Cooling and heating the corners of a battery pack

Abstract

A battery pack includes prismatic battery cells arranged in two rectilinear rows; a cooling plate arranged vertically below the battery cells; a heat transfer material arranged between the battery cells and the cooling plate; a thermal insulation material arranged at vertical lower ends of a rectilinear space between the two rectilinear rows of battery cells; a first cooling fluid channel configured to receive a cooling fluid and extending rectilinearly toward the rectilinear space and arranged vertically above the thermal insulation material; a second cooling fluid channel configured to receive the cooling fluid and extending rectilinearly toward the rectilinear space and parallel to the first cooling fluid channel and arranged vertically above the thermal insulation material.

Description

INTRODUCTION

[0001] The present disclosure relates to energy storage devices and, more particularly, to a battery pack that can be selectively heated and cooled.

[0002] For general background information, please refer to the publication DE 10 2015 113 622 A1.

[0003] Some types of vehicles contain only an internal combustion engine that generates drive torque. Electric vehicles do not require an internal combustion engine and can rely on one or more electric motors for propulsion.

[0004] Hybrid vehicles contain both an internal combustion engine and one or more electric motors. Some types of hybrid vehicles use the electric motor and internal combustion engine in an effort to achieve greater fuel efficiency than would be achieved using only the internal combustion engine. Some types of hybrid vehicles use the electric motor and internal combustion engine in an effort to achieve greater torque output than the internal combustion engine alone could achieve.

[0005] Some example types of hybrid vehicles include parallel hybrid vehicles, series hybrid vehicles, and other types of hybrid vehicles. In a parallel hybrid vehicle, the electric motor operates in parallel with the prime mover to combine the power and range advantages of the prime mover with the efficiency and regenerative braking benefits of electric motors. In a series hybrid vehicle, the prime mover drives a generator to produce electricity for the electric motor, and the electric motor drives a transmission. This allows the electric motor to assume some of the power responsibilities from the prime mover, which can permit the use of a smaller and potentially more efficient prime mover. SUMMARY

[0006] According to the invention, a battery pack is presented which is characterized by the features of claim 1.

[0007] The battery pack includes prismatic battery cells arranged in two rectilinear rows; a cooling plate arranged vertically below the battery cells; a heat transfer material arranged between the battery cells and the cooling plate; a thermal insulation material arranged at vertical lower ends of a rectilinear space between the two rectilinear rows of battery cells; a first cooling fluid channel configured to receive a cooling fluid, which runs rectilinearly toward the rectilinear space and is arranged vertically above the thermal insulation material; a second cooling fluid channel configured to receive the cooling fluid, which runs rectilinearly toward the rectilinear space and parallel to the first cooling fluid channel and is arranged vertically above the thermal insulation material.

[0008] According to further features, the first cooling fluid channel and the second cooling fluid channel have a triangular cross-section.

[0009] According to further features, the first cooling fluid channel and the second cooling fluid channel have the cross-sectional shape of a truncated triangle.

[0010] According to further features, a second thermal insulation material extends rectilinearly toward the rectilinear space, is arranged vertically above the thermal insulation material, and is arranged between the first and second cooling fluid channels.

[0011] According to further features, the second thermal insulation material contains mica.

[0012] According to further features, the second thermal insulation material has a triangular cross-section.

[0013] According to further features, the second thermal insulation material has the cross-sectional shape of a truncated triangle.

[0014] According to further features, the thermal insulation material contains an aerogel.

[0015] According to further features, a second heat transfer material is disposed directly between (a) the first cooling fluid channel and (b) the first sides of the battery cells of a first of the two rectilinear rows; and a third heat transfer material is disposed directly between (a) the second cooling fluid channel and (b) the second sides of the battery cells of a second of the two rectilinear rows.

[0016] According to further features, the battery cells are rectangular prismatic battery cells.

[0017] According to further characteristics, the cooling fluid is air.

[0018] According to further characteristics, the cooling fluid contains water or a refrigerant.

[0019] According to further features, a vehicle contains the battery pack.

[0020] According to one feature, a cooling system includes: the battery pack; and a heating, ventilation, and air conditioning (HVAC) system configured to cool air and supply the cooling air to the first and second cooling fluid channels.

[0021] According to further features, a chiller is configured to supply a coolant to the cooling plate.

[0022] According to one feature, a cooling system includes: the battery pack; and a heating, ventilation, and air conditioning (HVAC) system configured to supply a cooling refrigerant to the first and second cooling fluid channels.

[0023] According to a further feature, a chiller is configured to supply a coolant to the cold plate.

[0024] According to one feature, a cooling system includes: the battery pack; a charging station configured to charge the battery pack and supply the cooling fluid to the first and second cooling fluid channels.

[0025] According to further features, the charging station includes an inlet connector configured to fluidly connect to an input port of the first and second cooling fluid channels and an outlet connector configured to fluidly connect to an output port of the first and second cooling fluid channels.

[0026] According to one feature, a battery pack includes: prismatic battery cells arranged in rectilinear rows; a cooling plate arranged vertically below the battery cells; a heat transfer material arranged between the battery cells and the cooling plate; between each pair of rows, a first thermal insulation material arranged at vertical lower ends of a rectilinear space between the pair of battery cell rows; a first cooling fluid channel configured to receive a cooling fluid, which extends rectilinearly toward the rectilinear space and is arranged vertically above the first thermal insulation material; a second cooling fluid channel configured to receive a cooling fluid, which extends rectilinearly toward the rectilinear space and parallel to the first cooling fluid channel, and is arranged vertically above the first thermal insulation material;and a second thermal insulation material extending linearly toward the linear space and disposed vertically above the first thermal insulation material and between the first and second cooling fluid channels;

[0027] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are provided for purposes of illustration only. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present disclosure will be more fully understood from the detailed description and the accompanying drawings, in which: Fig. 1 a functional block diagram of an exemplary vehicle system; Fig. 2 a perspective view of exemplary battery cells of a battery pack; Fig. 3 a perspective view showing the rows of battery cells of Fig. 2 with insulating material and cooling channels arranged between the rows of battery cells; Fig. 4 a cross-sectional view of the example of Fig. 3; Fig. 5 is a functional block diagram of an exemplary system for heating and cooling the battery pack; Fig. 6 is a functional block diagram of an exemplary system for heating and cooling the battery pack; and Fig. 7 is a functional block diagram and perspective view of an exemplary cooling system including a charging station;

[0029] In the drawings, reference symbols may be used multiple times to identify similar and / or identical elements. DETAILED DESCRIPTION

[0030] A vehicle contains a battery pack that contains two or more battery modules. Each battery module contains multiple battery cells, such as prismatic battery cells. During charging and discharging of the battery pack, the temperature of the battery cells may rise.

[0031] The present application covers systems for heating and cooling battery cells. Cooling channels can be arranged between the upper corners of adjacent battery cells to increase cooling performance, for example, during fast charging. Air or a coolant can flow through the cooling channels to cool the battery cells. This reduces the temperature gradients between the cells and lowers the maximum temperature of the cells, for example, during fast charging. The cooling channels also provide mechanical strength for load bearing without fear of leaks, which can improve package efficiency and reduce costs. The coolant can be provided, for example, by a charging station or a vehicle's heating, ventilation, and air conditioning (HVAC) system.

[0032] In Fig. 1 shows a functional block diagram of an exemplary vehicle system. Although a vehicle system for a hybrid vehicle is shown and described, the present disclosure is also applicable to electric vehicles that do not include an internal combustion engine (including all-electric vehicles), fuel cell vehicles, autonomous vehicles, semi-autonomous vehicles, non-autonomous vehicles, and other types of vehicles. Although the example of a vehicle is provided, the present application is also applicable to non-vehicle implementations.

[0033] An engine 102 may combust an air / fuel mixture to produce drive torque. An engine control module (ECM) 114 controls the engine 102. For example, the ECM 114 may control the actuation of engine actuators such as a throttle valve, one or more spark plugs, one or more fuel injectors, valve actuators, camshaft phasers, an exhaust gas recirculation (EGR) valve, one or more thrust devices, and other suitable engine actuators. For some types of vehicles (e.g., electric vehicles), the engine 102 may be omitted.

[0034] The engine 102 may output torque to a transmission 195. A transmission control module (TCM) 194 controls the operation of the transmission 195. For example, the TCM 194 may control gear selection within the transmission 195 and one or more torque-transmitting devices (e.g., a torque converter, one or more clutches).

[0035] The vehicle system includes one or more electric motors, such as an electric motor 198. An electric motor (also referred to as an electric machine) can act either as a generator or as a motor at a given time. When an electric motor acts as a generator, it converts mechanical energy into electrical energy. The electrical energy can be used, for example, to charge a battery pack 199. When an electric motor acts as a motor, it generates torque that can be used, for example, for vehicle propulsion. Although one electric motor is indicated in the example, the vehicle may include more than one electric motor.

[0036] An engine control module 196 controls the flow of power from the battery pack 199 to the electric motor 198 and from the electric motor 198 to the battery pack 199. The engine control module 196 supplies electrical power from the battery pack 199 to the electric motor 198 to cause the electric motor 198 to output positive torque, such as for vehicle propulsion. As explained later, the battery pack 199 includes one or more battery modules, and each battery module includes a plurality of battery cells.

[0037] For example, the electric motor 198 may output torque to an input shaft of the transmission 195 or to an output shaft of the transmission 195. A clutch 200 may be engaged to couple the electric motor 198 to the transmission 195 and may be disengaged to decouple the electric motor 198 from the transmission 195. One or more gearing devices may be implemented between an output of the clutch 200 and an input of the transmission 195 to provide a predetermined ratio between the rotation of the electric motor 198 and the rotation of the input of the transmission 195.

[0038] The engine control module 196 can also selectively convert mechanical energy of the vehicle into electrical energy. Specifically, the electric motor 198 generates power via the back electromotive force (back EMF) and then outputs it when the electric motor 198 is driven by the transmission 195 and the engine control module 196 is not supplying power from the battery pack 199 to the electric motor 198. The engine control module 196 can charge the battery pack 199 via the power output of the electric motor 198.

[0039] Fig. 2 shows a perspective view of exemplary battery cells of the battery pack 199. The battery pack 199 may include two or more battery modules, each battery module including two or more battery cells. Fig. 2 shows eight battery cells 204.

[0040] Example battery cells are illustrated by 204. Battery cells 204 may be rectangular prismatic battery cells or another suitable type of battery cells. In various implementations, battery pack 199 may include a plurality of different sizes and / or shapes of battery cells.

[0041] The battery cells 204 include opposing left and right side surfaces 208 and 212, opposing front and rear side surfaces 216 and 220, and opposing top and bottom surfaces 224 and 228. Each battery cell 204 includes a positive terminal and a negative terminal, such as 232 and 236. The positive and negative terminals 232 and 236 may both be located on the same side of the battery cell. As shown in Fig. For example, as shown in Figure 2, the positive and negative terminals 232 and 236 are arranged on the top side 224. The positive and negative terminals of the battery cells are electrically connected in series, parallel, or in a combination of series and parallel.

[0042] The battery pack 199 contains at least two rows of battery cells. As shown in Fig. 2, the right side surface 212 of one battery cell, for example, faces the left side surface 208 of another battery cell. This continues to form a row. In Fig. 2 shows two rows of battery cells. In the example of Fig. 2, the rear side surfaces 220 of one row of battery cells 204 face the front side surfaces 216 of another row of battery cells 204.

[0043] Cooling and insulation are contained in a space between adjacent rows of battery cells.

[0044] In Fig. 3 is a perspective view showing the rows of battery cells of Fig. 2 with insulating material and cooling channels arranged between the rows of battery cells. Fig. 4 shows a cross-sectional view from the perspective 304 of Fig. 3.

[0045] As in the Fig. 3 and Fig. As shown in Figure 4, a thermal transfer material (TIM) 404 is embedded between the bottom surfaces of the battery cells 204 and a cold plate 408. The TIM 404 is a thermally conductive material and is configured to conduct heat from the battery cells 204 to the cold plate 408.

[0046] A thermal insulation material 412 is included and fills at least one half of a vertical height 414 of the battery cells 204. The at least one half can extend vertically upward from the bottom. The thermal insulation material 412 can be, for example, an aerogel. The thermal insulation material 412 is intended to thermally insulate adjacent battery cells of different rows.

[0047] A thermal insulation material 416, a TIM 420, and cooling channels 424 are also disposed between the rows of battery cells and vertically above the thermal insulation material 412. The thermal insulation material 416, the TIM 420, and the cooling channels 424 may be disposed horizontally between upper corners of adjacent battery cells of different rows.

[0048] The thermal insulation material 416 may be, for example, mica or another suitable thermally insulating material. The TIM 420 is a thermally conductive material and is configured to transfer heat from the battery cells 204 (near the top corners) to the cooling channels 424. The thermal insulation material 416 is arranged horizontally between the cooling channels 424. Although the example shows two cooling channels, a single cooling channel or more than two cooling channels may be included.

[0049] As shown, a width 432 of the thermal insulation material 416 may decrease vertically upward in a horizontal direction perpendicular to the side surfaces of the battery cells 204. A cross-section of the thermal insulation material 416 may be triangular or have the shape of a truncated triangle.

[0050] A width 436 inside the cooling channels 424 may decrease vertically downward in a horizontal direction perpendicular to the side surfaces of the battery cells 204. A cross-section of the cooling channels 424 may be triangular or have the shape of a truncated triangle. This shape may provide increased cooling for the upper corners of the battery cells 204.

[0051] A cooling fluid flows through the cooling channels 424 (which may also be referred to as coolant channels) and absorbs heat from the battery cells 204. The cooling channels 424 may be made of a thermally conductive material such as aluminum, copper, or another suitable thermally conductive material. The two cooling channels 424 shown may help dissipate heat more evenly from both rows of battery cells 204.

[0052] Fig. 5 shows a functional block diagram of an example system for heating and cooling the battery pack 199; solid lines indicate air. Dotted lines indicate a liquid coolant (e.g., water or antifreeze). Lines alternating between dashes and dots indicate a refrigerant of the heating, ventilation, and air conditioning (HVAC) system. As shown in Fig. For example, as shown in Figure 5, air cooled by an evaporator 504 of an HVAC system for a passenger compartment 508 of the vehicle flows through the cooling channels 424.

[0053] In the HVAC system, a compressor 512 compresses the refrigerant and delivers it to a condenser 516. The refrigerant flows from the condenser to an expansion valve 520 before flowing to the evaporator 504. The evaporator 504 cools air flowing through and past the evaporator 504. A blower or fan 524 may increase the airflow through and / or past the evaporator 504. The air cooled by the evaporator may flow into the passenger compartment 508 to provide cooling within the passenger compartment 508.

[0054] The refrigerant discharged from the expansion valve 520 may also flow to a chiller 528 before being returned to the compressor 512. The chiller 528 may transfer heat from the liquid coolant to the refrigerant and cool the liquid coolant.

[0055] In the liquid coolant loop, chilled liquid coolant output from chiller 528 flows to cold plate 408 to cool battery cells 204 via the undersides of battery cells 204. Warmer liquid coolant output from cold plate 408 may flow to radiator 532, which may transfer heat from the liquid coolant to the air flowing around radiator 532.

[0056] The cooled air discharged from the evaporator 504 may flow to a valve 536. When the valve 536 is open, the cooled air may flow to and through the cooling channels 424 to cool the rows of battery cells 204. A valve control module 540 may control the opening and closing of the valve 536. The valve control module 540 may open the valve 536, for example, when the battery pack 199 is being charged or discharged, when a temperature of a battery cell is higher than a predetermined temperature, and / or when one or more other predetermined conditions are met.

[0057] Fig. Figure 6 shows a functional block diagram of an example system for heating and cooling the battery pack 199; solid lines indicate air. Dotted lines indicate a liquid coolant (e.g., water or antifreeze). Lines alternating between dashes and dots indicate a refrigerant of the heating, ventilation, and air conditioning (HVAC) system. As shown in Fig. For example, as shown in Figure 6, the cool refrigerant of the HVAC system flows through the cooling channels 424 to cool the rows of battery cells 204.

[0058] For example, the refrigerant discharged from the expansion valve 520 flows to the cooling channels 424. The refrigerant discharged from the cooling channels 424 may be returned to the compressor 512.

[0059] A valve 604 may be implemented to regulate the flow of refrigerant through the chiller 528. The valve control module 540 may open the valve 540, for example, when the battery pack 199 is being charged or discharged, when a temperature of a battery cell is higher than a predetermined temperature, and / or when one or more other predetermined conditions are met.

[0060] Fig. Figure 7 shows a functional block diagram and a perspective view of an exemplary cooling system including a charging station 704. The charging station 704 can charge the battery pack 199.

[0061] For example, cooling fluid may be supplied through the charging station 704 and flow between the rows of battery cells 204 through the cooling channels 424. The vehicle may include a cooling fluid input port 708 and a cooling fluid output port 712. The cooling fluid input port 708 may be connected to an input manifold 716 to which the inlets of the cooling channels 424 between each row of battery cells 204 are fluidly connected and receive cooled cooling fluid therefrom. The cooling fluid output port 712 may be connected to an output manifold 722 to which the outlets of the cooling channels 424 between each row of battery cells 204 are fluidly connected and receive heated cooling fluid therefrom.

[0062] The charging station 704 may include an inlet connector 724 configured to fluidly connect directly to the cooling fluid input port 708. In various implementations, a cooling line (e.g., a hose) may be fluidly connected between the cooling fluid input port 708 and the inlet connector 724 and fluidly connect the inlet connector 724 and the cooling fluid input port 708.

[0063] The charging station 704 may include an outlet connector 728 configured to fluidly connect directly to the cooling fluid output port 712. In various implementations, a cooling line (e.g., a hose) may be fluidly connected between the cooling fluid output port 712 and the outlet connector 728 to fluidly connect the outlet connector 728 and the cooling fluid output port 712.

[0064] A pump 732 pumps relatively cooler cooling fluid (e.g., air, water, antifreeze, refrigerant) to the cooling channels 424 via the inlet connector 724 and the cooling fluid input port 708. The cooling fluid cools the battery cells 204 of the rows and becomes warmer. The relatively warmer cooling fluid is returned to a coolant tank 734 via the outlet connector 728 and the cooling fluid output port 712.

[0065] A control module 736 may control whether the pump 732 is on or off. For example, when the charging station 704 is charging the battery pack 199, the control module 736 may turn on the pump 732 and cool the battery cells 204. In various implementations, the control module 736 may control a speed of the pump 732. For example, the control module 736 may increase the speed of the pump 732 when a temperature of the battery pack 199 increases, and vice versa.

[0066] Additionally, a compressor 750 may be included. The control module 736 may operate the compressor 750 to discharge the cooling fluid from the battery pack 199 when charging of the battery pack 199 is complete. The compressor 750 may supply, for example, compressed air to the input port 708.

[0067] The cooling system provided here provides additional cooling to allow for faster charging. Cooling the corners reduces the temperature gradient of the cells during charging and reduces the maximum temperature experienced during charging. The cooling channels also increase mechanical strength for load-bearing, which can improve packaging efficiency and / or reduce battery pack costs. The inclusion of two cooling channels can help provide protection against thermal runaway (and prevent thermal runaway). The thermal insulation material between the cooling channels can also provide protection against thermal runaway. The shape of the cooling channels (triangular cross-section or truncated triangle shape), discussed previously, can help accommodate uneven expansion of the battery cells.

Claims

[1] Battery pack (199), which includes: prismatic battery cells (204) arranged in two straight rows; a cooling plate (408) arranged vertically below the battery cells (204); a heat transfer material (404) disposed between the battery cells (204) and the cooling plate (408); a thermal insulation material (412) arranged at vertical lower ends of a linear space between the two linear rows of battery cells (204); a first cooling fluid channel (424) configured to receive a cooling fluid and extending rectilinearly toward the rectilinear space and disposed vertically above the thermal insulation material (412); and a second cooling fluid channel (424) configured to receive the cooling fluid and extending rectilinearly toward the rectilinear space and disposed parallel to the first cooling fluid channel (424) and vertically above the thermal insulation material (412). [2] The battery pack (199) of claim 1, wherein the first and second cooling fluid channels (424) have a triangular cross-section. [3] The battery pack (199) of claim 1, wherein the first cooling fluid channel (424) and the second cooling fluid channel (424) have a cross-sectional shape of a truncated triangle. [4] The battery pack (199) of claim 1, further including a second thermal insulation material (416) extending linearly toward the linear space and disposed vertically above the thermal insulation material (412) and between the first and second cooling fluid channels (424). [5] The battery pack (199) of claim 4, wherein the second thermal insulation material (416) includes mica. [6] The battery pack (199) of claim 4, wherein the second thermal insulation material (416) has a triangular cross-section. [7] The battery pack (199) of claim 4, wherein the second thermal insulation material (416) has a cross-sectional shape of a truncated triangle. [8] The battery pack (199) of claim 1, wherein the thermal insulation material (412) comprises an aerogel. [9] The battery pack (199) of claim 1, further comprising: a second heat transfer material (420) disposed directly between (a) the first cooling fluid channel (424) and (b) the first sides of the battery cells (204) of a first of the two rectilinear rows; and a third heat transfer material (420) disposed directly between (a) the second cooling fluid channel (424) and (b) the second sides of the battery cells (204) of a second of the two rectilinear rows. [10] The battery pack (199) of claim 1, wherein the battery cells (204) are rectangular prismatic battery cells (204).

Images