Battery and vehicle

Abstract

A battery and a vehicle, the battery including a battery module having a battery cell and a cooler having an inlet portion through which a refrigerant flows from the outside, and an outlet portion through which the refrigerant flows to the outside, the battery module being cooled by circulation of the refrigerant inside, the cooler having an inlet-side flow path that communicates with the inlet portion, is provided at a position overlapping a heat generation region, and an outlet-side flow path that communicates with the inlet-side flow path and the outlet portion, is provided at a position overlapping a non-heat generation region.

Description

Technical Field

[0001] This disclosure relates to batteries and vehicles. Background Technology

[0002] Japanese Patent Application Publication No. 2018-538662 discloses a technology that cools the battery cells by installing a cooling supply circulation unit inside a housing that houses a battery cell assembly containing at least one battery cell and has an inlet section on one side for receiving refrigerant that cools the battery cell and an outlet section for receiving refrigerant that exits. In this technology, a refrigerant circulation hole is provided in each of the multiple transverse and longitudinal partitions forming the housing space for housing the battery cell assembly, connecting the inlet section and the outlet section to supply and circulate refrigerant into the housing. Summary of the Invention

[0003] In systems with multiple heat-generating modules, such as battery cell components, and employing refrigerant circulation for cooling using technology similar to that described in Japanese Patent Application Publication No. 2018-538662, the temperature of the refrigerant at the inlet (such as the inlet section) tends to be lower when comparing its temperature with that at the outlet (such as the outlet section). Therefore, in Japanese Patent Application Publication No. 2018-538662, the temperature difference between the battery cell components at the inlet and outlet sides increases. Due to the varying resistance values ​​caused by this temperature difference, current density deviations occur, leading to a localized increase in heat generation and potentially accelerating battery cell degradation.

[0004] This disclosure is made in view of the foregoing, with the aim of providing a battery and vehicle capable of suppressing the aging degradation of battery cells by suppressing the expansion of temperature distribution within the battery cell.

[0005] The battery disclosed herein includes a battery module and a cooler. The battery module has battery cells, and the cooler has an inlet for refrigerant to flow in from the outside and an outlet for refrigerant to flow out from the outside. The battery module is cooled by the refrigerant circulating internally. The battery module has a heated area and a non-heated area. The cooler has an inlet-side flow path and an outlet-side flow path. The inlet-side flow path communicates with the inlet and is located at a position overlapping the heated area. The outlet-side flow path communicates with the inlet-side flow path and the outlet and is located at a position overlapping the non-heated area.

[0006] In addition, the battery module has multiple battery cells stacked on top of each other, and the inlet-side flow path is located at a position that overlaps with the heat-generating area in the stacking direction of the multiple battery cells.

[0007] Therefore, since the inlet-side flow path is located at a position overlapping the heat-generating area in the stacking direction of multiple battery cells, the temperature distribution of the battery module in the stacking direction can be suppressed to the greatest extent.

[0008] Additionally, the battery module includes: a coated area coated with an active material; an uncoated area uncoated with the active material; and a sealing portion disposed to cover the outer periphery of the battery cell. The heat-generating area is the coated area, and the non-heat-generating area is the uncoated area and the sealing portion.

[0009] Therefore, since the inlet-side flow path is located in the coating area of ​​the heat-generating region, it can effectively suppress the temperature distribution of the battery module in the stacking direction.

[0010] In addition, the refrigerant moves from the inlet-side flow path toward the outlet-side flow path.

[0011] Therefore, as the refrigerant moves from the inlet side flow path to the outlet side flow path, the battery module can be effectively cooled.

[0012] In addition, the refrigerant is a liquid.

[0013] Therefore, since the refrigerant is liquid, it can further cool the battery module compared to air cooling.

[0014] Additionally, the vehicle disclosed herein includes a battery comprising a battery module and a cooler. The battery module has battery cells, and the cooler has an inlet for refrigerant to flow in from the outside and an outlet for refrigerant to flow out from the outside. The battery module is cooled by internal circulation of the refrigerant. The battery module has a heated area and a non-heated area. The cooler has an inlet-side flow path and an outlet-side flow path. The inlet-side flow path communicates with the inlet and is located at a position overlapping the heated area. The outlet-side flow path communicates with the inlet-side flow path and the outlet and is located at a position overlapping the non-heated area.

[0015] According to this disclosure, by setting the inlet-side flow path at a position overlapping with the heat-generating area of ​​the battery module and setting the outlet-side flow path at a position overlapping with the non-heat-generating area of ​​the battery module, the expansion of temperature distribution within the battery cell can be suppressed, thus achieving the effect of suppressing the deterioration of the battery cell over the years. Attached Figure Description

[0016] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and wherein:

[0017] Figure 1This is a schematic diagram showing the general configuration of a vehicle equipped with a battery according to one embodiment.

[0018] Figure 2 It is a three-dimensional diagram showing the general structure of a battery.

[0019] Figure 3 From Figure 2 Arrow Z shows the side view of the battery.

[0020] Figure 4 This is a top view of the battery cells in the battery module.

[0021] Figure 5 This refers to the case where a bipolar structure is used in the battery cells of the battery module. Figure 4 A sectional view along line AA.

[0022] Figure 6 This refers to the case where the battery cells in the battery module employ a monopolar structure. Figure 4 A sectional view along line AA.

[0023] Figure 7 It is a three-dimensional diagram that schematically illustrates the flow path of the cooler and the positional relationship of the battery module.

[0024] Figure 8 It is a schematic plan view illustrating the flow path of the cooler.

[0025] Figure 9 This is a schematic diagram showing the relationship between the flow path shape of the cooler (as seen from a perspective view) and the position of the battery module.

[0026] Figure 10 yes Figure 9 A schematic diagram of the temperature image of the battery module at the BB line cross-section.

[0027] Figure 11 It is a graph showing the relationship between temperature and location within the battery cells of a conventional cooler.

[0028] Figure 12 This is a schematic diagram showing the relationship between the state of the flow path shape of the transparent cooler and the position of the battery module.

[0029] Figure 13 yes Figure 12 A schematic diagram of the temperature image of the battery module at the CC line cross-section.

[0030] Figure 14 It is a graph showing the relationship between temperature and location within the battery cells of the cooler. Detailed Implementation

[0031] Hereinafter, a battery module according to one embodiment of the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to the following embodiments. Furthermore, the same reference numerals will be used to refer to the same parts in the following description.

[0032] [General Vehicle Components]

[0033] Figure 1 This is a schematic diagram showing the general configuration of a vehicle equipped with a battery according to one embodiment. Figure 1 The vehicle 1 shown is assumed to be an electric vehicle (EV) or a plug-in hybrid vehicle (PHV) that uses a motor or the like as a power source.

[0034] Vehicle 1 includes a motor 2, a power control unit 3 (hereinafter referred to as "PCU3"), a battery 4, cooling pipes 5, an electric pump 6, a heat exchanger 7, and an ECU (Electronic Control Unit) 8.

[0035] Motor 2 uses electricity from battery 4 to output power for driving. Motor 2 is electrically connected to battery 4 via PCU3. In vehicle 1, the power output from motor 2 is transmitted to drive wheels via a power transmission device.

[0036] PCU3 drives and controls motor 2. PCU3 is configured to include at least a converter for driving motor 2, a boost converter, and a DC / DC converter. For example, in PCU3, the converter converts the DC power from battery 4 into AC power and supplies it to motor 2.

[0037] Battery 4 stores the power supplied to motor 2. Specifically, battery 4 is an energy storage device capable of being charged with power supplied from an external power source. Battery 4 is electrically connected to the charging plug of an external charging device via a charging port (not shown) provided on vehicle 1, and is charged with power supplied from the charging device. Battery 4 is constructed using a module formed by stacking multiple planar units (battery cells) in the vertical direction, and a cooler for cooling the module. Furthermore, the detailed structure of battery 4 will be described later.

[0038] Cooling piping 5 connects battery 4, electric pump 6, and heat exchanger 7 in the flow path, allowing the refrigerant cooling battery 4 to circulate. Here, the refrigerant can be any of air, water, mineral oil, synthetic oil, silicone oil, fluorinated oil, insulating refrigerant (e.g., R134a instead of Freon-based refrigerants), or insulating oil. In one embodiment, the use of water as the refrigerant will be described. Furthermore, cooling piping 5 is constructed from non-conductive or conductive materials. Specifically, cooling piping 5 is constructed from rubber, resin, or aluminum.

[0039] Under the control of ECU8, electric pump 6 circulates the refrigerant in cooling pipe 5. Specifically, electric pump 6 draws in refrigerant stored in the reservoir and discharges it from the outlet toward cooling pipe 5. The refrigerant discharged by electric pump 6 circulates through cooling pipe 5, battery 4, and heat exchanger 7 using the discharge pressure of electric pump 6.

[0040] Under the control of ECU8, heat exchanger 7 dissipates heat from the refrigerant by exchanging heat with the refrigerant circulating in cooling pipe 5. Heat exchanger 7 is constructed using, for example, a radiator and an electric fan.

[0041] ECU8 controls the drive of electric pump 6 and heat exchanger 7. ECU8 is composed of a processor with hardware such as memory and CPU (Central Processing Unit).

[0042] [Detailed Structure of a Battery]

[0043] Next, the detailed structure of battery 4 will be explained. Figure 2 It is a three-dimensional diagram showing the general structure of a battery. Figure 3 From Figure 2 Arrow Z shows the side view of battery 4.

[0044] like Figure 2 and Figure 3 As shown, battery 4 includes multiple battery modules 41 and multiple coolers 42. Specifically, as Figure 2 and Figure 3 As shown, battery 4 is constructed by sequentially stacking a cooler 42, a battery module 41, a cooler 42, another battery module 41, and another cooler 42. Furthermore, in... Figure 2 and Figure 3 In the battery 4 shown, two battery modules 41 are stacked. However, the number of stacked battery modules 41 can be appropriately varied as long as either the upper or lower surface of the battery module 41 contacts the cooler 42. Furthermore, the number of coolers 42 can also be appropriately varied. Additionally, the order of the stacked layers in the battery 4 can, for example, be from bottom to top: battery module 41, cooler 42, battery module 41, battery module 41, cooler 42, and battery module 41 again.

[0045] First, the detailed structure of the battery module 41 will be explained. The battery module 41 is constructed by stacking multiple flat battery cells 410 (see reference). Figure 3 The battery cell 410 of the battery module 41 can be constructed using either a bipolar or unipolar configuration.

[0046] [Bipolar Structure]

[0047] First, the case where the battery cell 410 of the battery module 41 adopts a bipolar structure will be explained. Figure 4 This is a top view of the battery unit 410 of the battery module 41. Figure 5 This is in the case where the battery cell 410 of the battery module 41 adopts a bipolar structure. Figure 4 A sectional view along line AA.

[0048] like Figure 4 and Figure 5 As shown, the bipolar battery cell 410 is configured to sequentially stack the following: a first electrode foil 412, on which a positive electrode active material 411 is coated on the surface side (one side); a separator 413; an intermediate electrode foil 415, on which a negative electrode active material 414 is coated on the back side and a positive electrode active material 411 is coated on the surface side; a separator 413; an intermediate electrode foil 415, on which a negative electrode active material 414 is coated on the back side and a positive electrode active material 411 is coated on the surface side; a separator 413; and a second electrode foil 416, on which a negative electrode active material 414 is coated on the back side (one side). Furthermore, in Figure 5 In this battery cell, the intermediate electrode foil 415 has two layers, but any number of spacers 413 and intermediate electrode foils 415 can be stacked between the first electrode foil 412 and the second electrode foil 416. Furthermore, the first electrode foil 412, the intermediate electrode foil 415, and the second electrode foil 416 are each made of aluminum or the like. Moreover, the battery cell 410 has a sealing portion 417 formed of resin or the like to protect the outer periphery.

[0049] Furthermore, in the battery cell 410, the area where the positive electrode active material 411 and the negative electrode active material 414 are respectively present in the first electrode foil 412, the intermediate electrode foil 415, and the second electrode foil 416 becomes the heat-generating region W1. Moreover, in the battery cell 410, the area containing the uncoated active material area (where the positive electrode active material 411 and the negative electrode active material 414 are not coated) and the area containing the sealing portion 417 becomes the non-heat-generating region W2.

[0050] [Monopolar Structure]

[0051] Next, the case where the battery cell 410 of the battery module 41 adopts a unipolar structure will be explained. Figure 6 This is in the case where the battery cell 410 of the battery module 41 adopts a unipolar structure. Figure 4 A sectional view along line AA.

[0052] like Figure 4 and Figure 6As shown, the unipolar battery cell 410A is constructed by stacking multiple sets of a first electrode foil 412, on the surface side (one side) coated with a positive electrode active material 411, a spacer 413, and a second electrode foil 418, on the back side coated with a negative electrode active material 414, as a set of layers. The first electrode foil 412 is made of aluminum or the like. The second electrode foil 418 is made of copper or the like. Furthermore, the battery module 41 has a sealing portion 417 formed of resin or the like to protect the outer peripheral side.

[0053] Furthermore, in battery cell 410A, the areas where the positive electrode active material 411 and the negative electrode active material 414 are respectively present in the first electrode foil 412 and the second electrode foil 418 are respectively called the heat-generating area W1. Moreover, in battery cell 410A, the area of ​​uncoated active material including the area where the positive electrode active material 411 and the negative electrode active material 414 are not coated and the area of ​​the sealing part 417 are called the non-heat-generating area W2.

[0054] [Construction of the cooler]

[0055] Next, the construction of the cooler 42 will be described in detail. Figure 7 This is a perspective view that schematically illustrates the flow path of the cooler 42 and the positional relationship of the battery module 41. Figure 8 This is a schematic plan view illustrating the flow path of the cooler 42. Furthermore, in Figure 7 and Figure 8 In the diagram, arrows indicate the flow of refrigerant.

[0056] like Figure 7 and Figure 8 As shown, the cooler 42 has an inlet 421 for supplying refrigerant Wa from the electric pump 6 via a cooling pipe 5, and an outlet 422 for discharging refrigerant Wa into the cooling pipe 5. Furthermore, the cooler 42 has an inlet-side flow path 423 connected to the inlet 421 and positioned overlapping the heat-generating region W1, and an outlet-side flow path 424 connected to both the inlet-side flow path 423 and the outlet 422 and positioned overlapping the non-heat-generating region W2. The cooler 42 is constructed using a conductive component (e.g., aluminum).

[0057] In the cooler 42 configured in this way, the battery module 41 is cooled by the refrigerant Wa flowing in from the inlet 421 circulating through the internal flow path. Moreover, the coolers 42 located at the bottom and top layers function as electrodes of the battery 4 by being electrically connected to each layer.

[0058] [Cooling effect of the cooler on the battery module]

[0059] Next, the cooling effect of the cooler 42 on the battery module 41 will be explained. After explaining the cooling effect of a conventional cooler on the battery module 41, the cooling effect of the cooler 42 according to one embodiment on the battery module 41 will be explained. Furthermore, in the following description, temperature is indicated by shading; the denser the shading, the higher the temperature.

[0060] First, let's explain the previous technologies. Figure 9 This is a schematic diagram showing the relationship between the current state of the cooler's flow path shape as seen from a perspective and the position of the battery module 41. Figure 10 yes Figure 9 A schematic diagram of the temperature image of battery module 41 in the BB line cross section. Figure 11 This is a graph showing the temperature and positional relationship within the battery cell 410 based on a conventional cooler. Figure 11 In the diagram, straight line L1 represents the temperature and position relationship of battery cell C in battery module 41, and straight line L2 represents the temperature and position relationship of battery cell B in battery module 41.

[0061] like Figures 9-11 As shown, in the conventional cooler 100, the inlet-side flow path 102 is located in the non-heating area of ​​the battery module 41, and the outlet-side flow path 103 is located in the non-heating area of ​​the battery module 41 (see reference). Figure 4 Therefore, in the conventional cooler 100, the temperature difference D1 within the battery cell C is small (refer to...). Figure 11 The straight line L1), but a large temperature difference D2 will occur between the inlet and outlet sides of battery cell B (refer to the straight line L1). Figure 11 (The straight line L2). That is, in the conventional cooler 100, because the inlet-side flow path receives less heat, the end-side temperature of the battery cell B does not rise sufficiently. Therefore, in the conventional cooler 100, the temperature difference within the battery cell B increases, resulting in a deviation in current density and a local increase in heat generation, which may promote degradation.

[0062] Next, the cooling effect of cooler 42 on battery module 41 will be explained. Figure 12 This is a schematic diagram showing the relationship between the flow path shape of the transparent cooler 42 and the position of the battery module 41. Figure 13 yes Figure 12 A schematic diagram of the temperature image of battery module 41 in the CC line cross section. Figure 14 This is a graph showing the temperature and positional relationship within battery cell 410. Figure 14 In the diagram, line L11 represents the temperature and position relationship of battery cell B in battery module 41, and line L12 represents the temperature and position relationship of battery cell C in battery module 41.

[0063] like Figures 12-14As shown, in the cooler 42, the inlet-side flow path 423 is positioned overlapping the heat-generating region W1, and the outlet-side flow path 424 is positioned overlapping the non-heat-generating region W2. Therefore, the cooler 42 can reduce the intra-cell temperature difference D11 (straight line L11) of battery cell C and the intra-cell temperature difference D12 (straight line L12) of battery cell B on the inlet and outlet sides. As a result, the cooler 42 can effectively suppress the temperature distribution of the battery module 41 in the stacking direction, without excessively lowering the temperature of the low-temperature portions of the battery cells 410 far from the cooler 42. Therefore, it can prevent deviations in current density and prevent the degradation of the battery module 41.

[0064] According to the embodiment described above, by setting the inlet-side flow path 423 at a position overlapping with the heat-generating area W1 of the battery module 41 and setting the outlet-side flow path 424 at a position overlapping with the non-heat-generating area W2 of the battery module 41, the expansion of temperature distribution within the battery cell 410 can be suppressed, thus suppressing the deterioration of the battery cell 410 over the years.

[0065] In addition, according to one embodiment, the inlet side flow path 423 is provided at a position overlapping the heat generation area W1 in the stacking direction of the stacked multiple battery cells 410, so that in addition to the battery cells C directly stacked on the cooler 42, the temperature distribution of the battery module 41 in the stacking direction can be suppressed as much as possible.

[0066] In addition, according to one embodiment, the inlet-side flow path 423 is provided in the uncoated area of ​​the heat-generating area W1, so the expansion of the temperature distribution of the battery cell B can be suppressed as much as possible.

[0067] In addition, according to one embodiment, the refrigerant Wa moves from the inlet-side flow path 423 toward the outlet-side flow path 424, so the battery module 41 can be effectively cooled.

[0068] In addition, according to one embodiment, the refrigerant Wa is a liquid, so it can further cool the battery module 41 compared to air cooling.

[0069] (Modified Example)

[0070] Furthermore, in one embodiment, the inlet-side flow path 423 and outlet-side flow path 424 of the plurality of coolers 42 stacked in the battery 4 are each arranged in parallel in the stacking direction, but are not limited thereto. For example, the inlet-side flow path 423 and outlet-side flow path 424 may also be stacked orthogonally in each stacking of the coolers 42.

[0071] (Other implementation methods)

[0072] Further effects and variations can be readily derived by those skilled in the art. The broader scope of the invention is not limited to the specific, detailed, and representative embodiments shown and described above. Therefore, various modifications can be made without departing from the spirit or scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A type of battery, The battery comprises multiple battery modules and multiple coolers, wherein the multiple coolers and multiple battery modules are stacked sequentially such that both the upper and lower surfaces of the battery modules are in contact with the coolers. The battery module has battery cells. The battery module includes: a coated area coated with an active material; an uncoated area without the active material; and a sealing portion disposed to cover the outer periphery of the battery cell. The battery module has a heated area and a non-heated area. The heated area is the coated area, and the non-heated area consists of the uncoated area and the sealing portion. The cooler has an inlet for refrigerant to flow in from the outside and an outlet for refrigerant to flow out from the outside, cooling the battery module by circulating the refrigerant internally. The cooler has an inlet-side flow path and an outlet-side flow path. The inlet-side flow path is connected to the inlet section and is located at a position overlapping with the heating area. The outlet-side flow path is connected to the inlet-side flow path and the outlet section, and is located at a position overlapping with the non-heating area. The inlet-side flow path has multiple flow paths that extend from the heated area toward the non-heated area and are connected to the outlet-side flow path.

2. The battery according to claim 1, The battery module has multiple battery cells stacked on top of each other. The inlet-side flow path is located at a position overlapping the heat-generating area in the stacking direction of the multiple battery cells.

3. The battery according to claim 1 or 2, The refrigerant moves from the inlet-side flow path toward the outlet-side flow path.

4. The battery according to claim 1 or 2, The refrigerant is a liquid.

5. A type of vehicle, The battery comprising any one of claims 1 to 4.

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