Patent Application
20220367922
The present application relates to a secondary battery, an electronic device, and a power tool.
Lithium ion batteries have been developed for applications requiring high output such as power tools and electric vehicles. Examples of one method for achieving high output include high rate discharge in which a relatively large current flows from a battery. In the lithium ion battery, not limited to the lithium ion battery for high rate discharge, deformation of the electrode during charging and discharging has a problem of shortening the life of the battery.
For example, a battery is described in which the number of idling windings of a separator is increased or an inert material is wound together with the separator at the start of winding, thereby improving deformation resistance of a central portion due to electrode expansion and increasing the cycle life.
The present application relates to a secondary battery, an electronic device, and a power tool.
The battery described in the BACKGROUND section relates to a normal battery using a lead as an extraction electrode, and when this technique is directly applied to the battery for high rate discharge, there is a problem that a bent active material non-covered portion may enter an inner peripheral portion, break the separator, and cause an internal short circuit.
Therefore, the present application relates to providing a battery for high rate discharge that does not cause an internal short circuit according to an embodiment.
In order to solve the above-described problems, the present application, in an embodiment, provides a secondary battery in which an electrode winding body having a structure in which a strip-shaped positive electrode and a strip-shaped negative electrode are stacked with a separator interposed therebetween and wound around a central axis, a positive electrode current collector plate, and a negative electrode current collector plate are housed in a battery can,
the positive electrode having a positive electrode active material covered portion covered with a positive electrode active material layer and a positive electrode active material non-covered portion on a strip-shaped positive electrode foil,
the negative electrode having a negative electrode active material covered portion covered with a negative electrode active material layer and a negative electrode active material non-covered portion on a strip-shaped negative electrode foil,
the positive electrode active material non-covered portion being joined to the positive electrode current collector plate at one end portion of the electrode winding body,
the negative electrode active material non-covered portion being joined to the negative electrode current collector plate at the other end portion of the electrode winding body,
the electrode winding body having a flat surface formed by bending at least the positive electrode active material non-covered portion toward a central axis of the wound structure and overlapping each other, a groove formed in the flat surface, and an inner peripheral portion located inside innermost peripheries of the positive electrode and the negative electrode and including only the separator,
a length E of a portion where the positive electrode active material non-covered portion protrudes from one end of the separator in a width direction being larger than a length F of a portion where the separator protrudes from one end of the negative electrode in the width direction, and
when the number of layers of the separator in the inner peripheral portion is m, a thickness is t, and Z=t×m, Formula (1) being satisfied:
80≤Z≤196. Formula (1):
According to an embodiment, it is possible to provide a battery in which an internal short circuit and a welding failure do not occur and an initial capacity can be kept high. The contents of the present application should not be interpreted as being limited by the effects exemplified herein.
Hereinafter, the present application will be described in further detail including with reference to the drawings according to an embodiment.
The present application described herein includes examples, without limitation, according to an embodiment.
In an embodiment, a cylindrical lithium ion battery will be described as an example of the secondary battery.
First, a whole configuration of the lithium ion battery will be described.
Specifically, the lithium ion battery 1 includes, for example, a pair of insulating plates 12 and 13 and the electrode winding body 20 inside the cylindrical battery can 11. However, the lithium ion battery 1 may further include, for example, one or two or more of a positive temperature coefficient (PTC) element, a reinforcing member, and the like inside the battery can 11.
The battery can 11 is a member that mainly houses the electrode winding body 20. The battery can 11 is, for example, a cylindrical vessel having one end surface opened and the other end surface closed. That is, the battery can 11 has an open end surface (open end surface 11N). The battery can 11 contains, for example, one or two or more of metal materials such as iron, aluminum and their alloys. However, one or two or more of metal materials such as nickel may be plated on the surface of the battery can 11, for example.
The insulating plates 12 and 13 are dish-shaped plates having a surface substantially perpendicular to a winding axis (Z axis in
At the open end surface 11N of the battery can 11, the battery lid 14 and the safety valve mechanism 30 are crimped with the gasket 15 interposed therebetween, and a crimped structure 11R (crimped structure) is formed. Consequently, the battery can 11 is hermetically sealed in a state in which the electrode winding body 20 and the like are housed inside the battery can 11.
The battery lid 14 is a member that mainly closes the open end surface 11N of the battery can 11 in the state in which the electrode winding body 20 and the like are housed inside the battery can 11. The battery lid 14 contains, for example, a material similar to a material for forming the battery can 11. A central region of the battery lid 14 protrudes, for example, in a +Z direction. Thus, a region (peripheral region) other than the central region of the battery lid 14 is in contact with, for example, the safety valve mechanism 30.
The gasket 15 is a member that mainly seals a gap between the bent portion 11P and the battery lid 14 by being interposed between the battery can 11 (bent portion 11P) and the battery lid 14. However, a surface of the gasket 15 may be coated with asphalt or the like, for example.
The gasket 15 contains, for example, one or two or more of insulating materials. The type of insulating material is not particularly limited, and is, for example, a polymeric material such as polybutylene terephthalate (PBT) and polypropylene (PP). Particularly, the insulating material is preferably polybutylene terephthalate. This is because the gap between the bent portion 11P and the battery lid 14 is sufficiently sealed while the battery can 11 and the battery lid 14 are electrically separated from each other.
When pressure (internal pressure) inside the battery can 11 rises, the safety valve mechanism 30 mainly releases the internal pressure by releasing the hermetically sealed state of the battery can 11 as necessary. The cause of the increase in the internal pressure of the battery can 11 is, for example, a gas generated due to a decomposition reaction of an electrolytic solution during charge and discharge.
In the cylindrical lithium ion battery, a strip-shaped positive electrode 21 and a strip-shaped negative electrode 22 are spirally wound with the separator 23 interposed therebetween, and are accommodated in the battery can 11 in a state of being impregnated with the electrolytic solution. The positive electrode 21 is obtained by forming a positive electrode active material layer on one surface or both surfaces of a positive electrode foil 21A, and a material of the positive electrode foil 21A is, for example, a metal foil made of aluminum or an aluminum alloy. The negative electrode 22 is obtained by forming a negative electrode active material layer on one surface or both surfaces of a negative electrode foil 22A, and a material of the negative electrode foil 22A is, for example, a metal foil made of nickel, a nickel alloy, copper, or a copper alloy. The separator 23 is a porous and insulating film, and enables movement of substances such as ions and an electrolytic solution while electrically insulating the positive electrode 21 and the negative electrode 22.
Although the positive electrode active material layer and the negative electrode active material layer cover many portions of the positive electrode foil 21A and the negative electrode foil 22A, respectively, neither of the active material layers intentionally covers a periphery of one end in a transverse direction of the strip. Hereinafter, the portions not covered with the active material layer will be appropriately referred to as active material non-covered portions 21C and 22C, and the portions covered with the active material layer will be appropriately referred to as active material covered portions 21B and 22B. In the cylindrical battery, the electrode winding body 20 is wound in such a manner that an active material non-covered portion 21C of the positive electrode and an active material non-covered portion 22C of the negative electrode are overlapped each other with the separator 23 interposed therebetween so as to face in opposite directions.
The active material non-covered portion 21C of the positive electrode is formed from, for example, aluminum and the like, and the active material non-covered portion 22C of the negative electrode is formed from, for example, copper and the like; therefore, in general, the active material non-covered portion 21C of the positive electrode is softer (has a lower Young's modulus) than the active material non-covered portion 22C of the negative electrode. Thus, in one embodiment, A>B and C>D are more preferable, and in this case, when the active material non-covered portion 21C of the positive electrode and the active material non-covered portion 22C of the negative electrode are simultaneously bent at the same pressure from both electrode sides, a height of the bent portion measured from a tip of the separator 23 may be substantially the same between the positive electrode 21 and the negative electrode 22. At this time, since the active material non-covered portions 21C and 22C are bent and suitably overlap each other, the active material non-covered portions 21C and 22C and current collector plates 24 and 25 can be easily joined by laser welding. Although joining in one embodiment means joining by laser welding, the joining method is not limited to laser welding.
In the positive electrode 21, a section having a width of 3 mm and including a boundary between the active material non-covered portion 21C and the active material covered portion 21B is covered with an insulating layer 101 (gray region portion in
A through hole 26 is formed in a region including a central axis of the electrode winding body 20. The through hole 26 is a hole into which a winding core for assembling the electrode winding body 20 and an electrode rod for welding are inserted. Since the electrode winding body 20 is wound in an overlapping manner such that the active material non-covered portion 21C of the positive electrode and the active material non-covered portion 22C of the negative electrode face in opposite directions, the active material non-covered portion 21C of the positive electrode gathers on one end surface (end surface 41) of the electrode winding body, and the active material non-covered portion 22C of the negative electrode gathers on the other end surface (end surface 42) of the electrode winding body 20. In order to improve contact with the current collector plates 24 and 25 for extracting current, the active material non-covered portions 21C and 22C are bent, and the end surfaces 41 and 42 are flat surfaces. The bending direction is a direction from outer edge portions 27 and 28 of the end surfaces 41 and 42 toward the through hole 26, and the active material non-covered portions of adjacent peripheries overlap each other and are bent in a wound state. In the present specification, the “flat surface” includes not only an absolutely flat surface but also a surface having some unevenness and surface roughness to the extent that the active material non-covered portion and the current collector plate can be joined.
When the active material non-covered portions 21C and 22C are bent so as to overlap each other, at first it appears that the end surfaces 41 and 42 can be made flat; however, if no processing is performed before bending, wrinkles or voids (spaces) are generated in the end surfaces 41 and 42 at the time of bending, and the end surfaces 41 and 42 do not become flat surfaces. Here, “wrinkles” and “voids” are portions where unevenness occurs in the bent active material non-covered portions 21C and 22C, and the end surfaces 41 and 42 do not become flat surfaces. In order to prevent the occurrence of wrinkles and voids, a groove 43 (see, for example,
A detailed configuration of the electrode winding body 20, that is, detailed configurations of the positive electrode 21, the negative electrode 22, the separator 23, and the electrolytic solution will be described later.
In a normal lithium ion battery, for example, a lead for current extraction is welded to each one portion of the positive electrode and the negative electrode; however, this is not suitable for high rate discharge because the internal resistance of the battery is large, and the lithium ion battery generates heat and becomes high temperature during discharge. Thus, in the lithium ion battery of one embodiment, the positive electrode current collector plate 24 and the negative electrode current collector plate 25 are arranged on the end surfaces 41 and 42, and are welded to the active material non-covered portions 21C and 22C of the positive electrode and the negative electrode present on the end surfaces 41 and 42 at multiple points, thereby suppressing the internal resistance of the battery to be low. The end surfaces 41 and 42 being bent to be flat surfaces also contributes to the reduction in resistance.
A portion indicated by dots in
The negative electrode current collector plate 25 has substantially the same shape as the positive electrode current collector plate 24, but has a different strip-shaped portion. The strip-shaped portion 34 of the negative electrode current collector plate in
The positive electrode active material layer contains at least a positive electrode material (positive electrode active material) capable of occluding and releasing lithium, and may further contain a positive electrode binder, a positive electrode conductive agent, and the like. The positive electrode material is preferably a lithium-containing composite oxide or a lithium-containing phosphate compound. The lithium-containing composite oxide has, for example, a layered rock salt-type or spinel-type crystal structure. The lithium-containing phosphate compound has, for example, an olivine type crystal structure.
The positive electrode binder contains synthetic rubber or a polymer compound. The synthetic rubber includes styrene-butadiene-based rubber, fluororubber, ethylene propylene diene, and the like. The polymer compounds includes polyvinylidene fluoride (PVdF), polyimide, and the like.
The positive electrode conductive agent is a carbon material such as graphite, carbon black, acetylene black, or Ketjen black. However, the positive electrode conductive agent may be a metal material and a conductive polymer.
The thickness of the positive electrode foil 21A is preferably 5 μm or more and 20 μm or less. This is because, if the thickness of the positive electrode foil 21A is 5 μm or more, the positive electrode 21 can be produced without being broken when the positive electrode 21, the negative electrode 22, and the separator 23 are wound in an overlapping manner. This is because, when the thickness of the positive electrode foil 21A is 20 μm or less, a decrease in energy density of the battery 1 can be prevented, and a facing area between the positive electrode 21 and the negative electrode 22 increases, so that the battery 1 having a large output can be obtained.
A surface of the negative electrode foil 22A is preferably roughened for improving close-contact characteristics with the negative electrode active material layer. The negative electrode active material layer contains at least a negative electrode material (negative electrode active material) capable of occluding and releasing lithium, and may further contain a negative electrode binder, a negative electrode conductive agent, and the like.
The negative electrode material contains, for example, a carbon material. The carbon material is easily graphitizable carbon, non-graphitizable carbon, graphite, low crystalline carbon, or amorphous carbon. The shape of the carbon material is fibrous, spherical, granular, or scaly.
The negative electrode material contains, for example, a metal-based material. Examples of the metal-based material include Li (lithium), Si (silicon), Sn (tin), Al (aluminum), Zr (zinc), and Ti (titanium). The metal-based element forms a compound, a mixture, or an alloy with another element, and examples thereof include silicon oxide (SiOx (0<x≤2)), silicon carbide (SiC), an alloy of carbon and silicon, and lithium titanate (LTO).
The thickness of the negative electrode foil 22A is preferably 5 μm or more and 20 μm or less. This is because, if the thickness of the negative electrode foil 22A is 5 μm or more, the negative electrode 22 can be produced without being broken when the positive electrode 21, the negative electrode 22, and the separator 23 are wound in an overlapping manner. This is because, when the thickness of the negative electrode foil 22A is 20 μm or less, the decrease in energy density of the battery 1 can be prevented, and the facing area between the positive electrode 21 and the negative electrode 22 increases, so that the battery 1 having a large output can be obtained.
The separator 23 is a porous film containing a resin, and may be a stacked film of two or more kinds of porous films. Examples of the resin include polypropylene and polyethylene. The separator 23 may include a resin layer on one side or both sides of a porous membrane as a substrate layer. The reason for this is that, this allows for an improvement in close-contact characteristics of the separator 23 with respect to each of the positive electrode 21 and the negative electrode 22, thereby suppressing distortion of the electrode winding body 20.
The resin layer contains a resin such as PVdF. When the resin layer is formed, the base material layer is coated with a solution prepared by dissolving the resin in an organic solvent, and thereafter, the substrate layer is dried. Alternatively, the base material layer may be immersed in the solution, and thereafter the substrate layer may be dried. The resin layer preferably contains inorganic particles or organic particles from the viewpoint of improving heat resistance and safety of the battery. The type of the inorganic particles is aluminum oxide, aluminum nitride, aluminum hydroxide, magnesium hydroxide, boehmite, talc, silica, mica, or the like. In place of the resin layer, a surface layer formed by a sputtering method, an ALD (atomic layer deposition) method, and other methods and mainly composed of inorganic particles may be used.
The thickness of the separator 23 is preferably 4 μm or more and 30 μm or less. When the thickness of the separator is 4 μm or more, it is possible to prevent an internal short circuit due to contact between the positive electrode 21 and the negative electrode 22 facing each other with the separator 23 interposed therebetween. When the thickness of the separator 23 is 30 μm or less, lithium ions and an electrolytic solution can easily pass through the separator 23, and during winding, an electrode density of the positive electrode 21 and the negative electrode 22 can be increased.
The electrolytic solution contains a solvent and an electrolyte salt, and may further contain an additive and the like as necessary. The solvent is a non-aqueous solvent such as an organic solvent, or water. An electrolytic solution containing a non-aqueous solvent is referred to as a non-aqueous electrolytic solution. The non-aqueous solvent is a cyclic carbonate ester, a chain carbonate ester, lactone, a chain carboxylic ester, or nitrile (mononitrile).
Although a representative example of the electrolyte salt is a lithium salt, a salt other than the lithium salt may be contained. Examples of the lithium salt include lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium methanesulfonate (LiCH3SO3), lithium trifluoromethanesulfonate (LiCF3SO3), and dilithium hexafluorosilicate (Li2SF6). These salts may be used in mixture, and among them, it is preferable to use LiPF6 and LiBF4 in mixture from the viewpoint of improving battery characteristics. The content of the electrolyte salt is not particularly limited, and is preferably from 0.3 mol/kg to 3 mol/kg with respect to the solvent.
A method for producing the lithium ion battery 1 of one embodiment will be described with reference to
Next, as shown in
Thereafter, as shown in
Hereinafter, the present application will be described based on Examples in which an open circuit voltage failure rate, an initial capacity, and a welding failure rate are compared using the lithium ion battery 1 produced as described above according to an embodiment. The present application is not limited to Examples described below.
In all of the following Examples and Comparative Examples, a battery size was set to 21700 (diameter: 21 mm, height: 70 mm), and the separator 23 was overlapped so as to cover the entire range of the active material covered portion 21B of the positive electrode and the active material covered portion 22B of the negative electrode.
The thickness of the separator 23 was defined as t, a plurality of layers of the separators 23 were arranged at the inner peripheral portion of the electrode winding body 20, the number of layers of the separator 23 at the inner peripheral portion was defined as m, and Z=t×m. Here, as shown in
The number of the grooves 43 was eight, and the grooves were arranged at substantially equal angular intervals. A distance between the active material non-covered portions 21C of the adjacent positive electrodes and a distance between the active material non-covered portions 22C of the adjacent negative electrodes were 0.2 mm. In Examples and Comparative Examples other than Comparative Example 3, a structure in which the active material non-covered portions 21C of the positive electrode overlapped each other was adopted, and in Comparative Example 3, a structure in which the active material non-covered portions 21C of the positive electrode did not overlap was adopted.
As shown in
As shown in
As shown in
As shown in
The open circuit voltage failure rate, the initial capacity, and the welding failure rate were determined for the batteries 1 of Example 1 and Comparative Examples 1 to 3. In the open circuit voltage failure rate, when constant current-constant voltage charging was performed at 500 mA at an environmental temperature of 25° C., the voltage of the battery 1 immediately after reaching 4.2 V (within 1 hour) was V1, the battery 1 was left to stand thereafter, and the voltage of the battery 1 after two weeks was V2, the battery 1 in which V1−V2≥50 mV was determined as an open circuit voltage failure, and the number of the batteries 1 was counted to obtain a ratio with respect to the whole. Regarding the initial capacity, constant current discharge is performed at a current value of 500 mA until the voltage reaches 3 V for the battery 1 without the open circuit voltage defect, the initial capacity was a value obtained as a product of the discharged current value at that time and time, and the value of Example 1 was set to 100%. The welding failure rate is obtained by performing laser welding between the positive electrode current collector plate 24 and the active material non-covered portion 21C of the positive electrode, counting the number of batteries in which welding failures such as perforation and sputtering occur, and determining the ratio with respect to the whole. The number of tests was 25 for each example. The results are shown in Table 1.
In Example 1, the open circuit voltage failure rate was as low as 0%, and the welding failure rate was as low as 0%. This was considered to be because, as shown in
In Comparative Example 3, the open circuit voltage failure rate was relatively high. This was considered to be because, as shown in
Next, for the battery of Example 1, a possible range of the value Z was examined by changing the value t and the value m.
E=4.5 mm, F=1 mm, and E>F. When the active material non-covered portion 21C of the positive electrode was bent, the active material non-covered portions 21C of the positive electrode overlapped each other. t=10 μm, m=8, and Z=80.
The example was performed in the same manner as in Example 2, except that t=8 μm, m=10, and Z=80.
The example was performed in the same manner as in Example 2, except that t=14 μm, m=14, and Z=196.
The example was performed in the same manner as in Example 2, except that t=8 μm, m=8, and Z=64.
The example was performed in the same manner as in Example 2, except that t=12 μm, m=6, and Z=72.
The example was performed in the same manner as in Example 2, except that t=20 μm, m=10, and Z=200.
For the batteries 1 of Examples 2 to 4 and Comparative Examples 4 to 6, the open circuit voltage failure rate, the initial capacity, and the welding failure rate were determined in the same manner as described above. Similarly, the number of tests was 25 for each example. The results are shown in Table 2.
In Examples 2 to 4, the open circuit voltage failure rate was as low as 0%, the initial capacity was as high as 100%, and the welding failure rate was as low as 0%, whereas in Comparative Examples 4 to 6, the initial capacity was as high as 100%, and the welding failure rate was as low as 0%; however, the open circuit voltage failure rate was as relatively high as 4% or more. At this time, the range of Z in Examples 2 to 4 was 80 or more and 196 or less.
From Table 2, it can be determined that when 80≤Z≤196, in the battery 1, no internal short circuit occurs, no welding failure occurs, and the initial capacity can be kept high.
The present application has been described herein according to an embodiment; however, the contents of the present application are not limited thereto, and various modifications according to an embodiment.
In Examples and Comparative Examples, the number of the grooves 43 was set to 8, but other numbers may be used. The battery size is 21700 (diameter: 21 mm, height: 70 mm), but may be 18650 (diameter: 18 mm, height: 65 mm) or another size.
The positive electrode current collector plate 24 and the negative electrode current collector plate 25 include the plate-shaped portions 31 and 33 having a fan shape, but may have other shapes.
The present application can also be applied to other batteries other than the lithium ion battery and batteries having a shape other than a cylindrical shape (for example, a laminate-type battery, a square-type battery, a coin-type battery, and a button-type battery). In this case, the shape of the “end surface of the electrode winding body” may be not only a cylindrical shape but also an elliptical shape, a flat shape, or the like.
The assembled battery 301 is formed by connecting a plurality of secondary batteries 301a to each other in series and/or in parallel.
The temperature detector 318 is connected to a temperature detection element 308 (for example, a thermistor), measures the temperature of the assembled battery 301 or the battery pack 300, and supplies the measured temperature to the controller 310. A voltage detector 311 measures the voltage of the assembled battery 301 and the respective secondary batteries 301a configuring the assembled battery and performs A/D conversion of this measured voltage to supply the resulting voltage to the controller 310. A current measurer 313 measures the current by using the current detection resistor 307 and supplies this measured current to the controller 310.
A switch controller 314 controls the charge control switch 302a and the discharge control switch 303a of the switch section 304 based on the voltage and the current input from the voltage detector 311 and the current measurer 313. The switch controller 314 prevents overcharge and overdischarge by sending an OFF control signal to the switch section 304 when the voltage of the secondary battery 301a has become equal to or higher than an overcharge detection voltage (for example, 4.20 V±0.05 V) or equal to or lower than an overdischarge detection voltage (2.4 V±0.1 V).
After the charge control switch 302a or the discharge control switch 303a is turned off, charging or discharging can be performed only through a diode 302b or a diode 303b. As these charge/discharge switches, a semiconductor switch such as a MOSFET can be used. In
The memory 317 includes a RAM and a ROM, and stores and rewrites a value of the battery characteristics calculated by the controller 310, a full charge capacity, the remaining capacity, and the like.
The battery 1 is mounted on a device such as an electronic device, an electric transportation device, or a power storage device, and can be used for supplying electric power according to an embodiment.
Examples of the electronic device include notebook personal computers, smartphones, tablet terminals, PDAs (personal digital assistants), mobile phones, wearable terminals, digital still cameras, electronic books, music players, game machines, hearing aids, power tools, televisions, lighting devices, toys, medical devices, and robots. In addition, electric transportation devices, power storage devices, power tools, and electric unmanned aerial vehicles to be described later can also be included in the electronic device in a broad sense.
Examples of the electric transportation device include electric vehicles (including hybrid vehicles), electric motorcycles, electric assisted bicycles, electric buses, electric carts, automatic guided vehicles (AGV), and railway vehicles. In addition, electric passenger aircrafts and electric unmanned aircrafts for transportation are also included. The secondary battery according to the present application is used not only as these driving power supplies but also as an auxiliary power supply, a power supply for recovering a regenerated energy, and other power supplies.
Examples of the power storage device include power storage modules for commercial use or household use, and power supplies for electric power storage use for a building such as a house, a building, or an office, or for a power-generating facility.
An example of an electric driver as a power tool to which the present application 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 shown) 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 at the time of abnormality such as overdischarge.
As an example in which the present application is applied to an electric vehicle power storage system,
An engine 601, a generator 602, an electric power driving force converter 603 (DC motor or AC motor, hereinafter, it is simply referred to as the “motor 603”), a driving wheel 604a, a driving 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 in a hybrid vehicle 600 as described above. As the battery 608, the battery pack 300 or a power storage module on which a plurality of the batteries 1 are mounted can be applied according to an embodiment.
The motor 603 is operated by the electric power of the battery 608, and a rotating 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 rotating force generated by the engine 601. The various sensors 610 control an engine speed through the vehicle control device 609, or control an opening degree of a throttle valve (not shown).
When the hybrid vehicle 600 is decelerated by a brake mechanism (not shown), a resistance force during the deceleration is added as a rotating force to the motor 603, and regenerative electric power generated due to this rotating force is stored in the battery 608. The battery 608 can be charged by being connected to an external power supply via 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).
The secondary battery can also be applied to a downsized primary battery and used as a power supply of a tire pressure monitoring system (TPMS) built in wheels 604 and 605 according to an embodiment.
Although a 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 in which a series system and a parallel system are combined. In addition, the present application is also applicable to an electric vehicle (EV or BEV) and a fuel cell vehicle (FCV) that travel only by a drive motor not using an engine.
It should be understood that various changes and modifications to the presently preferred 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 |
|---|---|---|---|
| 2020-039147 | Mar 2020 | JP | national |
The present application is a continuation of PCT application no. PCT/JP2021/007248, filed Feb. 26, 2021, which claims priority to Japanese application no. JP2020-039147, filed Mar. 6, 2020, the entire contents of which are being incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2021/007248 | Feb 2021 | US |
| Child | 17876901 | US |
