communicate with the electronic device. Similarly, in some embodiments the electronic device itself may comprise at least one of the one or more sensors—in other words, at least one of the one or more sensors may be embedded in the electronic device. Different sensors may be configured to measure different physical characteristics. This enables the electronic device to determine different physical characteristics, which in turn enables further information regarding the state of the pouch cell to be determined.
In accordance with some embodiments, the one or more sensors may be located local to the electronic device, in which case they may relate to electronic componentry physically located within the electronic device; or they may be located remotely from the electronic device and operatively connected thereto. The sensors may comprise any one or more of a strain gauge configured to measure stress, tension, and/or pressure; a temperature sensor; a pressure sensor; a voltage sensor; an electrical current sensor; an impedance sensor; or an electrical resistance sensor.
In some embodiments the different sensors may be configured to measure the same physical characteristic at different locations, providing further insight into the state of the pouch cell. In certain instances, this may even provide information regarding the state of specific internal componentry to be determined. Monitoring a physical characteristic at different locations, enables a gradient of the physical characteristic as a function of location to be determined. For example, by monitoring temperature at different locations enables a temperature gradient across the pouch cell battery to be determined, which can provide additional information about the operative state of specific internal battery componentry to be determined. For example, whether a specific component may be malfunctioning. Similar insights may be determined by monitoring other physical characteristics at different locations on the pouch cell battery.
The physical characteristic measured by the one or more sensors need not be the same physical characteristics determined by the electronic device. For example, the one or more sensors may relate to a pressure sensor configured to measure the pressure within the expandable enclosure, in dependence of which the electronic device may determine the internal operating temperature within the expandable enclosure. Similarly, the one or more sensors may be configured to measure strain in the expandable enclosure, in dependence of which the electronic device may determine the internal temperature and/or pressure within the expandable enclosure. It is to be appreciated that these are two non-limiting examples of how a physical characteristic may be determined from sensor data, and that the data measured by the sensors need not necessarily be the same as the physical characteristic determined by the electronic device.
In some embodiments, the electronic device and/or the one or more sensors may comprise an optical sensor configured to measure a characteristic of the pouch cell battery. For example, the optical sensor may be configured to measure any one or more of temperature, gas, chemical concentration, or stress. The electro-magnetic propagation characteristics of a medium change in dependence on the above-mentioned physical characteristics of the medium. A value of the above-mentioned physical characteristics may therefore be determined by measuring propagation characteristics of an optical signal, using an optical sensor. For example, the propagation characteristics of a light signal in a medium change in dependence on the stress applied to the medium. Thus, by monitoring the characteristics of the light signal in the medium, the applied stress may be determined.
In some embodiments, the electronic device and/or the one or more sensors may comprise an ultrasonic sensor configured to measure a characteristic of the pouch cell battery. Comparable to the way in which the aforementioned optical sensors can be used to measure physical characteristics of the pouch cell battery from the propagation characteristics of an electro-magnetic signal, the ultrasonic characteristics of an ultrasonic signal propagating in the pouch cell battery can be used to measure physical characteristics of the pouch cell battery.
In some embodiments, the electronic device and/or the one or more sensors may comprise a mechanical vibration sensor. The vibration sensor may comprise a microelectromechanical system (MEMS) device. The MEMS may be configured to measure mechanical stress/strain, or pressure. Use of MEMS is particularly advantageous given their reliability, size, and speed of measurement.
The pouch cell battery assembly may comprise a wireless transmitter operatively coupled to the electronic device and configured to transmit the determined physical characteristic. For example, the determined physical characteristic may be transmitted to a battery management system (BMS) or any other remotely located device. Similarly, the wireless transmitter may be used to enable the physical characteristics associated with a first pouch cell battery to be shared with other neighboring pouch cell battery assemblies. Similarly, the wireless transmitter may enable sharing physical characteristic data with a battery system controller, which may be located remotely from the pouch cell battery assembly, although in some embodiments it may be located locally to the pouch cell battery assembly.
The pouch cell battery assembly may also comprise a receiver, enabling data transmissions received from other neighboring pouch cell apparatus. This type of information sharing between neighboring pouch cell battery assemblies may be useful when operating the pouch cell battery assemblies in a battery pack.
The wireless transmitter may comprise a near-field communication device configured for short range communication. In some embodiments, the near-field communication device may have a transmission range of up to ten centimeters. In other embodiments, the transmission range may be up to five centimeters. In yet other embodiments the transmission range may be up to two centimeters. In yet further embodiments the transmission range may be less than or equal to one centimeter. In certain embodiments the transmission range may be less than a half wavelength of the frequency used, in the medium through which the transmission is made. An example of a wireless transmitter that may be used in accordance with embodiments of the present disclosure is disclosed in the Applicant's pending patent application number U.S. Ser. No. 16/313,880, the contents of which are incorporated by reference in its entirety, as if fully set forth herein.
In some embodiments, the electronic device may comprise a printed circuit board. In some embodiments the electronic device may be attached to a printed circuit board. The printed circuit board may be rigid, or flexible. In some embodiments, the wireless transmitter may be constituted by electronic components mounted on the printed circuit board. Further, electronic components may be mounted on the printed circuit board, such as one or more sensors. Such further electronic components may form at least a part of the electronic device and may include a microprocessor.
In some embodiments, the expandable enclosure may comprise a sealed edge region, and the electronic device may be at least partly affixed to the sealed edge region. Fixing the electronic device, at least partly, to the sealed edge region is advantageous because the sealed edge region is not subject to the same thermal expansion and stress as the rest of the expandable enclosure. In use, and as previously mentioned, the expandable enclosure may expand, and is designed to accommodate the stresses generated by this expansion. The stresses are minimal at the sealed edge region of the expandable enclosure, providing a mechanically more stable location to which to fix the electronic device, relative to other regions of the expandable enclosure. The sealed edge region may comprise a heat seal. Fixing the electronic device to an external surface of the expandable pouch cell, including the sealed edge region, allows for retrofitting of the electronic device to the pouch cell battery.
In some embodiments, the electronic device may be attached to the pouch cell battery at various different locations on a face of the expandable enclosure. In some embodiments, the electronic device may be located more centrally on a surface of the expandable enclosure, while in other embodiments the electronic device may be attached towards an edge region of the expandable enclosures.
In some embodiments, the electronic device may be configured to measure structural stress experienced by the pouch cell battery due to thermal expansion, or externally applied forces such as generated when the pouch cell battery assembly is dropped, or the forces generated during a rapid deceleration, such as may occur in a road traffic collision. Locating the electronic device more centrally on the surface of the expandable enclosure may be advantageous in such embodiments, where the structural stress experienced by the expandable enclosure may be greater than that experienced at the edges.
The electronic device may be affixed to an internal surface of the expandable enclosure. In such embodiments the electronic device may be provided with a protective cover or conformal coating to isolate it from the battery electrolyte. Alternatively, the electronic device may be made of a material resistant to any corrosive effects of the electrolyte. Fixing the electronic device within the pouch cell battery may be advantageous for determining certain physical characteristics of the pouch cell.
The electronic device may be affixed to the expandable enclosure via an adhesive. For example, an adhesive layer may be provided to fix the electronic device to the internal or external surface of the expandable enclosure. An adhesive strip may be provided to fix the support device to the expandable enclosure. Where an adhesive is used to affix the electronic device to an internal surface of the expandable enclosure, the adhesive is preferably selected to be resistant to any corrosive effects associated with the electrolyte.
In some embodiments, the electronic device may be attached to a support device, which is affixed to the expandable enclosure. The support device may provide additional mechanical stability to the electronic device and, therefore, provides a more mechanically stable mounting point for the electronic device. The support device may enable the pouch cell battery to be more easily retrofitted with the electronic device. In addition to providing mechanical support, the support device may also provide strain relief to the electronic device, reducing the amount of mechanical stress and/or strain experienced by the electronic device when affixed to the expandable enclosure. The support device may be attached to one or more exterior faces of the expandable enclosure. In configurations where the contact terminals are positioned parallel to one another, the support device may be arranged such that it overlaps at least a portion of the expandable enclosure's sealed end region.
In some embodiments a snap-action or press-action mechanical connection may secure the support device to the contact terminals and expandable enclosure, and may also provide an electrical connection between the electronic device and the contact terminals of the pouch cell battery.
The support device may comprise a carrier or a cradle arranged to support the electronic device. The carrier or cradle may be constructed from a plastic material. The carrier or cradle may comprise a printed circuit board or substrate that may be electrically connected to the contact terminals irrespectively of the configuration of pouch cell battery terminals. For example, regardless whether the contact terminals are configured parallel to each other, on opposite sides of the expandable enclosure, or are arranged in any other configuration, the carrier or cradle may still provide electrical coupling between the contact terminals and the electronic device.
In some embodiments, the carrier or cradle may comprise a bus bar, arranged to fit over distal ends of the contact terminals. In the ensuing description any reference to carrier is interchangeable with cradle, and all embodiments described with respect to the carrier apply equally to the cradle.
In accordance with some embodiments the carrier may be configured as a modular unit configured to be integrated into the pouch cell battery. The carrier may comprise the first and second contact terminals, and first and second contact tabs electrically coupled respectively to the first and second contact terminals. The first and second contact tabs extend from the carrier and are arranged to establish electrical contact with the anode and cathode stacks within the pouch cell battery, when the carrier is integrated into the pouch cell battery.
In some embodiments, the carrier may be configured to integrate with the pouch cell battery by fixation to an end face of the pouch cell battery. When the carrier is fixed to the end face of the pouch cell battery, the first and second contact tabs form an electrical contact with the anode and cathode stacks located within the pouch cell battery, thus, enabling current to be drawn from the first and second contact terminals. The modular carrier may be integrated with the pouch cell battery during assembly of the pouch cell battery. The modular carrier simplifies the pouch cell battery assembly process. Since contact terminals are integrated into the carrier module, this removes the need to individually configure the terminals in the pouch cell, which is laborious. Instead, the contact tabs are positioned on the carrier such that when the carrier is fixated to the pouch cell battery they form an electrical contact with the anode and cathode stacks within the pouch cell battery directly, which in turn establishes an electrical connection between the contact terminals and the cathode and anode stacks.
In some embodiments, the carrier may be complementary in shape and size to the pouch cell battery. In particular, the carrier may be complementary in shape and size to the pouch cell face it is intended to be formed integral with. For example, in certain embodiments, the carrier may be shaped and dimensioned to integrate with an edge face of the pouch cell battery. The shape of the modular carrier may be complementary to the shape of the edge face. In some embodiments, the shape of the modular carrier may be complementary to a cross-sectional shape of the pouch cell battery, the cross-section taken across the pouch cell's width, where the edge face of the pouch cell to which the carrier is intended to be integrated with is along the pouch cell's width. In some embodiments, the shape of the modular carrier may be complementary to a cross-sectional shape off the pouch cell battery, the cross-section taken across the pouch cell's length, where the edge face of the pouch cell to which the carrier is intended to be integrated with is along the pouch cell's length.
In some embodiments, the first and second contact terminals may be formed flush with a face of the carrier, whilst in other embodiments the contact terminals may extend from the face of the carrier. In certain embodiments, the contact terminals may extend from a face of the carrier, and may be configured as mechanical fixing points, enabling fixation to an external support structure.
In some embodiments, the carrier may comprise an edge face comprising an adhesive strip arranged to form a seal with the expandable enclosure of the pouch cell battery, when the carrier is integrated with the pouch cell battery. In this way, advantageously a single seal may be formed with the expandable enclosure. This contrasts with prior art solutions, in which each contact terminal forms a separate seal with the expandable enclosure, thus increasing the number of potential sources of a leak. Furthermore, because the present embodiment only requires a single seal between the carrier and the expandable pouch, disassembly of the pouch cell battery assembly is facilitated with respect to prior art solutions which use riveting and/or welding to bind the different components of the pouch cell battery together. Disassembly of a pouch cell battery comprising the integrated carrier requires breaking the seal formed between the carrier and the expandable enclosure, thereby providing access to the internal componentry within the pouch cell.
In some embodiments, the electronic device may be formed integral with the expandable enclosure. For example, the electronic device may be printed onto an internal or external surface of the expandable enclosure.
In accordance with another aspect of the disclosure, there a pouch cell battery assembly comprises a pouch cell battery, and an electronic device configured to determine at least one physical characteristic of the pouch cell battery. The pouch cell battery comprises an expandable enclosure accommodating an anode stack, a cathode stack, and a separator interposed between the anode and cathode stacks. The pouch cell battery comprises first and second contact terminals, the first contact terminal being electrically coupled to the anode stack and the second contact terminal being electrically coupled to the cathode stack. The pouch cell battery assembly may comprise a frame configured to receive the expandable enclosure. The electronic device may be at least partly affixed to the frame, and electrically coupled to the first and second contact terminals.
The frame provides an external structural support to the pouch cell battery, and specifically to the expandable enclosure. The frame improves the ease with which the pouch cell battery assembly may be handled. For example, the ease with which the assembly may be inserted within a housing is improved by use of the frame.
The present aspect may comprise components of the previously described embodiments in various combinations. Additional embodiments associated with the present aspect are outlined below.
In certain embodiments, the frame may be configured to fit around and extend over at least a portion of a sealed edge region of the expandable enclosure, enabling the main faces of the expandable enclosure to expand unimpeded due to expansion of the enclosure. The frame may be configured to grip at least a portion of the sealed edge of the expandable enclosure.
The frame may comprise a hollow cut-out region. The cut-out region may be positioned to align with the region of the expandable enclosure that is subject to the greatest expansion in use. In other words, the hollow cut-out may be aligned with the surface region of the expandable enclosure that is subject to the greatest amount of expansion. In this way, the frame avoids interfering with the normal expansion experienced by the expandable enclosure in use, whilst still imparting structural rigidity to the expandable enclosure. This may be useful when configuring the assembly within a battery pack, or when mounting the assembly on a rail.
The frame may be complementary in shape and dimensions to the pouch cell battery and may be retrofitted to the pouch cell battery. The frame may be configured to circumscribe the expandable enclosure.
In certain embodiments, the electronic device may be at least partly affixed to the frame. The frame provides a mechanically stable mounting point for the electronic device. In certain embodiments, the electronic device may be at least partly co-molded within the frame.
In certain embodiments, the electrical coupling, such as wires or other electrical conductors operatively coupling the electronic device to the contact terminals of the pouch cell battery, may be configured on the frame, or within the frame. The frame may be configured with recesses or apertures dimensioned complementary to the size and shape of the contact terminals. In use, the recesses or apertures may be arranged to receive the two contact terminals, and which recesses or apertures, as the case may be, may be provided with an electrical contact junction in which the electrical wires or other electrical conductors are placed into electrical contact with the contact terminals, thereby electrically coupling the electronic device to the contact terminals.
The frame may be dimensioned such that distal ends of the contact terminals extend beyond distal ends of the frame, thus facilitating electrically coupling the contact terminals to third party devices intended to be powered by the pouch cell battery.
The electronic device may be configured to determine the at least one physical characteristic of the pouch cell battery from a measured physical characteristic of the frame. Since the frame is in physical contact with the pouch cell battery, at least some of the frame's physical characteristics will be at least partly dependent on the pouch cell battery's physical characteristics. For example, the temperature of the frame will be proportional to the temperature of the pouch cell battery. As the temperature of the pouch cell battery increases, so too will the temperature of the frame. Thus, the internal temperature of the pouch cell battery may be determined on the basis of the temperature of the frame. The proportionality between the internal temperature of the pouch cell battery and the temperature of the frame may be calibrated during manufacturing. For a given type of pouch cell battery and frame, the proportionality between the internal temperature of the pouch cell battery and the frame may need to be determined only once, obviating the need to repeat the calibration process for each manufactured pouch cell battery. A similar type of dependency may exist for other physical characteristics.
In some embodiments, at least one of the one or more sensors may be configured on the frame, and the electronic device may be configured to determine the at least one physical characteristics from a measurement received from the sensor located on the frame. The one or more sensors may be formed integral with the frame. For example, the sensor may be formed within the frame. In some embodiments some of the plurality of sensors may be located on the frame, whilst other sensors may be located on or within the pouch cell battery, and the electronic device may be configured to determine one or more physical characteristics from measurements received from the different sensors.
In some embodiments, the frame may comprise two surfaces connected by a hinge. The frame may comprise a closed position in which the two surfaces are configured in opposing relation, and at least partly sandwich the expandable enclosure therebetween, and an open position in which at least one of the two surfaces is rotatable relative to the other about the hinge, and wherein the expandable enclosure is removable from the frame in the open position. When in the closed position, the two surfaces are in opposing relation and define a cavity or recess complementary in shape to the pouch cell battery the frame is configured to receive. In the open positions, one of the surfaces is rotatable relative to the other surface about the hinge, thereby forming a non-zero angle between the two surfaces. In the open position, the pouch cell battery located within the frame is removable.
In some embodiments the hinge may comprise a pin and socket hinge. Alternatively, in other embodiments the hinge may comprise a living hinge. In yet further embodiments the hinge may relate to any suitable hinge enabling rotation of the two frame surfaces relative to one another.
The frame may comprise a locking mechanism to bias the frame in the closed position in use. Any suitable locking mechanism may be used to keep the two surfaces of the frame in fixed relation to prevent escape of the pouch cell battery in use. For example, the locking mechanism may comprise a mechanical locking mechanism, such as a snap-fit mechanism. Similarly, a fastening mechanism may be used. For example, one surface of the frame may be provided with screws, while the other surface may be provided with complementary shaped bore holes configured to receive the screws. The frame may be locked in the closed position by engaging the screws located on one surface with the bore holes located on the opposing surface. Any locking mechanism configured to fix the two surfaces of the frame in the closed position may be used in accordance with embodiments of the present disclosure.
In some embodiments, the frame may comprise a heat sink, configured to absorb heat generated by the pouch cell battery in operation, and assist with cooling of the pouch cell battery. This may help to prevent critical overheating of the pouch cell.
In some embodiments, the frame may comprise a heat exchanger, enabling heat to be conducted to a heat sink. The heat sink may be located externally to the pouch cell battery assembly. Accordingly, the frame may be constructed of a material having good thermal conductivity, to enable the frame to draw heat from the pouch cell battery, and to feed this heat into the heat sink (thermal reservoir). In certain embodiments, the frame may comprise material having a low specific heat capacity, improving the frame's ability to extract heat from the pouch cell and conduct it to the heat sink. In some embodiments, the frame may be constructed from a metal such as aluminum. In some embodiments, the frame may be constructed from graphene, which is a good electrical insulator, but good thermal conductor.
In some embodiments, the heat sink may be located externally to the pouch cell battery assembly, in thermal contact with the frame. By thermal contact is intended an arrangement of the frame relative to the heat sink enabling heat to be exchanged between the frame and the heat sink. In some embodiments, the thermal contact may comprise a physical connection between the frame and the heat sink.
In some embodiments, the frame may comprise an embedded fluid medium, acting as a heat exchanger to draw heat from the pouch cell battery. Heat extracted from the pouch cell battery may be exchanged with the heat sink, by passing the fluid medium through the heat sink.
In some embodiments, the frame may comprise a thermally conductive sheet attached to the front or back surface of the frame and configured to function as the heat exchanger.
In accordance with some embodiments, the electronic device may be configured to determine a physical characteristic of the pouch cell battery from a measurement of the heat exchanger.
In another aspect of the present disclosure, a battery pack comprises a plurality of the above-summarized pouch cell battery assemblies. Such a battery pack shares the same advantages as described above in relation to the previously described aspects of the disclosure and associated embodiments.
In yet a further aspect of the present disclosure, a modular unit for fixation to a pouch cell battery is provided. The pouch cell battery comprises an expandable enclosure accommodating an anode stack, a cathode stack, and a separator interposed between the anode and cathode stacks. The removable modular unit comprises a first contact terminal electrically coupled to a first contact tab; a second contact terminal electrically coupled to a second contact tab; and an electronic device electrically coupled to the first and second contact terminals. When the removable modular unit is fixed to the pouch cell battery, the first contact tab forms an electrical contact with the anode stack, and the second contact tab forms an electrical contact with the cathode stack. This enables current to be drawn from the pouch cell battery via the first and second contact terminals. The electronic device is configured to determine at least one physical characteristic of the pouch cell battery.
The removable modular unit may be integrated with the pouch cell battery during assembly of the pouch cell battery. The removable modular unit simplifies the pouch cell battery assembly process. Since contact terminals are integrated into the carrier module, this removes the need to individually configure the terminals in the pouch cell, which is laborious. Instead, the contact tabs are positioned on the removable modular unit such that when the modular unit is fixated to the pouch cell battery they form an electrical contact with the anode and cathode stacks within the pouch cell battery directly, which in turn establishes an electrical connection between the contact terminals and the cathode and anode stacks.
In a similar way that use of the removable modular unit improves the ease of pouch cell battery assembly, disassembly of pouch cell battery assemblies comprising the removable modular unit, is equally improved, which in turn improves the ease with which the componentry of the pouch cell battery assembly may be recycled.
In some embodiments, the removable modular unit comprises a cradle arranged to receive the electronic device. The removable modular unit may comprise electrical conductors arranged to electrically couple the electronic device to the first and second contact terminals when the electronic device is positioned in the cradle.
In some embodiments, the removable modular unit may be complementary in shape and size to a face of the pouch cell battery to which it is adapted. For example, in some embodiments the removable modular unit may be dimensioned to integrate with an edge face of the pouch cell battery.
In some embodiments, the first and second tabs extend from a first face of the removable modular unit, and the first and second contact terminals extend from a second face of the removable modular unit. The first face being opposite to the second face of the removable modular unit.
Specific embodiments of the disclosure will be described, by way of non-limiting example only, with reference to the accompanying figures.
In the following description of embodiments like numbered reference numerals appearing in different figures will be used to refer to shared features.
Embodiments in which first 110 and second 112 contact terminals extend outwardly from different sides of expandable enclosure are also envisaged. Expandable enclosure 106 may be formed of two correspondingly dimensioned sheets of material, each defining a major face of expandable enclosure 106, bonded at their edges, thus forming the sealed end region 108, and defining an internal volume for housing the internal battery componentry and chemicals, including the electrolyte. First 110 and second 112 contact terminals may be sandwiched between the two major faces and may be configured to, at least partly, extend outwardly from expandable enclosure 106.
In some embodiments, protective film or coating may be provided to cover the contact terminals, at the very least the portion of the contact terminals located internally within expandable enclosure 106. Protective film or coating may serve to protect the portion of the contact terminals that are covered, from corrosion. For example, protective film or coating may protect against corrosion due to contact with electrolyte located within expandable enclosure, and/or from other corrosive agents, including externally located corrosive agents.
Electronic device 104 is electrically coupled to first 110 and second 112 contact terminals, enabling electronic device 104 to be electrically powered by pouch cell battery 102, and obviating the need for a separate power source. The electrical coupling may occur by any means that establishes an electrical path between contact terminals 110, 112 and electronic device 104. In accordance with some embodiments this may be provided by wired connections between electronic device 104 and first 110 and second 112 contact terminals.
Electronic device 104 may be configured to determine at least one physical characteristic of pouch cell battery 102. The at least one physical characteristic may relate to a physical characteristic of pouch cell battery 102, when pouch cell battery 102 is in operation—that is to say, when current and/or voltage is being drawn from the pouch cell battery—although this is by no means essential, and in some embodiments the physical characteristic may relate to a physical characteristic of pouch cell battery 102 when it is idle.
Electronic device 104 may be configured to disregard and/or filter out any current and/or voltage being drawn from the pouch cell battery by electronic device 104 itself. This helps to ensure that in use electronic device 104 is able to determine with greater precision the current and/or voltage being drawn from the pouch cell battery by external devices.
In some embodiments, the at least one physical characteristic may relate to any one or more of the following: temperature of pouch cell battery; current generated by pouch cell battery, including internal currents generated within pouch cell, and current being drawn from pouch cell battery; voltage generated by pouch cell battery; pressure within expandable enclosure 106; stress and/or strain experienced by the components of battery assembly 100, including the stress and/or strain experienced by expandable enclosure 106; electrical impedance associated with pouch cell battery 102; and internal electrical resistance associated with pouch cell battery 102. The at least one determined physical characteristic may subsequently be used to determine an internal state of pouch cell battery 102. In some applications, this may be used to identify faulty battery behavior, and it is envisaged that at least some embodiments may be incorporated into a battery management system (BMS).
Within the present disclosure the term “BMS” has its normal meaning in the art and, in particular, relates to any electronic system that is operatively coupled to a battery, configured to ensure that the battery operates within its safe operating area. The safe operating area is defined as the voltage and current conditions under which the battery is expected to operate without self-damage. For further details, the interested reader is directed to the following Wikipedia website: https://en.wikipedia.org/wiki/Battery management system.
In some embodiments, battery assembly 100 may comprise transmitter 118 in operative communication with electronic device 104, and configured to transmit data processed by electronic device 104, such as the determined at least one physical characteristic of pouch cell battery 102, to a remotely located recipient. In some embodiments, the at least one physical characteristic of pouch cell battery 102 may be transmitted to a BMS. The transmitter 118 may relate to a wireless transmitter, as illustrated in
In some embodiments, the transmission distance may be less than half a wavelength. The transmission frequencies may range from around 400 MHz to around 5 GHz. In some embodiments the transmission frequencies may relate to those used for Short Range Devices (e.g. around 434 MHZ and 860 MHz), and/or those used for ISM bands (e.g. 928 MHz, 2.45 GHz, 5.875 GHz).
In certain embodiments, electronic device 104 may comprise a measurement device, enabling the electronic device 104 to determine at least one physical characteristic of pouch cell battery 102 from a measurement taken by the measurement device. The measurement device may comprise one or more sensors local to electronic device 104. In some embodiments, battery assembly 100 may comprise a plurality of sensors configured to measure physical properties of pouch cell battery 102, which sensors may be located remote from electronic device 104.
The one or more sensors may be positioned at different locations on the expandable enclosure 106 depending on the at least one physical characteristic they are configured to measure. At least some of the one or more sensors may be located internally within the expandable enclosure 106. One or more sensors may be configured in operative communication with electronic device 104, to enable electronic device 104 to determine the at least one physical characteristic from sensor data received from at least one of the one or more remotely located sensors.
Electronic device 104 may be affixed directly to expandable enclosure 106 as shown in
Electronic device 104 or carrier 120 may be affixed to expandable enclosure 106 via an adhesive material. adhesive material may be provided in the form of one or more elongated strips 122 disposed along expandable enclosure 106. In the embodiment of
Electronic device 104 may be affixed to expandable enclosure 104 at any location on or within the expandable enclosure. Some non-limiting examples of alternative placements of electronic device 104 on external surface of expandable enclosure 106, are shown in
Electronic device may comprise at least one measurement device 132 configured to measure at least one of stress, strain, or pressure that pouch cell battery 102 is experiencing due to thermal expansion. Measuring stress, strain, or pressure may provide useful information about the internal state of the battery. Some expansion of pouch cell battery 102 is expected in use. Expansion beyond expected tolerances may be indicative that undesirable internal chemical processes are occurring within the battery that may forewarn of a critical fault. Such expansion may occur as a result of internal chemical reactions resulting in the production of gasses, which is typically symptomatic of a faulty battery. Measurement of stress, strain, or pressure experienced by pouch cell battery 102, enables the early detection of such unwanted internal chemical reactions.
Similarly, at least one measurement device 132 may be configured to measure other physical characteristics of pouch cell battery 102, such as current, voltage, and internal temperature. Measurement of these physical characteristics also enables the early detection of faulty operation of pouch cell battery 102, when the determined operative value of the measured physical characteristic lies outside the expected tolerance range indicative of error-free operation.
In some embodiments, and as shown in the perspective cut-away illustration of
In some embodiments, electronic device 104 may comprise or otherwise be operatively coupled to one or more pressure sensitive conductive material sheets 136, such as velostat™ or linqstat™. One or more pressure sensitive conductive material sheets 136 may be affixed internally to expandable enclosure 106. In embodiments comprising a plurality of pressure sensitive conductive material sheets 136, as illustrated in
Electronic device 104 may comprise or otherwise be operatively coupled to one or more temperature sensitive material sheets, such as a ceramic or polymer material. One or more temperature sensitive sheets may be distributed in accordance with a predetermined pattern internally within expandable enclosure 106, in a similar fashion to previously described pressure sensitive conductive sheets 136. The use of a plurality of temperature sensitive material sheets distributed within expandable enclosure 106, enables the temperature distribution across pouch cell battery 102 to be determined.
In some embodiments, one or more pressure sensitive conductive material sheets 136 and one or more temperature sensitive material sheets may be combined to form an array of temperature and pressure sensitive sensors. One non-limiting way in which this may be achieved is to apply the pressure sensitive material and the temperature sensitive material to a thin sheet of plastic, such as Mylar®, placed within expandable enclosure 106 to form a pressure and temperature sensor array on a single sheet of plastic.
In some embodiments, measurement device may be printed directly onto the internal surface or the external surface of expandable enclosure 106.
Furthermore, bus bar 317, which extends from carrier 316, provides a convenient means for electrically connecting pouch cell battery assembly 300 to other electrical devices, and imparts additional structural rigidity to pouch cell battery assembly 300, and in particular to contact terminals 110, 112.
Carrier 318 may be complementary in shape and dimensions to pouch cell battery 102 end face 324 with which it is integrated. In the illustrated embodiment of
Carrier 318 may be integrated into pouch cell battery 102 during assembly of pouch cell battery 102. To this end, carrier 318 may be provided with adhesive sealant 326 formed along edge faces 328 of carrier 318. During assembly, as carrier 318 is inserted onto edge face 324 of pouch cell battery 102, adhesive sealant 326 bonds with at least a portion of internal faces of expandable enclosure 106 of pouch cell 102. When compared with convention pouch cell design, in which a seal is formed along each of two contact terminals, the present embodiments reduce the number of separate required seals.
During insertion of carrier 318 on to edge face 324, first 320 and second 322 tabs form a contact with the electrodes located within pouch cell battery 102, thereby providing a conductive path for current to flow to first 110 and second 112 contact terminals.
In some embodiments, carrier 318 may be formed of a rigid polymer material, such that when integrated into edge face 324 of pouch cell 102, it provides rigidity and structural support to pouch cell 102. Electronic device 104 may be affixed to carrier 318, as described in relation to preceding embodiments. Similarly, electronic device 104 may be at least partly embedded in carrier 318. Carrier may be configured with conductive connections electrically connecting electronic device 104 with first 110 and second 112 contact terminals, enabling electronic device 104 to be powered by pouch cell battery 102 in a similar manner as described in relation to preceding embodiments. The electrically conductive connections may be configured internally to carrier 318.
First 110 and second 112 contact terminals of the illustrated embodiment of
A pouch cell battery assembly 400 in which electronic device 104 is affixed to first 110 and second 112 contact terminals extending from opposite ends of pouch cell battery 102, in accordance with an embodiment, is illustrated in
A further embodiment of a pouch cell battery assembly 500 comprising frame 570, is illustrated in
Frame 570 is dimensioned such that, in use, frame 570 extends around and grips sealed end region 108 of expandable enclosure 106. Frame 570 may comprise front 572 and back faces 574 arranged to sandwich expandable enclosure 106 therebetween. Sealed end region 108 of expandable enclosure 106 is gripped between front 572 and back face 574 of frame 570. Front 572 and back 574 faces may be connected by hinge 576 arranged on side edge of the frame 570.
Hinge 576 defines a rotational axis enabling frame 570 to pivot from a closed position in which expandable enclosure 106 is held within frame 570, and an open position in which front 572 and back 574 faces of frame are in a non-zero angled relation about the rotational axis of hinge 576.
Hinge 576 may relate to a separate component affixed to front 572 and back 574 faces of frame 570, or it may be formed integrally with front 572 and back 574 faces.
Frame 570 may be configured with recess 578 arranged to receive electronic device 104, enabling at least part of electronic device 104 is affixed to frame 570. Electronic device 104 may be configured to determine the at least one physical characteristic of pouch cell battery 102 from one or more measured physical characteristics of frame 570. For example, internal temperature of pouch cell battery 102 may be inferred from a temperature measurement of frame 570.
In some embodiments, frame 570 may comprise a flexible sheet material, such as flexible plastic material substrate made of polymer such as a polyimide, PEN, PEEK, or a polyester such as PET. Frame 570 may incorporate electronic circuitry in accordance with Flex-Circuit conventions, including electronic device 104 and/or one or more sensors operatively coupled to electronic device 104 configured to measure a property of pouch cell battery 102. In certain embodiments, flexible sheet material may be embedded within frame 570/Frame 570 may comprise recesses to accommodate at least a portion of first 110 and second 112 contact terminals. Distal ends 114 of first 110 and second 112 contact terminals may extend beyond frame 570, to facilitate electrical connection of pouch cell battery 102 with an external device.
In some embodiments, rectangular inner perimeter of frame 570 may be provided with adhesive ribbon 590 to fix pouch cell battery 102 to frame 570. Further electronic components, such as microprocessor and/or wireless transmitter (not shown) may be mounted on or extend on or within the frame 570.
In certain embodiments, frame 570 may be configured with additional recesses for placement of any one or more of probes, sensors, valves, vents, or other circuitry to contact or pass into or out of pouch cell battery 102. Such componentry may be recessed into frame 570 or otherwise fixed to it. Electronic device 104 may be connected to first 110 and second 112 contact terminals in a similar manner as described in relation to previous embodiments.
In some embodiments, and as illustrated in
Temperature sensor 608, such as thermocouple, thermistor or similar device, may extend lengthwise onto at least a portion of heat exchanger 602, and may be configured to measure the temperature of heat exchanger 602. Temperature sensor 608 may be at least partly affixed to frame 570, and may extend back to electronic device, or otherwise be coupled to electronic device 104. Temperature sensor 608 is configured to capture temperature measurements associated with the temperature of heat exchanger 602, which in turn is associated with the internal operating temperature of pouch cell 102. Temperature sensor 608 may itself be flexible to mitigate for expansion of expandable enclosure 106 in use. In accordance with some embodiments, temperature data may be used to enable improved active temperature control of pouch cell battery 102 during use, during charging, or during warm up prior to start-up of the battery. In some embodiments, the temperature data may be used to improve active temperature control of individual cells.
Heat exchanger 602 may be configured to exchange heat drawn from pouch cell battery 102 with the surrounding atmosphere. In certain embodiments, heat exchanger 602 may be thermally connected to heat sink (not shown) located externally from pouch cell battery assembly 100. In such embodiments, heat exchanger 602 is configured to conduct heat drawn from pouch cell battery 102 to heat sink. Use of heat exchanger 602 improves temperature control, such as cooling, of pouch cell battery 102.
Heat exchanger 602 may comprise a lip 610 extending from bottom edge of frame 570. Lip 610 may be configured for engagement with an external cooling device, such as heat sink, to help further control the temperature of pouch cell. Thermally conductive sheet 604 may be sandwiched between first 572 and second 574 faces of frame 570 in a similar manner to pouch cell battery 102, with a portion of the thermally conductive sheet 604 extending out of the bottom edge of the frame to form lip 610. Frame 570 may comprise a channel configured in the bottom edge to enable thermally conductive sheet 604 to extend out of bottom edge. Lip 610 may be configured to engage with liquid-based heat sink, thereby enabling more heat to be drawn from pouch cell battery 102, preventing overheating of pouch cell battery 102.
In some embodiments, frame 570 may comprise a liquid-based heat exchanger. For example, frame 570 may comprise a fluid channel configured to enable fluid to flow through frame 570. As the fluid flows through frame 570, it draws heat from frame 570, facilitating cooling of frame 570 and of pouch cell battery 102. In accordance with some embodiments, the fluid may be output to an externally located heat sink.
In certain embodiments, heat exchanger 602 may be thermally connected to external heat source, thereby enabling heat exchanger 602 to heat pouch cell battery 102. This may be desirable where pouch cell battery is operated in very cold environments, which may otherwise adversely impact performance of pouch cell battery 102.
The temperature of the pouch cell may be inferred from measuring the temperature of any one of frame 570, and sheet 604, by temperature sensor 608. Since pouch cell battery 102 is in physical contact with frame 570, and/or thermally conductive sheet 604, the temperature of frame and/or thermally conductive sheet 604 are correlated to that of pouch cell battery 102. The correlation may be calibrated during an initial configuration process, which may occur at the point of manufacture or assembly. Temperature sensor 608 may measure the temperature of sheet 604 and/or frame 570 itself, wherefrom the temperature of pouch cell 102 may be determined.
In some embodiments, temperature sensor 608 may extend along back face 574 of frame 570 in the shape of a rod, as illustrated in
A stress or pressure gauge sensor may be configured on at least a part of frame 570 and/or sheet 604. Pressure and/or stress measurements may provide important information about the internal operating state of pouch cell battery 102. In particular, as pouch cell 102 expands in use, the internal pressure increases and this change may be monitored by an externally placed stress or pressure gauge sensor. The pressure of the pouch cell may also be determined by measuring through a strain gauge placed outside expandable enclosure. A strain gauge may be attached to the frame or may alternatively be attached to expandable enclosure itself.
Further embodiments are envisaged in which frame 570 does not comprise thermally conductive sheet 604, and in which one or more measurement sensors may be at least partly located on main face of expandable enclosure 106, and configured to operate in a similar manner as to what has previously been described.
In certain embodiments, electronic circuitry comprising electronic device 104 may be printed directly on to expandable enclosure 106.
One or more sensors disposed in the electronic device and/or connected to the electronic device may also comprise optical sensors, and/or ultrasonic sensors.
The pouch cell battery assemblies disclosed herein may be assembled into a battery pack.
The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, and are not intended to be exhaustive or limiting. Multiple modifications and variations of the disclosed embodiments will be apparent to those of ordinary skill in the art, without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Certain features of the present disclosure, which are, for clarity, described in the context of separate embodiments, may also be combined in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the disclosure. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.
Although the disclosure has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20197599.2 | Sep 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/075954 | 9/21/2021 | WO |
