Patent Application
20240213568
The present application relates to a battery pack, an electric tool, and an electric vehicle.
In the field of batteries that generate heat during use (for example, lithium ion secondary batteries), improving heat dissipation characteristics, which are ease of heat dissipation, is desirable. Further, considering that application of secondary batteries is expanding to fields of electric tools, electric vehicles, and the like, improving weight reduction and vibration resistance characteristics of battery packs containing secondary batteries is desirable.
For example, a battery pack is disclosed having improved heat dissipation characteristics while maintaining vibration resistance characteristics by using a buffer member in which a resin with high thermal conductivity is mixed with rubber particles. Further, a power module is disclosed in which rigidity is improved while cooling performance is secured by a cooling insulating layer in which soft and hard insulating layers are laminated in a thickness direction.
The present application relates to a battery pack, an electric tool, and an electric vehicle.
A rubber member containing a thermally conductive material used in the technique described in Background section has a high specific gravity, and thus is disadvantageous from a viewpoint of weight reduction characteristics. Further, since the rubber member has a small Young's modulus, rigidity is reduced. For this reason, there is a possibility that resonance may occur particularly in a low frequency band (for example, 200 Hz or less), which is disadvantageous from a viewpoint of vibration resistance characteristics. A further technique described in Background section is disadvantageous from the viewpoint of weight reduction characteristics because a thermally conductive member with a high specific gravity is used. Further, since thicknesses of a hard insulating member and a soft insulating member are reduced, the rigidity is reduced, and there is a possibility that resonance may occur in a low frequency band, which is disadvantageous from the viewpoint of vibration resistance characteristics. As described above, a need for improvement from the viewpoint of, for example, weight reduction characteristics and vibration resistance characteristics in a low frequency band is desirable.
In an embodiment, the present application relates to providing a battery pack having improved various characteristics such as weight reduction characteristics, and an electric tool and an electric vehicle including the battery pack.
The present application, in an embodiment, is a battery pack including:
Specific gravity: first insulating member<second insulating member (1)
Young's modulus: first insulating member>second insulating member (2)
Thermal conductivity: first insulating member<second insulating member (3)
According to an embodiment, it is possible to improve the weight reduction characteristics and the like of the battery pack. Note that, the contents of the present application are not to be construed as being limited by the effects exemplified in the present description.
The present application will be described below in further detail including with reference to the drawings.
One or more embodiments are described below including preferred examples of the present technology, and the contents of the present application is not limited thereto. Note that, members shown in the claims are not specified as members of the embodiments. In particular, unless otherwise described, the present application is not intended to be limited by description regarding, for example, dimensions, materials, and shapes of constituent members described in the embodiments, relative arrangements thereof, and descriptions of directions such as upward, downward, left, and right and the like, which are merely illustrative examples. Note that, sizes, positional relationships, and the like of the members illustrated in the drawings may be exaggerated for clarity of description, and, only some of the reference numerals may be illustrated, or a part of an illustration may be simplified, in order to prevent the illustration from being complicated. Furthermore, in the following description, the same names and reference numerals indicate the same or similar members, and redundant descriptions will be appropriately omitted.
First, in order to facilitate understanding of the present application, problems to be considered in will be described while describing techniques related to the present application.
First, rigidity of a cushioning member applied to the battery pack will be described. A cushioning member of a cantilever beam in which one side (a left side when facing the drawing in the present example) is fixed and the other side (a right side when facing the drawing in the present example) is a free end is considered.
The rigidity against a force FA in a case where the downward force FA is applied to a free end side of the cushioning member 1 is considered. In a case where the examples shown in
It is also necessary to pay attention to resonance of the cushioning member. Here, resonance is a phenomenon that occurs when a natural frequency of a structure coincides with a frequency input from the outside. When resonance occurs, an external input is transmitted to the structure with an amplitude many times, and in extreme cases, the structure may be damaged. For example, in a case where a rubber member with low rigidity or the like is used as a cushioning member of the battery pack, such cushioning member can attenuate vibration in a high frequency band, but causes resonance in a low frequency band. For example, as shown in
In the technique described in the Background section, a cushioning member is formed by mixing a highly thermally conductive resin with a rubber material. A rubber member containing a thermally conductive material is excellent in heat dissipation characteristics, but has a specific gravity of about 1.0 to 3.5 and a Young's modulus of less than 1.0 MPa. In other words, it becomes a cushioning member with a high specific gravity, which is disadvantageous in a battery pack that is requires to be lightweight. Further, the rubber material has a low Young's modulus and thus has low rigidity. Low rigidity leads to a lower resonance point of the internal structure, which may cause resonance in the low frequency band in which the battery pack can be used, potentially damaging the internal structure of the battery pack.
Further, in a further technique described in the Background section, a cushioning member is composed of two thermally conductive members, a soft member and a hard member. Both of the two members have high thermal conduction characteristics and thus are excellent in heat dissipation characteristics, but a general thermally conductive member has a specific gravity of about 1.0 to 3.5 and a Young's modulus of less than 1.0 MPa. Since the cushioning member is composed of materials with a high specific gravity, it is disadvantageous in a battery pack that is required to be lightweight. Further, while the Young's modulus of a hard thermally conductive member may be 10 to 50 MPa or more, the Young's modulus of a soft thermally conductive member is less than 1.0 MPa. Further, in the cushioning member, the two members are stacked in the thickness direction, and the thickness of each cushioning member becomes thinner, so that the rigidity is reduced as compared with that of the cushioning member composed of a uniform material. As a result, the resonance point of the internal structure decreases, resonance occurs in the low frequency band in which the battery pack can be used, and the internal structure of the battery pack may be damaged. Based on the above, the present application will be described in further detail below based on one or more embodiments.
A battery unit 20 is housed in the exterior case 10. The battery unit 20 includes a battery 21 and a battery holder 22 that houses and holds the battery 21. The battery 21 is, for example, a cylindrical lithium ion secondary battery, but a battery other than a lithium ion secondary battery may be used as the battery 21. The battery 21 has a positive electrode terminal 23A at one end and a negative electrode terminal 23B at the other end. In the following description, in a case where either the positive electrode or the negative electrode may be used, it is appropriately referred to as the terminal 23.
In the present embodiment, the battery unit 20 includes nine batteries 21. For example, three batteries 21 are disposed in an X-axis direction in
The battery holder 22 is composed of, for example, resin. The battery holder 22 holds the battery 21 at a predetermined positions and secures insulation between each battery. The battery holder 22 has the number of cylindrical portions 22A corresponding to the number of the battery 21. In the present embodiment, the nine cylindrical portions 22A are integrated, but may have separate configurations. A diameter of the cylindrical portions 22A is substantially equal to an outer diameter of the battery 21. The battery 21 is inserted into the cylindrical portion 22A. As a result, a side surface near the center of the battery 21 is held in the cylindrical portion 22A.
A tab 24, which is an example of a conductive member, is connected to one terminal 23 of the battery 21, for example, the terminal 23 disposed on an upper side in a Z-axis direction. Further, a tab 25 is connected to the other terminal 23 of the battery 21, for example, the terminal 23 disposed on a lower side in the Z-axis direction. The tab 24 and the tab 25 electrically connect the nine batteries 21 to each other. In the present embodiment, a set (three sets) of three batteries 21 connected in series is connected in parallel (three series and three parallel connections). The tab 24 and the tab 25 are connected to the terminal 23 by a known method such as laser welding or resistance welding.
A spacer member is disposed between the exterior case 10 and the battery 21. For example, a spacer member 26 is disposed between the exterior upper case 10A and the terminal 23 of the battery 21 located on the upper side in the Z-axis direction. Further, a spacer member 27 is disposed between the exterior lower case 10B and the terminal 23 of the battery 21 located on the lower side in the Z-axis direction. The spacer member 26 and spacer member 27 are members that improve the vibration resistance characteristics and heat dissipation characteristics of the battery pack 100 in a well-balanced manner, and also function as a cushioning member.
Next, the spacer member according to the present embodiment will be described with reference to
As shown in
Further, the spacer member 26 includes a foam 261 that has a substantially rectangular outer edge as a whole and a plate-like shape, and a highly thermally conductive member 262 that is provided inside the foam 261 in a substantially circular shape. The highly thermally conductive member 262 according to the present embodiment includes nine highly thermally conductive members (highly thermally conductive members 262A to 262I). Note that, in the following description, in a case where it is not necessary to particularly distinguish individual highly thermally conductive members, they are collectively referred to as the highly thermally conductive member 262 as appropriate. In the present embodiment, the foam 261 corresponds to a first insulating member, and the highly thermally conductive member 262 corresponds to a second insulating member. Note that, the spacer member 27 also includes a foam 271 and a highly thermally conductive member 272.
As shown in
Further, as shown in
As shown in
Furthermore, as shown in
Furthermore, as shown in
Furthermore, as shown in
The foam 261 and the highly thermally conductive member 262 according to the present embodiment satisfy the following relationship.
For specific gravity,
Therefore, in a case of the same volume, mass of the foam 261 is smaller than mass of the highly thermally conductive member 262.
As a method for measuring specific gravity, JIS Z 8807 “Methods for measuring density and specific gravity of solid” is used.
For Young's modulus,
Therefore, as a proportion of the foam 261 in the spacer member 26 increases, the rigidity of the spacer member 26 increases.
As a method for measuring Young's modulus, for a resin material, JIS K 7161-1 “Plastics-Determination of tensile properties” and JIS K 7161-2 “Plastics-Determination of tensile properties” are used.
As a method for measuring Young's modulus, for a rubber member, JIS K 6250 “Rubber-General procedures for preparing and conditioning test pieces for physical test methods”, JIS K 6251 “Rubber, vulcanized or thermoplastic-Determination of tensile stress-strain properties”, and JIS K 6272 “Rubber-Tensile, flexural and compression test equipment (constant rate of traverse)” are used.
For thermal conductivity,
Therefore, the highly thermally conductive member 262 transfers heat more easily than the foam 261.
As a method for measuring thermal conductivity, JIS A 1412-1 “Test method for thermal resistance and related properties of thermal insulations” or JIS A 1412-2 “Test method for thermal resistance and related properties of thermal insulations” is used.
As the foam 261, for example, a foam containing at least one of polypropylene, polyethylene, polyphenylene ether, polyester, and polyurethane can be used.
As the highly thermally conductive member 262, a member having flexibility (bending property) in which a thermally conductive filler is contained in a base material can be used. Examples of the base material include those composed of at least one of silicone rubber, acrylic rubber, urethane rubber, styrene-butadiene rubber, and elastomer. Further, examples of the thermally conductive filler include carbon, graphite, alumina, aluminum hydroxide, boron nitride, and ceramic, or a combination of two or more thereof.
As an example, as the foam 261 and the foam 271, those having a specific gravity within the range of 0.05 to 0.3, a Young's modulus within the range of 30 to 100 MPa, and a thermal conductivity within the range of 0.01 to 0.3 W/m·K are used. Further, as the highly thermally conductive member 262 and the highly thermally conductive member 272, those having a specific gravity within the range of 1.5 to 3.5, a Young's modulus within the range of 0.05 to 1.0 MPa, and a thermal conductivity within the range of 1.0 to 15 W/m·K are used.
The operation of the battery pack 100 according to the present embodiment will be described with reference to
Next, the effects obtained by the present embodiment will be described. According to the battery pack 100 according to the present embodiment, various characteristics required for the battery pack can be improved in a well-balanced manner. Specifically, the heat dissipation characteristics, vibration resistance characteristics, and weight reduction characteristics required for the battery pack can be improved in a well-balanced manner.
A point that various characteristics can be improved by the battery pack 100 according to the present embodiment will be described in comparison with a comparative example.
As shown in
The spacer member 36 includes a foam 361 and a highly thermally conductive member 362. As shown in
First, evaluation results of heat dissipation characteristics will be described. Evaluation of various characteristics of the battery pack according to the present embodiment and the battery pack according to the comparative example was performed based on simulation. An example of a simulation method for evaluating heat dissipation characteristics will be described with reference to
The evaluation results of heat dissipation characteristics are shown in
As shown in
Next, evaluation results of vibration resistance characteristics will be described. Simulation conditions are as follows. Two surfaces of a top surface and a bottom surface of the exterior case of the battery pack (battery packs 100, 100A) were fixed. Then, the battery pack was vibrated in a direction substantially parallel to a longitudinal direction of the battery as an excitation direction, and the resonance point of the battery at this time was calculated. A method for measuring the resonance point is as follows. The battery pack is fixed to a vibration tester, and the frequency is swept from the low frequency band to the high frequency band for excitation. At this time, a sensor is attached to an internal structure such as a battery or a tab to measure acceleration. Further, a sensor is also attached to the exterior case to measure acceleration. A relative acceleration (hereinafter, also referred to as relative acceleration as appropriate) between the measured acceleration of the internal structure and the acceleration of the exterior case was compared, and the frequency at which a peak value of the difference was obtained was defined as the resonance point.
Further, in both the battery packs 100 and 100A, a volume ratio of the highly thermally conductive member and the foam was set to 1:1, and the thicknesses of the spacer members 26 and 36 of the respective battery packs were set to be the same.
The evaluation results of vibration resistance characteristics are shown in
As shown in
Next, evaluation results of weight reduction characteristics will be described. The specific gravity of a rubber member having thermal conductivity (a thermally conductive rubber member), a hard thermally conductive member, and a soft thermally conductive member that are generally used are as shown in Table 1 below. Note that, physical property values of the thermally conductive rubber member and the hard thermally conductive member were estimated from the specific gravity of a general thermally conductive member.
The volume of the spacer member was set to 20,000 mm3, and the mass of the spacer member of Patent Document 1: Japanese Patent Application Laid-Open No. 2019-125449 (also referred to as Document 1), Patent Document 2: Japanese Patent Application Laid-Open No. 2015-76442 (also referred to as Document 2), and the present embodiment described above was determined using the specific gravity in Table 1. The mass of the spacer member corresponding to Document 1 was determined as being composed of one material of a thermally conductive rubber member, and the mass of the spacer member corresponding to Document 2 was determined as having a configuration in which a hard thermally conductive member and a soft thermally conductive member were laminated in the thickness direction. Further, as in Document 2 and the present embodiment, for the spacer member composed of two materials, the ratio of the volumes composed of the respective materials was set to 1:1. The determined mass (the range of mass considered from the range of specific gravity) is shown in Table 2.
From Table 2, it can be found that the spacer member according to the present embodiment has a mass ratio of 50 to 80% as compared with the spacer member corresponding to Document 1 or Document 2, and the weight reduction characteristics are improved. Since the weight of the spacer member can be reduced, the weight of the entire battery pack can be reduced.
As described above, in the battery pack according to the present embodiment, there is no configuration that blocks heat transfer, and the heat of the battery can be effectively transferred to the exterior case through the highly thermally conductive member, and, the resonance point can be increased by forming the highly thermally conductive member surrounded by the foam, furthermore, the weight of the spacer member can be reduced by forming a configuration in which the foam surrounds the highly thermally conductive member, instead of a laminated structure of the highly thermally conductive member and the foam, therefore, the heat dissipation characteristics, vibration resistance characteristics, and weight reduction characteristics of the battery pack can be simultaneously improved.
Next, a second embodiment will be described. Note that, in the description of the second embodiment, the same or similar configurations in the above description are denoted by the same reference numerals, and redundant description is appropriately omitted. Further, the matters described in the first embodiment can be applied to the second embodiment unless otherwise specified.
The second embodiment is an embodiment in which the ranges of the volume ratio of the highly thermally conductive member 262 to the spacer member 26 (the volume proportion occupied by the highly thermally conductive member 262 in the entire volume of the spacer member 26) and the volume ratio of the highly thermally conductive member 272 to the spacer member 27 are optimized. Note that, in the following description, the highly thermally conductive member 262 will be described as an example, but the matters described below can also be applied to the highly thermally conductive member 272 unless otherwise specified.
The volume ratio of the highly thermally conductive member 262 to the spacer member 26 is preferably 22% or more and 50% or less as shown in
First, heat dissipation characteristics will be considered. The horizontal axis of the graph shown in
The cell maximum temperature ratio in a case where the volume ratio of the highly thermally conductive member 262 was 0%, that is, all the spacer members 26 are composed of the foam 261, was set to 100%. Further, a simulation result of the cell maximum temperature ratio in a case where all the spacer members 26 are composed of the highly thermally conductive member 262 (volume ratio 100%) was about 78%. Assuming that there is a first-order correlation relationship between the result when the volume ratio of the highly thermally conductive member 262 is 0% and the result when the volume ratio is 100%, this relationship (a first-order straight line) is indicated by a prediction line LNC. The prediction line LNC can also be considered as an example in which the nine highly thermally conductive members 262 are equally disposed regardless of the position of the battery 21. Further, as a result of plotting the cell maximum temperature ratio determined by the simulation, a curved line LND was obtained.
As shown in
Next, vibration resistance characteristics will be considered. The horizontal axis of the graph shown in
The simulation result in a case where the volume ratio of the highly thermally conductive member 262 was 0%, that is, all the spacer member 26 are composed of the foam 261, was about 1000 Hz. Further, the simulation result in a case where all the spacer member 26 are composed of the highly thermally conductive member 262 was about 50 Hz. Assuming that there is a first-order correlation relationship between the result when the volume ratio of the highly thermally conductive member 262 is 0% and the result when the volume ratio is 100%, this relationship (the first-order straight line) is indicated by the prediction line LNE. Further, as a result of plotting determined by the simulation, a curved line LNF was obtained.
The higher the ratio of the foam 261 that is hard is, the higher a rigidity value increases, so that the resonance point can be brought into the high frequency band. Further, from the simulation results, when the volume ratio of the highly thermally conductive member 262 is 50% or less, the resonance point can be made larger than the prediction line LNE, which is a prediction line. On the contrary, when the volume ratio of the highly thermally conductive member 262 was greater than 50%, the resonance point was smaller than the prediction line LNE, which is the prediction line. This is because when the volume ratio of the highly thermally conductive member 262 is 50% or less, the diameter of the battery 21 is larger than that of the highly thermally conductive member 262, but when the volume ratio of the highly thermally conductive member 262 is greater than 50%, the diameter of the highly thermally conductive member 262 is larger than that of the battery 21. In other words, when the volume ratio of the highly thermally conductive member 262 is greater than 50%, the diameter of the highly thermally conductive member 262 is larger than the diameter of the battery (here, the cell), and thus the entire terminal surface (the terminal surface PRA or PRB) of the battery comes into contact with the highly thermally conductive member 262 that is a soft layer through the tab (the tab 24 or 25). In other words, since it comes into contact with only the highly thermally conductive member 262, which is a layer with a low Young's modulus, the resonance point becomes smaller, and the vibration resistance characteristics in the low frequency band deteriorates. On the contrary, in a case where the volume ratio of the highly thermally conductive member 262 is 50% or less, the diameter of the battery is larger than the diameter of the thermally conductive member. In other words, both the foam 261 and the highly thermally conductive member 262 are disposed at a position overlapping a portion where the terminal surface is projected onto the spacer member, and the terminal surface of the battery is in contact with both the foam 261 and the highly thermally conductive member 262 through the tab. Since the foam 261 has a higher Young's modulus than that of the highly thermally conductive member 262 and is excellent in vibration resistance characteristics in the low frequency band, not only the highly thermally conductive member 262 but also the foam 261 is in contact with the terminal surface of the battery, so that the resonance point increases and the vibration resistance characteristics in the low frequency band are improved. Therefore, from a viewpoint of vibration resistance characteristics for the purpose of preventing resonance of the internal structure, the volume ratio of the highly thermally conductive member 262 is preferably 50% or less.
Next, weight reduction characteristics will be considered. Table 3 shows the mass of the spacer member 26 according to the volume ratio of the highly thermally conductive member 262. As in the first embodiment, the volume of the spacer member 26 was set to 20,000 mm3, and the specific gravity shown in Table 1 of the first embodiment was used as the specific gravity.
From the results shown in Table 3, by reducing the volume ratio of the highly thermally conductive member 262 that is soft and has a high specific gravity to 25%, the mass of the spacer member 26 could be reduced by about 40% as compared with the case of the volume ratio of 50%.
From the above, it has been found that the volume ratio of the highly thermally conductive member 262 in the spacer member 26 is preferably 22% or more and 50% or less in order to improve the heat dissipation characteristics, vibration resistance characteristics, and weight reduction characteristics of the battery pack in a well-balanced manner. Further, it has been found that the volume ratio of the highly thermally conductive member 272 in the spacer member 27 is preferably 22% or more and 50% or less.
Further, the vibration resistance characteristics could be improved by a configuration in which both the foam 261 and the highly thermally conductive member 262 were disposed at a position overlapping the portion where the terminal surface was projected on the spacer member 26. In such a configuration, the heat of the battery can be efficiently transferred to the exterior case 10 by the highly thermally conductive member 262, and further, by reducing the volume ratio of the highly thermally conductive member 262 that is soft and has a high specific gravity, not only the vibration resistance characteristic but also the heat dissipation characteristic and weight reduction characteristic can be simultaneously improved.
Although the embodiments of the present application have been specifically described herein, the contents of the present application are not limited thereto the embodiments described above, and thus is suitably modifiable.
In a case where the spacer member has a rectangular shape and the highly thermally conductive member is provided relatively close to the center, heat transferred from a part of the spacer member near a corner to the exterior case can be reduced. Therefore, a highly thermally conductive member may be disposed on at least a part of a peripheral edge portion (a portion including a part near the periphery) of the spacer member. Then, the highly thermally conductive member disposed on the peripheral edge portion of the spacer member and at least a part of the highly thermally conductive member disposed to face a terminal portion of the battery may be connected to each other.
For example, as shown in
Further, as shown in
Note that, all of the highly thermally conductive members 262A to 262I may be connected to a highly thermally conductive member provided near a corner or the entire periphery edge. However, as described in the second embodiment, the volume ratio of the highly thermally conductive member is preferably in an appropriate range.
The arrangement position of the spacer member described above is not limited to the arrangement position described in the above-described embodiments. For example, the spacer member, specifically, the foam and the highly thermally conductive member forming the spacer member may be disposed to be in contact with the inner surface of the side surface of the exterior case. Then, the highly thermally conductive member may be in contact with at least a part of the side surface (a body portion forming a peripheral surface) of the battery. Also with such a configuration, heat generated from the battery can be released to the side surface of the exterior case.
In a case where the tab is small in the embodiments described above, there may be an aspect in which the entire tab is in contact with the highly thermally conductive member. Further, there may be no tab, and in this case, the terminal of the battery and the highly thermally conductive member can be in direct contact with each other.
In the embodiments described above, the battery pack has two spacer members, but may have one spacer member, or the battery pack may have three or more spacer members.
In the embodiments described above, the shape of the highly thermally conductive member is substantially circular so as to correspond to the shape of the terminal of the battery, but the present application is not limited thereto. The shape of the highly thermally conductive member may be a rectangular shape, a triangular shape, or the like. Further, in the embodiments, an example in which the foam and the highly thermally conductive member are integrally molded has been described, but the foam and the highly thermally conductive member may be formed in different processes and then integrated by adhesion or the like.
The matters described in the above-described embodiments and modification example can be appropriately combined. Further, the materials, processes, and the like described in the embodiments are merely examples, and the contents of the present application are not limited to the exemplified materials and the like.
The battery pack according to the present application can be mounted on an electric tool, an electric vehicle, various electronic devices, or the like, or can be used for supplying electric power.
An example of an electric driver as an electric tool to which the present technology can be applied will be schematically described with reference to
Each of the battery pack 430 and the motor controller 435 may be provided with a microcomputer (not illustrated) so that charge/discharge information of the battery pack 430 can be communicated with each other. The motor controller 435 can control operation of the motor 433 and cut off power supply to the motor 433 when there is an abnormality such as over discharge.
As an example in which the present application is applied to a power storage system for an electric vehicle,
In this hybrid vehicle 600, an engine 601, a generator 602, and an electric power driving force conversion device (a DC motor or an AC motor, hereinafter, simply referred to as “motor 603”), a driving wheel 604a, a drive wheel 604b, a wheel 605a, a wheel 605b, a battery 608, a vehicle control device 609, various sensors 610, and a charging port 611 are mounted. As the battery 608, the battery pack according to the present application or a power storage module equipped with a plurality of battery packs according to the present application can be applied.
The motor 603 is operated by the electric power of the battery 608, and a rotational force of the motor 603 is transmitted to the driving wheels 604a and 604b. The electric power generated by the generator 602 can be stored in the battery 608 by the rotational force generated by the engine 601. The various sensors 610 control an engine speed using the vehicle control device 609 and control an opening degree of a throttle valve (not illustrated).
When the hybrid vehicle 600 is decelerated by a braking mechanism (not illustrated), a resistance force during deceleration is applied to the motor 603 as a rotational force, and regenerative power generated by this rotational force is stored in the battery 608. The battery 608 can be charged by being connected to an external power source through the charging port 611 of the hybrid vehicle 600. Such an HV vehicle is referred to as a plug-in hybrid vehicle (PHV or PHEV).
Note that, a secondary battery according to the present application can also be applied to a miniaturized primary battery and used as a power source of a tire pressure monitoring system (TPMS) built into the wheels 604 and 605.
Although the series hybrid vehicle has been described above as an example, the present application is also applicable to a parallel system using an engine and a motor together or a hybrid vehicle combining a series system and a parallel system. Furthermore, the present application is also applicable to an electric vehicle (EV or BEV) and a fuel cell vehicle (FCV) that runs only by a drive motor without using an engine.
It should be understood that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-161512 | Sep 2021 | JP | national |
The present application is a continuation of PCT patent application no. PCT/JP2022/027463, filed on Jul. 12, 2022, which claims priority to Japanese patent application no. 2021-161512, filed on Sep. 30, 2021, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/027463 | Jul 2022 | WO |
| Child | 18442881 | US |
