Battery pack and electric device

Abstract

A battery pack and an electric device. The battery pack comprises a support plate (230), a bottom protective plate (250) and a plurality of battery cells (100), wherein a pressure relief valve (110) is provided at the bottom of each battery cell (100); the plurality of battery cells (100) are placed on the support plate (230), and the support plate (230) is provided with pressure relief holes (231) corresponding to the pressure relief valves (110); the bottom protective plate (250) covers the end surface of the support plate (230) away from the battery cells (100); a plurality of separation ribs (251) are provided between the bottom protective plate (250) and the support plate (230); the separation ribs (251), the support plate (230) and the bottom protective plate (250) enclose a liquid-cooling flow channel (252), and the separation ribs (251), the bottom protective plate (250) and the pressure relief holes (231) enclose a pressure relief channel (240); and the liquid-cooling flow channel (252) is in heat-exchange connection with the pressure relief channel (240).

Description

Battery packs and electrical devices

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 29, 2024, with application number 202422392425.3. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, for example, to a battery pack and an electrical device. Background Art

[0003] Lithium-ion batteries, with their advantages of compact size, high energy density, long cycle life, and extended storage life, have been widely used in a variety of electronic devices, electric vehicles, and electric toys. Conventional battery pack designs typically place the pressure relief valve and positive and negative tabs on the same side of the prismatic cell, located on the top cover of the cell. Technical issues

[0004] Since the pressure relief valve and positive and negative tabs of the square battery cell are all located on the top cover of the battery cell, when the square battery cell experiences thermal runaway, the high-temperature flame ejected from the battery cell pressure relief valve usually easily burns the battery pack's battery connection system (CCS), wiring harness, battery management system (BMS) and other live components. Some electrolyte that has not been fully burned will splash out and come into contact with the CCS bus, wiring harness, copper bus, etc., causing the battery pack to short-circuit and trigger a more serious secondary fire, thereby reducing the safety and reliability of the battery pack. Solution

[0005] The present application provides a battery pack that can ensure that when a battery cell experiences thermal runaway, the electrical components within the battery pack will not be affected, thereby enhancing the safety and reliability of the battery pack.

[0006] In the first aspect, an embodiment of the present application provides a battery pack, comprising: a support plate, a bottom guard plate and a plurality of battery cells, a pressure relief valve being provided at the bottom of the battery cells; a plurality of battery cells being placed on the support plate, and a pressure relief hole corresponding to the pressure relief valve being opened on the support plate; a bottom guard plate covering the end surface of the support plate away from the battery cells, a cavity being provided between the bottom guard plate and the support plate, and a plurality of partition ribs being provided in the cavity, the plurality of partition ribs dividing the cavity into a plurality of liquid cooling channels, the partition ribs, the bottom guard plate and the pressure relief hole being enclosed in a pressure relief channel, and the liquid cooling channel being connected to the pressure relief channel for heat exchange.

[0007] In a second aspect, an embodiment of the present application provides an electrical device, which includes a battery pack as described in any of the above solutions. Beneficial effects

[0008] The battery cell in the battery pack has a pressure relief valve at the bottom, and the flame, high-temperature gas and electrolyte generated inside the battery cell during thermal runaway are sprayed downward through the bottom to avoid affecting the electrical components set on the top of the battery cell, thereby avoiding short circuit and damage to the electrical connectors of the battery pack; the battery cell is placed on a support plate, and a bottom guard plate covers the bottom of the support plate. A dividing rib is provided between the bottom guard plate and the support plate, so that a liquid cooling channel is formed between the bottom guard plate and the support plate through the dividing rib, and the support plate is provided with a pressure relief hole corresponding to the pressure relief valve, and the pressure relief hole and the dividing rib are formed into a pressure relief channel, and the high-temperature gas and flame generated when the battery cell is thermal runaway are discharged outward from the pressure relief channel. The liquid cooling channel cools the battery cell on the one hand, and can also cool the high-temperature gas in the pressure relief channel on the other hand, thereby avoiding heat diffusion caused by the high temperature generated when the battery cell is thermal runaway, thereby improving the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is an axonometric view of a battery cell provided in a specific embodiment of the present application;

[0010] FIG2 is an axonometric view of a battery pack according to an embodiment of the present application;

[0011] FIG3 is an axonometric view of a battery pack provided in a specific embodiment of the present application with some components hidden;

[0012] FIG4 is a partially enlarged perspective cross-sectional view of a module box provided in a specific embodiment of the present application;

[0013] FIG5 is a top view of a battery pack provided in a specific embodiment of the present application;

[0014] FIG6 is a cross-sectional view at AA in FIG5;

[0015] FIG7 is a partial enlarged view of point C in FIG6;

[0016] FIG8 is a cross-sectional view at BB in FIG5 ;

[0017] FIG9 is a partial enlarged view of point D in FIG8 .

[0018] In the picture:

[0019] 10. Battery cell group; 100. Battery cell; 110. Pressure relief valve; 120. Terminal; 130. Buffer pad;

[0020] 200. Module box; 210. End plate; 211. Explosion-proof valve; 212. Water pipe joint; 220. Side panel; 230. Support plate; 231. Pressure relief hole; 232. Fireproof pad; 233. Elastic pad; 2331. Avoidance hole; 234. Thermal conductive structural adhesive; 240. Pressure relief channel; 250. Bottom guard plate; 251. Separation rib; 252. Liquid cooling channel; 260. Baffle; 261. Electrical components. Modes for Carrying Out the Invention

[0021] The first direction described in this embodiment is the X direction shown in Figures 2, 3 and 6, that is, the length direction of the battery pack, and the second direction is the Y direction shown in Figures 2, 3 and 8, that is, the width direction of the battery pack.

[0022] As shown in Figures 1 to 4, the battery pack in this embodiment consists of a module case 200 and multiple battery cells 100 within the module case 200. The multiple battery cells 100 are stacked and arranged inside the module case 200. The module case 200 includes conventional components such as end plates 210 and side plates 220. In this embodiment, the top of a battery cell 100 refers to the end face of the battery cell 100 with the pole 120, and the bottom refers to the end face opposite the end face with the pole 120. The pressure relief valve 110 is provided on this bottom end face.

[0023] A buffer pad 130 is further sandwiched between two adjacent battery cells 100 to buffer pressure and squeeze the outer walls of the battery cells 100 to avoid lithium deposition and improve the safety and reliability of the battery cells 100.

[0024] As shown in Figures 3 to 9, the battery pack includes a support plate 230, a bottom guard plate 250 and multiple battery cells 100, and a pressure relief valve 110 is provided at the bottom of the battery cell 100; multiple battery cells 100 are placed on the support plate 230, and the support plate 230 is provided with a pressure relief hole 231 corresponding to the pressure relief valve 110; the bottom guard plate 250 covers the end surface of the support plate 230 away from the battery cell 100, and there is a cavity between the bottom guard plate 250 and the support plate 230, and a plurality of partition ribs 251 are provided in the cavity, and the partition ribs 251 divide the cavity into multiple liquid cooling channels 252, and the partition ribs 251, the bottom guard plate 250 and the pressure relief hole 231 are surrounded by a pressure relief channel 240, and the liquid cooling channel 252 is connected to the pressure relief channel 240 for heat exchange.

[0025] The battery cell 100 in the battery pack has a pressure relief valve 110 set at the bottom, through which the flame, high-temperature gas and electrolyte generated inside the battery cell 100 when thermal runaway is ejected downward to avoid affecting the electrical components 261 set on the top of the battery cell 100, thereby avoiding short circuit and damage to the electrical connectors of the battery pack; and the battery cell 100 is placed on the support plate 230, and the bottom guard plate 250 covers the bottom of the support plate 230. A separation rib 251 is set between the bottom guard plate 250 and the support plate 230, so that the bottom guard plate 250 and the support plate 230 are separated. A liquid cooling channel 252 is formed by the separating ribs 251, and the support plate 230 is provided with a pressure relief hole 231 corresponding to the pressure relief valve 110. The pressure relief hole 231 and the separating ribs 251 are surrounded by a pressure relief channel 240. The high-temperature gas and flame generated when the battery cell 100 thermally runs away are discharged outward from the pressure relief channel 240. The liquid cooling channel 252 cools the battery cell 100 on the one hand, and on the other hand, it can also cool the high-temperature gas in the pressure relief channel 240, thereby avoiding heat diffusion caused by the high temperature generated when the battery cell 100 thermally runs away, thereby improving the safety of the battery pack.

[0026] The plurality of battery cells 100 are electrically connected via a CCS, a wiring harness, a BMS, etc. The electrical components 261 herein refer to the CCS, the wiring harness, the BMS, etc.

[0027] As shown in Figures 3, 7, and 9, a fireproof pad 232 is sandwiched between the battery cell 100 and the support plate 230. The fireproof pad 232 can at least cover the pressure relief hole 231. When the battery cell 100 experiences thermal runaway, the high-temperature and high-pressure gas generated can break through the fireproof pad 232, and the pressure is released by the pressure relief channel 240, avoiding the accumulation of heat and pressure. At the same time, the setting of the fireproof pad 232 can also prevent the high-temperature and high-pressure gas generated during thermal runaway from damaging the corresponding battery cell 100 through other pressure relief holes 231, thereby preventing heat spread and heat diffusion, and improving the safety of the battery pack. In this embodiment, the fireproof pad 232 can be made of mica paper.

[0028] Optionally, an elastic pad 233 is attached to the top wall of the fireproof pad 232, and an avoidance hole 2331 is opened in the elastic pad 233 at the position corresponding to the pressure relief hole 231. As shown in Figure 2, the elastic pad 233 only covers the outer periphery of the pressure relief hole 231, and does not completely cover the bottom of the entire battery cell 100, thereby reducing the use of elastic parts. The provision of the elastic parts can keep the pressure relief hole 231 and the pressure relief valve 110 sealed from the internal environment of the battery pack, preventing damage to the pressure relief valve 110 at the bottom of the battery cell 100 when the battery cell 100 is fixed inside the battery pack.

[0029] In this embodiment, thermally conductive adhesive 234 is also filled between the battery cell 100 and the fireproof pad 232. This adhesive 234 secures the battery cell 100 within the battery pack and also provides good heat conduction. Furthermore, when the adhesive 234 is poured, the elastic member prevents it from contacting the pressure relief valve 110, improving safety and reliability. In this embodiment, the elastic member can be made of foam.

[0030] Referring back to Figures 3, 6, and 7, multiple battery cells 100 are stacked along a first direction to form a battery cell group 10. Separator ribs 251 extend along the first direction, and multiple pressure relief holes 231 are all connected to the same pressure relief channel 240. By extending the separator ribs 251 along the first direction, the pressure relief channel 240 also extends along the first direction. The corresponding multiple pressure relief holes 231 are spaced apart along the first direction. This facilitates stacking of the battery cells 100, minimizes the complexity of the shapes of the pressure relief channel 240 and the separator ribs 251, reduces production and manufacturing costs, and ensures unobstructed flow of the pressure relief channel 240.

[0031] Optionally, multiple groups of cell groups 10 are stacked along the second direction, with multiple pressure relief channels 240 spaced apart correspondingly, and the second direction is perpendicular to the first direction. In this embodiment, two groups of cell groups 10 are provided, and correspondingly, two pressure relief channels 240 are spaced apart along the second direction, each extending along the first direction. The number of pressure relief channels 240, pressure relief holes 231, cell groups 10, and cell units 100 can be adaptively adjusted based on specific needs.

[0032] As shown in Figures 4, 6, and 7, the battery pack also includes two end plates 210, which are disposed at either end of the battery cell group 10 along a first direction. At least one of the end plates 210 has a hollow structure, and the pressure relief channel 240 is connected to the hollow end plate 210. In this embodiment, the pressure relief channel 240 is connected to the hollow end plate 210 to discharge the high-temperature, high-pressure gas generated by thermal runaway of the battery cell 100 from the end plate 210. This eliminates the need for additional exhaust channels or ducts, thereby reducing the volume of the battery pack and improving its energy density.

[0033] Optionally, a baffle 260 is further provided between the end plate 210 and the cell pack 10. The baffle 260 and the end plate 210 provided with the explosion-proof valve 211 enclose an installation space, which is configured to accommodate electrical components 261. The provision of the baffle 260 separates the battery pack from the enclosed installation space, separating it from the space where the cell pack 10 is located. This prevents direct damage to the electrical components 261 within the installation space by high-temperature, high-pressure gases and flames generated by the battery cells 100, thereby improving the safety of the battery pack.

[0034] As shown in Figures 2, 3 and 9, a water pipe joint 212 is also provided on the end plate 210 for connecting the liquid cooling channel 252 with an external coolant storage device. Two water pipe joints 212 are provided to realize the circulation of the coolant inside the liquid cooling channel 252 and improve the heat dissipation and cooling effect.

[0035] As shown in Figures 6 and 8, the battery pack may also include two side plates 220, which are respectively arranged at both ends of the battery cell group 10 along the second direction. The two side plates 220 and the two end plates 210 are hollow structures. The two end plates 210 are connected to each other through the side plates 220. One of the two end plates 210 is connected to the above-mentioned pressure relief channel 240, and the other end plate 210 is provided with an explosion-proof valve 211. Through the above arrangement, when thermal runaway occurs in the battery cell 100, the high-temperature flue gas generated by it is discharged into the pressure relief channel 240 through the pressure relief hole 231, and then discharged along the pressure relief channel 240 to the interior of the end plate 210 connected thereto, and then discharged from the end plate 210 to the side plate 220 connected to the end plate 210, and finally discharged from the side plate 220 to another end plate 210 provided with an explosion-proof valve 211, thereby extending the flow path of the high-temperature flue gas, avoiding the pressure increase caused by the instantaneous accumulation of high-temperature flue gas due to a too short path, avoiding the rupture and damage of the module box 200 of the battery pack, and improving the safety and reliability of use; the explosion-proof valve 211 can exhaust and explode when the pressure of the high-temperature flue gas in the hollow structure of the end plate 210 and the side plate 220 is too high, thereby avoiding safety accidents.

[0036] Two explosion-proof valves 211 are provided, one corresponding to the two side panels 220 of the battery pack, to improve the explosion-proof effect.

[0037] The battery pack provided in this embodiment can ensure that when a battery cell experiences thermal runaway, it will not affect the electrical components within the battery pack, and can also avoid heat diffusion caused by the high temperature generated when the battery cell experiences thermal runaway, thereby improving the safety and reliability of the battery pack.

[0038] This embodiment also provides an electrical device comprising a battery pack as described in any of the above-described solutions. Specifically, the electrical device can be an electric vehicle, hybrid vehicle, electric ship, electric bicycle, energy storage device, or the like, requiring only the battery pack for power supply or energy storage. The use of the aforementioned battery pack in this electrical device ensures that thermal runaway of the battery cell 100 will not affect the electrical components 261 within the battery pack, thereby enhancing the safety and reliability of the battery pack and ensuring the safety of the electrical device.

Claims

1. A battery pack comprising: A plurality of battery cell units (100), wherein a pressure relief valve (110) is provided at the bottom of each battery cell unit (100); a support plate (230), wherein a plurality of the battery cell units (100) are placed on the support plate (230), and the support plate (230) is provided with a pressure relief hole (231) corresponding to the pressure relief valve (110); A bottom guard plate (250) covers the end surface of the support plate (230) away from the battery cell (100); a cavity is provided between the bottom guard plate (250) and the support plate (230); a plurality of partition ribs (251) are provided in the cavity; the plurality of partition ribs (251) divide the cavity into a plurality of liquid cooling channels (252); the partition ribs (251), the bottom guard plate (250) and the pressure relief hole (231) are arranged to form a pressure relief channel (240); the liquid cooling channel (252) is connected to the pressure relief channel (240) for heat exchange.

2. The battery pack according to claim 1, wherein: A fireproof pad (232) is further provided between the battery cell (100) and the support plate (230), and the fireproof pad (232) is at least capable of covering the pressure relief hole (231).

3. The battery pack according to claim 2, wherein: An elastic pad (233) is attached to the top wall of the fireproof pad (232), and an avoidance hole (2331) is opened at a position of the elastic pad (233) corresponding to the pressure relief hole (231).

4. The battery pack according to claim 3, wherein: A heat-conducting structural adhesive (234) is also filled between the battery cell (100) and the fireproof pad (232).

5. The battery pack according to claim 1, wherein: A plurality of the battery cell units (100) are stacked along a first direction to form a battery cell group (10), the separation ribs (251) are extended along the first direction, and the plurality of pressure relief holes (231) are all connected to the same pressure relief channel (240).

6. The battery pack according to claim 5, wherein: The battery cell groups (10) are stacked in a plurality of groups along a second direction, and the pressure relief channels (240) are arranged in a plurality at corresponding intervals, and the second direction is perpendicular to the first direction.

7. The battery pack according to claim 6, further comprising two end plates (210), the two end plates (210) being respectively arranged at two ends of the battery cell group (10) along the first direction, at least one of the end plates (210) being a hollow structure, and the pressure relief channel (240) being connected to the end plate (210) having the hollow structure.

8. The battery pack according to claim 7, further comprising two side plates (220), the two side plates (220) being respectively arranged at both ends of the battery cell group (10) along the second direction, the two side plates (220) and the two end plates (210) being hollow structures, the two end plates (210) being interconnected through the side plates (220), one of the two end plates (210) being arranged in communication with the pressure relief channel (240), and the other of the two end plates (210) being provided with an explosion-proof valve (211).

9. The battery pack according to claim 8, wherein: A baffle (260) is further provided between the end plate (210) and the battery cell group (10), and the baffle (260) and the end plate (210) provided with the explosion-proof valve (211) enclose an installation space, and the installation space is provided for installing electrical components (261).

10. An electrical device comprising the battery pack according to any one of claims 1 to 9.

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