Battery module using pouch battery

Abstract

A battery pack module made of a plurality of side-by-side pouch battery modules, where each pouch battery module is formed with a pair of batteries on either side of an insulating pad, where the batteries are in turn positioned between first and second metal brackets such that each battery contacts the insulating pad on one side and contacts the metal brackets on the other side. Also included are a pair of pressure plates at the ends of the stack of side-by-side pouch cells and a compression strap wrapped around the plurality of side-by-side pouch cells and the pressure plates. The bus bar electrically connects the plurality of side-by-side pouch cells together.

Description

[0001] This application is a divisional application of the invention patent application with application number No. 202080066722.0 filed on July 31, 2020, and the invention name is “Battery pack module using pouch batteries”. Technical Field

[0002] The present application relates to systems for holding pouch battery cells together as a unit for an electric vehicle and to systems for removing heat from such pouch battery cells to improve battery performance. Background Art

[0003] Battery power supplies used in electric vehicles, such as electric motor vehicles, typically include a large number of individual battery pouch cell modules that are in close contact with each other. Pouch cells provide the best use of space and packaging efficiency. Unfortunately, the main problem with stacking these electric vehicle battery pouch cells closely together is the heat generated by the individual battery cells. Overheating of the battery pack can cause problems. First, it causes the overall power efficiency to be compromised. Second, this overheating can also cause safety issues.

[0004] Unfortunately, it has proven difficult to effectively remove heat from electric vehicle battery cells. One existing solution to this problem is to use cooling gel in the battery module. In this approach, a thermal glue or gel is applied to the inside of the bottom housing to remove heat from the bottom housing. Since the glue or gel is only located at the bottom of the housing, this typically results in a large temperature difference across the cell perpendicular to the cooling surface. Another approach is to hold the individual battery cells together in a plastic frame and then cool the plastic frame together with cooling foam. This is not cost effective and has a high risk of liquid leaks inside the module. Instead, it is desirable to provide an enhanced electric vehicle battery cooling system for battery cells that are stacked closely together that provides better temperature control at a lower cost. Additionally, it is desirable to provide a battery cell stacking system that physically protects the individual battery cells. Summary of the invention

[0005] According to the present application, a system for holding a plurality of electric vehicle battery pack pouch cells together is disclosed herein. As will be shown, the present system both protects the individual batteries and effectively removes heat from them. In a preferred aspect, the present system includes: (a) a plurality of pouch battery modules positioned side by side, wherein each pouch battery module includes: (i) a first bracket, (ii) a second bracket, (iii) a pair of battery cells positioned between the first and second brackets, and (iv) an insulating pad positioned between the pair of battery cells; (b) a pair of pressure plates, wherein a pressure plate is provided at each end of the battery module; (c) at least two compression bands, which are wrapped around a plurality of side-by-side pouch batteries and end pressure plates; (d) a busbar, which electrically connects a plurality of side-by-side pouch battery modules together. Preferably, a top cover spanning the top of the plurality of side-by-side pouch battery modules is also included; and a bottom cover spanning the bottom of the plurality of side-by-side pouch battery modules.

[0006] In a preferred embodiment, each parallel-connected battery in the pouch battery module has top and bottom tabs fastened together. Busbars are then welded to the top and bottom tabs of the battery module to provide electrical connectivity between all the batteries.

[0007] In a preferred embodiment, the first bracket of each single pouch battery module has a longitudinally extending side edge and the second bracket is positioned between (ie, contained within) the longitudinally extending side edges of the first bracket. Thus, the pouch battery module is provided with two battery cells, which are held between the first and second brackets and the insulating pad is positioned between the two batteries. As a result, one face of each single battery cell is in contact with the metal bracket and the other face is in contact with the insulating pad. When the pouch battery modules are stacked side by side, this pattern is repeated across the length of the entire assembly. Since each battery cell in the assembly is in direct physical contact with the metal bracket on one side, this novel design provides enhanced cooling benefits. This allows excess heat to be conducted away from the battery cells quickly and efficiently. In addition, positioning the insulating pad between the batteries directs excess heat from each single battery cell away from the insulating pad and into one of the adjacent metal brackets. To facilitate heat conduction, the first bracket and the second bracket may preferably be made of aluminum, and to prevent heat transfer, the insulating pad may be made of an insulating material having a low thermal conductivity.

[0008] Also preferably, the top and bottom covers of the device may have edges that wrap around the top and bottom ends of the plurality of pouch battery modules, and the first bracket may have a recess therein for receiving the compression strap in the recess when the compression strap is wrapped around the entire assembly.

[0009] A first advantage of the present system is that it provides enhanced cooling by conducting heat away from each battery cell because each battery cell is in contact with one or the other of the first and second metal brackets of the module.

[0010] A second advantage of the present system is that there is no possibility of coolant leaks in the module (compared to prior systems which circulate cooling fluid through cold plates between the individual cells).

[0011] A third advantage of the present system is that its design is completely modular. Thus, different numbers of pouch cell modules can be stacked side by side, with the present system operating in the same manner in each of its various configurations (i.e., with more or fewer pouch cells). Thus, more pouch cell modules can be added, or pouch cell modules can be removed from the system, all depending on the user's requirements.

[0012] A fourth advantage of the present system is that it can be used with different pouch battery wirings, for example, the pouch batteries can be connected in 3S8P (i.e., 3 battery packs in series and 8 battery packs in parallel) or 3P12S (i.e., 3 battery packs in series and 12 battery packs in parallel), 6P8S (i.e., 6 battery packs in parallel and 8 battery packs in series) and / or any other desired configuration.

[0013] A fifth advantage of the present system is that it provides structural protection for the battery cells. Specifically, its metal bracket is more rigid than the comparable plastic frame used in existing foam designs. In addition, the bracket of the present invention does not cause any internal leakage of coolant. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a partially exploded perspective view of the system.

[0015] Figure 2 is corresponding to Figure 1 Assembly perspective view of the .

[0016] Figure 3 is a perspective view of one of the individual battery cells.

[0017] Figure 4 yes Figure 1 and 2 A perspective view of a pair of systems positioned side by side and separated by a cooling plate.

[0018] Figure 5 yes Figure 4 Multiple systems positioned together end-to-end.

[0019] Figure 6 is a perspective view of a plurality of the present invention systems positioned together in a channel arrangement along a center console. DETAILED DESCRIPTION

[0020] First reference Figure 1 and 2 , a battery pack module 10 is provided. The battery pack module 10 includes a plurality of pouch battery modules 20 positioned side by side. Each pouch battery module 20 includes a first bracket 22 and a second bracket 24. A pair of pouch batteries 32 and 34 are positioned between the first and second brackets 22 and 24. An insulating pad 35 is positioned between the batteries 32 and 34, as shown. In operation, the brackets 22 and 24 provide strong structural support on the sides of the batteries 32 and 34. In addition, the brackets 22 and 24 are preferably made of a highly thermally conductive material (which material may optionally be aluminum) to effectively conduct excess heat away from the batteries 32 and 34. It is also preferred that the batteries 32 and 34 have a large side surface area (see Figure 3 ), which directly contacts the brackets 22 and 24 to ensure efficient heat transfer. It can also be seen that each individual battery cell (i.e., each battery 32 or 34) in each pouch battery module 20 in the entire battery module 10 is in direct physical contact with the metal bracket (22 or 24), so that heat can be quickly and efficiently conducted away from the battery. Preferably, the first bracket 22 and the second bracket 24 are made of aluminum or other suitable high thermal conductivity materials, and the insulating pad is preferably made of low thermal conductivity material or any suitable insulating material.

[0021] A pressure plate 38 is provided on each of the two lateral ends of the battery module 10. An optional insulating pad 39 may be provided adjacent to each pressure plate 38 to prevent overheating at the lateral ends of the battery module 10. An optional slave board or module control unit 50 may be attached to the pressure plate 38 via a wiring harness 52. The module control unit 50 may optionally be used to measure cell voltage and temperature and communicate this information to the battery management unit.

[0022] A bus bar 60 is provided to electrically connect each battery in the plurality of side-by-side pouch battery modules 20. Figure 1 As best shown, each of the cells 32 and 34 can have top and bottom tabs 31 extending therefrom, and the top and bottom tabs are fastened together. Specifically, this placement also keeps each of the cells 32 and 34 in direct physical contact with the insulating pad 35. Since the busbar 60 is also electrically and preferably physically connected to the tabs 31, this also helps to hold the entire pouch battery module 20 together. In a preferred embodiment, the busbar 60 is ultrasonically welded to the top tabs 31 of the cells 32 and 34.

[0023] like Figure 1As can be seen in the figure, the first bracket 22 can have longitudinally extending side edges 23 that are received around the second bracket 24 so that the batteries 32 and 34 together with the insulating pads 35 are located between the longitudinally extending side edges 23 of the first bracket 22. This has the advantage of providing structural stability to each pouch battery module 20.

[0024] In a preferred aspect, at least one compression band 70 is wrapped around a plurality of side-by-side pouch battery modules 20 and a pair of pressure plates 38. In a preferred aspect, the longitudinally extending side edges 23 of the first bracket 22 all have notches 27 therein so that the compression band 70 can be received in the notches, thereby keeping the entire assembly together. To further provide structural stability, an optional top cover 80 across the top of the plurality of side-by-side pouch battery modules 20 and an optional bottom cover 84 across the bottom of the plurality of side-by-side pouch battery modules 20 are also provided. The top cover 80 preferably has a downwardly extending edge 82 that wraps around the top end of each of the plurality of pouch battery modules 20, and the bottom cover 84 preferably has an upwardly extending edge 86 that wraps around the bottom end of each of the plurality of pouch battery modules 20. As seen, the at least one compression band 70 preferably includes an upper compression band and a lower compression band, both of which are wrapped around the plurality of side-by-side pouch battery modules 20 (and also around the two end pressure plates 38). However, it should be understood that any number of compression bands 70 may be provided as desired. Furthermore, such compression bands may be thin and cover only a small portion of the device, or may be wide and cover a large or very large portion of the surface of the longitudinally extending side edges 23 .

[0025] It should be understood that the present system is not limited to any particular wiring arrangement for electrically connecting the individual battery packs used in each of the batteries 32 and 34. For example, the present system can be used with different pouch cell wiring designs, such as pouch cells wired in 3S4P (i.e., 3 battery packs in series, 4 battery packs in parallel) or 3P12S (i.e., 3 battery packs in series, 12 battery packs in parallel), 6P8S (i.e., 6 battery packs in parallel, 8 battery packs in series), and or any other desired configuration.

[0026] In an alternative embodiment, a voltage and temperature sensing board 90 may be positioned in electrical communication with each of the plurality of side-by-side pouch battery modules 20. The voltage and temperature sensing board 90 may optionally measure the voltage from each battery grouping and the temperature at several locations. These signals may then be communicated to a main battery pack management unit (not shown) for processing.

[0027] like Figure 4As shown, a pair of battery pack modules 10 of the present invention can be positioned side by side with a cooling plate 100 located between the pair of devices. The cooling plate 100 functions similarly to the brackets 22 and 24 described above and can be made of one or more of the same materials. The cooling plate 100 can optionally be made of aluminum with a coolant circulated therein. There is sufficient thermal interface material between the cooling plate and the module to transfer heat from the module to the cooling plate. Figure 4 The advantage of the embodiment of the present system shown is only that it provides a Figure 1 The single embodiment shown has more power (and meets the voltage range requirements). The modularity of the present design provides advantages such as various numbers of pouch cell modules 20 can be stacked in each battery pack module 10 and various numbers of battery pack modules 10 can be further stacked together. For example, Figure 5 As shown, multiple Figure 4 The four systems shown can be positioned together on top of the battery pack bottom housing 120. Finally, as Figure 6 As shown, a plurality of battery modules 10 may be positioned together as a flat floor battery group that may be positioned in the chassis of an electric vehicle.

Claims

1. A battery pack module, comprising: Pouch cell battery module, including: First battery; a second battery; and an insulating pad disposed between the first battery and the second battery; a bus bar electrically connected to the pouch battery module; A first tab extending in a first direction away from the first battery; and The second tab comprises: A first portion extending across the insulating pad away from the second battery in two directions to contact the first tab; and The second portion extends from the first portion along the first direction away from the insulating pad to contact the bus bar.

2. The battery pack module according to claim 1, wherein: The insulating mat is thermally coupled to the first battery and the second battery and is configured to remove heat from each of the first battery and the second battery.

3. The battery pack module according to claim 1, wherein: The first tab and the second tab are ultrasonically welded together.

4. The battery pack module according to claim 1, further comprising: a third tab extending away from the first battery in a third direction opposite to the first direction; as well as A fourth tab extends along the third direction away from the second battery.

5. The battery module according to claim 4, wherein: The third tab and the fourth tab are coupled together. 6 . The battery pack module of claim 1 , further comprising a control board in electrical communication with the pouch battery module.

7. The battery module according to claim 6, wherein: The control board is configured to monitor voltage and temperature of the pouch battery module.

8. The battery module according to claim 1, further comprising: First bracket; as well as A second bracket, wherein the first battery and the second battery are disposed between the first bracket and the second bracket.

9. The battery module according to claim 1, wherein: The first tab extends across the insulating pad to contact the second tab.

10. The battery module according to claim 1, wherein: The second direction is perpendicular to the first direction.

11. A battery module, comprising: Busbar; as well as A plurality of pouch battery modules are electrically connected to the busbar, each of the plurality of pouch battery modules comprising: First battery; Second battery; an insulating pad disposed between the first battery and the second battery; A first tab extending in a first direction away from the first battery; and The second tab comprises: a first portion extending across the insulating pad in a second direction away from the second battery to contact the first tab; and The second portion extends from the first portion along the first direction away from the insulating pad to contact the bus bar.

12. The battery module according to claim 11, wherein: The insulating mat is thermally coupled to the first battery and the second battery and is configured to remove heat from each of the first battery and the second battery.

13. The battery module according to claim 11, wherein: The first tab and the second tab are ultrasonically welded together.

14. The battery module according to claim 11, further comprising: a third tab extending away from the first battery along a third direction opposite to the first direction; as well as A fourth tab extends along the third direction away from the second battery.

15. The battery module according to claim 14, wherein: The third tab and the fourth tab are coupled together. 16 . The battery pack module of claim 11 , further comprising a control board in electrical communication with each of the plurality of pouch battery modules.

17. The battery module according to claim 16, wherein: The control board is configured to monitor a voltage and a temperature of each of the plurality of pouch type battery modules.

18. The battery module according to claim 11, further comprising: First bracket; as well as A second bracket, wherein the first battery and the second battery are disposed between the first bracket and the second bracket. 19 . The battery module of claim 11 , wherein the first tab extends across the insulating pad to contact the second tab.

20. The battery module according to claim 11, wherein: The second direction is perpendicular to the first direction.

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