Cooling system and battery pack

Abstract

The utility model belongs to the technical field of battery heat dissipation, and particularly discloses a cooling system which comprises a phase change cooling assembly and a liquid cooling assembly. The phase change cooling assembly is arranged on the busbar and extends in the first direction away from the batteries, the phase change cooling assembly is filled with a phase change medium, and phase change occurs after heat absorption of the phase change medium, so that the tops of the batteries are indirectly cooled. The liquid cooling assemblies are arranged at the bottoms of the batteries, and the bottoms of the batteries can be cooled through the liquid cooling assemblies, so that the temperature difference between the tops and the bottoms of the batteries is reduced, the temperature uniformity of the batteries is good, and the service life of the batteries is prolonged. The utility model further provides a battery pack which comprises the cooling system, the phase change cooling assembly of the cooling system can cool the top of the battery, the liquid cooling assembly can cool the bottom of the battery at the same time, the temperature difference between the top and the bottom of the battery is small, the temperature uniformity is good, the service life of the battery is long, and the safety performance is good.

Description

Technical Field

[0001] The utility model relates to the technical field of battery heat dissipation, and in particular to a cooling system and a battery pack. Background Art

[0002] In recent years, lithium-ion batteries have become the fastest-growing new energy storage technology and the mainstream route for electrochemical energy storage due to their superior comprehensive performance, high energy density, high charge and discharge efficiency, and fast response speed. High safety, low cost, and long life are the core requirements of lithium battery energy storage systems, which are closely related to the temperature of lithium batteries. Therefore, how to effectively control the temperature uniformity of lithium batteries during use is a key issue that needs to be solved urgently.

[0003] As the smallest integrated unit of lithium battery energy storage products, the battery pack is currently subject to air cooling and liquid cooling. Liquid cooling is mainly indirect liquid cooling, that is, a liquid cooling plate is set at the bottom of the battery pack. Figure 1 , the heat of the battery 10' is indirectly taken away by the flow of the fluid medium in the liquid cooling plate 11'. However, in this technical solution, the heat exchange efficiency through indirect liquid cooling is not high, and the heat dissipation is not timely. And because the main heat-generating part of the battery 10' is the pole ear 12', and the liquid cooling plate 11' is arranged at the bottom of the battery 10', the heat of the battery 10' can only be indirectly dissipated through the bottom liquid cooling plate 11', and the pole ear 12' cannot be cooled, resulting in a large temperature difference between the top and bottom of the battery 10'. Moreover, with the market demand for high-rate batteries for energy storage and more charge and discharge times, it is difficult to achieve temperature difference management of the battery 10'. The temperature at the top of the battery 10' may be as high as 55°C or above, and it is difficult to maintain a suitable operating temperature, which seriously affects the service life of the battery 10' and the safety of the energy storage system. Utility Model Content

[0004] The purpose of the utility model is to provide a cooling system and a battery pack, wherein a heat pipe is provided on the top of the battery for heat dissipation, and a liquid cooling plate is provided on the bottom of the battery for heat dissipation, so that the top and bottom of the battery can both achieve rapid heat dissipation, the battery has good temperature uniformity, extended service life, and good safety performance.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] On the one hand, the utility model provides a cooling system for dissipating heat for a plurality of batteries, wherein the top of each battery comprises a tab, and the tabs of two adjacent batteries are connected by a bus bar, and the cooling system comprises:

[0007] A phase change cooling component is arranged on the bus and extends in a first direction away from the battery, the phase change cooling component is filled with a phase change medium, and the phase change medium undergoes a phase change inside the phase change cooling component after absorbing heat from the bus;

[0008] The liquid cooling component is arranged at the bottom of the battery and connected to the bottom of the battery. A cooling medium flows through the liquid cooling component, and the cooling medium is used for exchanging heat with the bottom of the battery.

[0009] Optionally, the phase change cooling assembly includes a plurality of heat pipes, the plurality of heat pipes correspond to the busbar one by one, and the bottom end of each heat pipe is connected to a side of the busbar away from the battery;

[0010] In the first direction, the liquid cooling assembly, a plurality of the batteries, a plurality of the bus bars, and a plurality of the heat pipes are sequentially arranged.

[0011] Optionally, the heat pipe includes a tube shell and a liquid wick, the interior of the tube shell forms a closed accommodating cavity, the liquid wick is arranged on the inner wall of the tube shell, the phase change medium is liquid at room temperature, and the liquid phase change medium is adsorbed on the liquid wick.

[0012] Optionally, a heat absorption section, a heat insulation section and a condensation section which are connected in sequence are formed inside the tube shell, and the heat absorption section is located at one end of the tube shell close to the battery.

[0013] Optionally, the tube shell includes a peripheral side plate, and a top plate and a bottom plate arranged at both ends of the peripheral side plate, the liquid absorbent core is arranged on the peripheral side plate, and the top plate and the bottom plate are circular.

[0014] Optionally, the bottom plate of the heat pipe is insulated and welded to a side of the busbar facing away from the battery.

[0015] Optionally, the liquid cooling assembly includes a liquid cooling plate, the cooling medium flows through the liquid cooling plate, and the plurality of batteries are fixed on the liquid cooling plate.

[0016] Optionally, the liquid cooling component also includes a cooling unit, a water inlet pipe and a water return pipe. The liquid cooling plate is provided with a water inlet and a water outlet. The two ends of the water inlet pipe are respectively connected to the water inlet and the cooling unit, and the two ends of the return pipe are respectively connected to the water outlet and the cooling unit.

[0017] Optionally, the plurality of batteries are stacked in sequence along the length direction of the liquid cooling plate, and an end plate is respectively provided at both ends of the plurality of batteries, and the end plate is used to fix the plurality of batteries.

[0018] On the other hand, the utility model provides a battery pack, comprising a plurality of batteries and a cooling system in any of the above schemes, wherein the cooling system is used to cool the top and bottom of the battery.

[0019] The beneficial effects of the utility model are:

[0020] The utility model provides a cooling system, including a phase change cooling component and a liquid cooling component. The phase change cooling component is arranged on a bus and extends in a first direction away from the battery. The phase change cooling component is filled with a phase change medium, and the phase change medium absorbs heat and undergoes a phase change, thereby indirectly cooling the tops of multiple batteries. The liquid cooling component is arranged at the bottom of multiple batteries, and the bottom of the battery can be cooled by the liquid cooling component, thereby reducing the temperature difference between the top and bottom of the battery, and the battery has good temperature uniformity, which is conducive to extending the service life of the battery.

[0021] The utility model also provides a battery pack, including multiple batteries and the above-mentioned cooling system. The top of the battery can be cooled by the heat pipe of the cooling system, and the bottom of the battery can be cooled at the same time by the liquid cooling component, thereby avoiding thermal runaway caused by excessive battery temperature and having better safety. At the same time, the temperature difference between the top and the bottom of the battery is small, the temperature uniformity is good, and the battery has a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the battery pack in the traditional technical solution;

[0023] Figure 2 It is a schematic diagram of the structure of the battery pack provided in the embodiment of the utility model;

[0024] Figure 3 yes Figure 2 A partial enlarged view of the middle A;

[0025] Figure 4 It is a schematic diagram of the structure of the heat pipe provided in the embodiment of the utility model;

[0026] Figure 5 yes Figure 4 Cross-sectional view of the BB section.

[0027] In the figure:

[0028] 10', battery; 11', liquid cooling plate; 12', tab;

[0029] 100, battery; 110, tab; 120, bus; 200, heat pipe; 201, liquid phase change medium; 202, gaseous phase change medium; 210, tube shell; 211, peripheral side plate; 212, top plate; 213, bottom plate; 220, liquid wick; 300, liquid cooling plate; 310, water inlet; 400, end plate. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0034] This embodiment provides a cooling system, which can be used to dissipate heat from the tops and bottoms of multiple batteries 100 at the same time, thereby reducing the temperature difference between the top and bottom of the battery 100, improving the uniformity of the overall temperature of the battery 100, and helping to extend the service life of the battery 100.

[0035] like Figure 2 and Figure 3As shown, the top of each battery 100 includes a tab 110, and the tabs 110 of two adjacent batteries 100 are connected by a bus 120, and the adjacent batteries 100 are connected in series or in parallel through the bus 120. The cooling system in this embodiment includes a phase change cooling component and a liquid cooling component. The phase change cooling component is arranged on the bus 120 and extends in a first direction away from the battery 100, such as Figure 2 As shown in , the first direction is: from the bottom of the battery 100 to the top of the battery 100. The heat of the busbar 120 and the tab 110 can be taken away by the phase change cooling assembly, and the heat on the top of the battery 100 is mostly concentrated at the busbar 120 and the tab 110, so that the phase change cooling assembly can cool the tops of multiple batteries 100. The liquid cooling assembly is arranged at the bottom of multiple batteries 100, and the bottom of the battery 100 can be cooled by the liquid cooling assembly, thereby reducing the temperature difference between the top and bottom of the battery 100, and the battery 100 has good temperature uniformity.

[0036] As an optional solution, in this embodiment, the phase change cooling assembly is connected to the side of the bus 120 away from the battery 100, and the phase change cooling assembly is filled with a phase change medium. The phase change medium absorbs the heat at the top of the battery 100 (including the heat generated by the pole ear 110 and the heat transferred from the pole ear 110 to the bus 120) and then becomes gaseous. The gaseous phase change medium 202 diffuses from the end close to the battery 100 to the end away from the battery 100, and condenses at the end away from the battery 100, and then flows back to the end close to the battery 100 again, and so on. The cycle is repeated to take away the heat from the top of the battery 100, and the top of the battery 100 is cooled, and the heat dissipation effect is good. Further, the liquid cooling assembly is connected to the bottom of multiple batteries 100, and a cooling medium circulates in the liquid cooling assembly. The cooling medium exchanges heat with the bottom of the battery 100, thereby taking away the heat from the bottom of the battery 100 and cooling the bottom of the battery 100.

[0037] Furthermore, the phase change cooling assembly includes a plurality of heat pipes 200, and the plurality of heat pipes 200 correspond to the bus 120 one by one. The bottom end of each heat pipe 200 is connected to the side of the bus 120 away from the battery 100, and the phase change medium undergoes a phase change inside the heat pipe 200 after absorbing the heat from the bus 120 and the tab 110. By utilizing the heat dissipation principle of the heat pipe 200, the heat at the top of the battery 100 is indirectly taken away, thereby reducing the temperature difference between the top and bottom of the battery 100, maintaining the temperature uniformity of the battery 100, extending the service life of the battery 100, and improving the safety performance. And as an optional solution, in this embodiment, the liquid cooling assembly, the plurality of batteries 100, the plurality of buses 120 and the plurality of heat pipes 200 are arranged along Figure 2The first direction is arranged in sequence, wherein multiple batteries 100 are arranged side by side along the length direction of the liquid cooling assembly, the length direction of the liquid cooling assembly is perpendicular to the first direction, and multiple bus bars 120 are used to connect two adjacent batteries 100 in series or in parallel, and each bus bar 120 is connected to a heat pipe 200.

[0038] See also Figure 4 and Figure 5 In this embodiment, the heat pipe 200 includes a tube shell 210 and a liquid wick 220. The interior of the tube shell 210 forms a closed accommodating cavity. The liquid wick 220 is arranged on the inner wall of the tube shell 210. The phase change medium is liquid at room temperature, and the liquid phase change medium 201 is adsorbed on the liquid wick 220. Exemplarily, the phase change medium that is liquid at room temperature can be selected from one of hexane, acetone, ethanol, methanol, toluene or water.

[0039] Furthermore, a heat absorbing section, a heat insulating section and a condensing section connected in sequence are formed inside the tube shell 210, and the heat absorbing section is located at one end of the tube shell 210 close to the battery 100. Specifically, after the heat absorbing section absorbs heat, it can cause the liquid phase change medium 201 to evaporate into a gaseous state, and the gaseous phase change medium 202 diffuses to the condensing section through the heat insulating section, and dissipates heat in the condensing section. At this time, the gaseous phase change medium 202 condenses into a liquid phase change medium 201, and flows back to the heat absorbing section through the liquid absorption core 220 on the inner wall of the tube shell 210 to circulate again, thereby continuously dissipating the heat at the top of the battery 100 in a reciprocating cycle, achieving cooling of the top of the battery 100, and avoiding thermal runaway caused by excessive local temperature of the battery 100.

[0040] Optionally, the tube shell 210 is cylindrical as a whole, including a peripheral side plate 211, and a top plate 212 and a bottom plate 213 arranged at both ends of the peripheral side plate 211, the top plate 212 and the bottom plate 213 are circular, and the peripheral side plate 211 is connected with the top plate 212 and the bottom plate 213 to form a closed accommodating cavity. The wick 220 is arranged on the peripheral side plate 211, the side close to the bottom plate 213 is the above-mentioned heat absorption section, the side close to the top plate 212 is the above-mentioned condensation section, and the part between the heat absorption section and the condensation section is the insulation section. By setting the tube shell 210 to a cylindrical shape, the contact area between the condensation section of the heat pipe 200 and the outside world is larger, which is conducive to the heat dissipation of the heat pipe 200 and accelerates the heat dissipation.

[0041] Exemplarily, the bottom plate 213 of the heat pipe 200 is insulated and welded to the side of the bus bar 120 facing away from the battery 100, thereby fixing the heat pipe 200 to the bus bar 120 and ensuring insulation between the heat pipe 200 and the bus bar 120. The specific insulation welding technology is a mature technical means in the field and will not be described in detail here.

[0042] Continue to see Figure 2The liquid cooling assembly in this embodiment includes a liquid cooling plate 300, in which a cooling medium flows, and a plurality of batteries 100 are fixed on the liquid cooling plate 300. The temperature of the cooling medium is lower than the temperature of the bottom of the battery 100. After the cooling medium exchanges heat with the bottom of the battery 100, the heat at the bottom of the plurality of batteries 100 is continuously dissipated through the cooling medium in the liquid cooling plate 300, thereby achieving the effect of cooling the bottom of the battery 100.

[0043] Further, the liquid cooling assembly also includes a cooling unit, a water inlet pipe and a water return pipe (not shown in the figure), and a water inlet 310 and a water outlet are provided on the liquid cooling plate 300. The two ends of the water inlet pipe are respectively connected to the water inlet 310 and the cooling unit, and the two ends of the water return pipe are respectively connected to the water outlet and the cooling unit. The cooling medium circulates in the cooling unit, the water inlet pipe, the liquid cooling plate 300 and the water return pipe. The cooling medium absorbs the heat at the bottom of the battery 100 at the liquid cooling plate 300 and heats up, and then flows into the cooling unit through the water return pipe. The cooling unit can cool down the heated cooling medium so that the cooling medium entering the liquid cooling plate 300 through the water inlet pipe again is kept at a lower temperature, and the cooling unit can temporarily store part of the cooling medium. It should be noted that the cooling unit is equipped with a circulating water pump, which can provide a power source for the flow of the cooling medium. The circulating water pump drives the cooling medium to circulate between the water inlet pipe, the liquid cooling plate 300 and the water return pipe.

[0044] Continue to see Figure 2 , multiple batteries 100 are stacked in sequence along the length direction of the liquid cooling plate 300, and an end plate 400 is respectively provided at both ends of the multiple batteries 100, and the end plate 400 is used to fix the multiple batteries 100. Optionally, the two end plates 400 can be fixed to the liquid cooling plate 300 by bonding or bolting, so that the two end plates 400 clamp the multiple batteries 100 and fix their positions, and the multiple batteries 100 are grouped.

[0045] The present embodiment also provides a battery pack, comprising a plurality of batteries 100, and the above-mentioned cooling system. The heat pipe 200 of the cooling system can cool the top of the battery 100, and the bottom of the battery 100 can be cooled simultaneously through the liquid cooling plate 300, thereby avoiding thermal runaway caused by excessive temperature of the battery 100, and having better safety. At the same time, the temperature difference between the top and the bottom of the battery 100 is small, the temperature uniformity is good, and the service life of the battery 100 is long.

[0046] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A cooling system for dissipating heat from a plurality of batteries (100), wherein the top of each battery (100) comprises a tab (110), and the tabs (110) of two adjacent batteries (100) are connected via a bus bar (120), characterized in that: The cooling system comprises: a phase change cooling component, arranged on the bus (120) and extending in a first direction away from the battery (100), the phase change cooling component being filled with a phase change medium, the phase change medium undergoing a phase change inside the phase change cooling component after absorbing heat from the bus (120); A liquid cooling component is arranged at the bottom of the battery (100) and connected to the bottom of the battery (100); a cooling medium flows through the liquid cooling component, and the cooling medium is used to exchange heat with the bottom of the battery (100).

2. The cooling system according to claim 1, characterized in that: The phase change cooling component comprises a plurality of heat pipes (200), the plurality of heat pipes (200) correspond to the busbar (120) one by one, and the bottom end of each heat pipe (200) is connected to a side of the busbar (120) facing away from the battery (100); In the first direction, the liquid cooling assembly, a plurality of the batteries (100), a plurality of the bus bars (120) and a plurality of the heat pipes (200) are arranged in sequence.

3. The cooling system according to claim 2, characterized in that: The heat pipe (200) comprises a tube shell (210) and a liquid wick (220); a closed accommodating cavity is formed inside the tube shell (210); the liquid wick (220) is arranged on the inner wall of the tube shell (210); the phase change medium is in liquid state at room temperature; and the liquid phase change medium (201) is adsorbed on the liquid wick (220).

4. The cooling system according to claim 3, characterized in that: A heat absorption section, a heat insulation section and a condensation section which are connected in sequence are formed inside the tube shell (210), and the heat absorption section is located at one end of the tube shell (210) close to the battery (100).

5. The cooling system according to claim 3, characterized in that: The tube shell (210) comprises a peripheral side plate (211), and a top plate (212) and a bottom plate (213) arranged at both ends of the peripheral side plate (211); the liquid absorbent core (220) is arranged on the peripheral side plate (211); and the top plate (212) and the bottom plate (213) are circular.

6. The cooling system according to claim 4, characterized in that: The bottom plate (213) of the heat pipe (200) and the side of the busbar (120) facing away from the battery (100) are insulated and welded.

7. The cooling system according to claim 1, characterized in that: The liquid cooling assembly comprises a liquid cooling plate (300), the cooling medium flows in the liquid cooling plate (300), and a plurality of the batteries (100) are fixed on the liquid cooling plate (300).

8. The cooling system according to claim 7, characterized in that: The liquid cooling assembly also includes a cooling unit, a water inlet pipe and a water return pipe. The liquid cooling plate (300) is provided with a water inlet (310) and a water outlet. The two ends of the water inlet pipe are respectively connected to the water inlet (310) and the cooling unit, and the two ends of the water return pipe are respectively connected to the water outlet and the cooling unit.

9. The cooling system according to claim 7, characterized in that: The multiple batteries (100) are stacked in sequence along the length direction of the liquid cooling plate (300), and an end plate (400) is respectively provided at both ends of the multiple batteries (100), and the end plate (400) is used to fix the multiple batteries (100).

10. A battery pack, characterized in that: The invention comprises a plurality of batteries (100) and a cooling system according to any one of claims 1 to 9, wherein the cooling system is used to cool the top and bottom of the batteries (100).

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