Integrated busbar with exhaust channel and battery module

Abstract

The utility model discloses an integrated busbar with an exhaust channel, comprising an electrical isolation board (1), the electrical isolation board (1) is connected with a busbar (2) and a voltage and temperature signal acquisition board (3), the electrical isolation board (1) is provided with an exhaust channel (4) corresponding to a cell explosion-proof valve (7), and the width of the exhaust channel (4) is greater than that of the cell explosion-proof valve (7). The length of the exhaust channel (4) covers all the battery cells (9) along the arrangement direction of the battery cells (9), the section of the exhaust channel (4) is U-shaped, and the exhaust channel (4) is connected with a high-temperature-resistant layer (5) along the length direction corresponding to the battery cell explosion-proof valve (7). According to the utility model, gas can be consistently discharged when the battery cell is in thermal runaway, so that the safety of a battery pack system is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and in particular relates to an integrated busbar and a battery module with an exhaust channel. Background Art

[0002] The battery module is composed of multiple single cells connected by a bus. Aerogel is provided on the outside of the outermost cells at both ends, which are used for connection, fixation, heat insulation and electrical safety insulation. There is usually an integrated busbar welded and fixed to the cell pole end. The integrated busbar assembly is usually composed of an isolation plate, a busbar, a voltage and temperature signal acquisition board, and its main function is to collect voltage and temperature and transmit current for the module cells. Its advantages are simple structural design, low cost, excellent process feasibility and high production efficiency.

[0003] If the actual operating conditions of the battery cell (such as temperature limit, voltage limit, current limit, etc.) are not dynamically adjusted to match them, there will be a risk of accelerated damage to the internal structure of the battery cell and accelerated failure of some key raw materials. This is mainly manifested in chemical reactions inside the battery cell, internal short circuits, and the generation of a large amount of flammable gas. As the temperature rises sharply, the gas inside the battery cell reaches a certain pressure, which in turn causes the puncture of the battery cell's explosion-proof valve, and then discharges high-temperature flammable gas and charged lithium ions to the outside. If there are conductive objects or materials with a low melting point around the battery cell's explosion-proof valve, it may directly cause fire, explosion, and other phenomena. Most of the existing integrated busbar solutions are that the battery cell explosion-proof valve and the electrical isolation plate are not completely isolated or the electrical isolation plate material used has a low melting point. The melting point of commonly used plastic materials is mostly around 110°C. After thermal runaway occurs, the high-temperature gas discharged from the lithium iron phosphate battery cell is about 500°C or above, and the temperature of the ternary battery cell is even higher, about 800°C or above. Therefore, when thermal runaway occurs, due to the high internal pressure of the battery cell, fast exhaust rate, and high temperature, it is very easy to cause the electrical isolation plate to fail. The high-temperature gas and charged lithium ions discharged from the battery cell flow randomly and irregularly inside the battery pack, quickly causing safety hazards and accidents. Therefore, it is urgent to take effective measures for the gas discharge path of the battery cell explosion-proof valve and the thermal protection scheme to avoid or reduce the probability of safety accidents caused by thermal runaway as much as possible. Utility Model Content

[0004] The purpose of the utility model is to provide an integrated busbar and battery module with an exhaust channel, which can maintain consistent gas discharge when the battery cell thermal runaways, thereby improving the safety of the battery pack system.

[0005] To achieve the above object, the integrated busbar of the present utility model with an exhaust passage includes an electrical isolation plate, a busbar and a voltage and temperature signal acquisition board are connected to the electrical isolation plate. An exhaust passage is provided on the electrical isolation plate corresponding to the explosion-proof valve of the battery cell. The width of the exhaust passage is greater than the width of the explosion-proof valve of the battery cell. The length of the exhaust passage covers all the battery cells along the arrangement direction of the battery cells. The cross-section of the exhaust passage is U-shaped, and a high-temperature resistant layer is connected to the exhaust passage corresponding to the explosion-proof valve of the battery cell along the length direction.

[0006] As a further solution of the present utility model: the depth of the exhaust passage is greater than 4.5 mm.

[0007] As a further solution of the present utility model: the thickness of the high-temperature resistant layer is less than or equal to 1.5 mm.

[0008] To achieve the above object, on the other hand, the present utility model provides a battery module, which includes a battery pack composed of a plurality of juxtaposed battery cells, and also includes the above integrated busbar with an exhaust passage, and is connected to the end of the battery pack in alignment.

[0009] As a further solution of the present utility model: adjacent battery cells are connected and fixed by a hot melt pressure-sensitive adhesive.

[0010] As a further solution of the present utility model: the hot melt pressure-sensitive adhesive has an annular structure.

[0011] As a further solution of the present utility model: a heat insulation pad is connected to the surface of the outermost battery cell.

[0012] As a further solution of the present utility model: a temperature plate is connected to the bottom of the battery pack.

[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0014] 1) When designing the electrical isolation plate, a special exhaust passage for gas is considered. When the battery cell is thermally out of control, exhaust gas and electrolyte can be discharged according to the exhaust passage, and finally the gas can be effectively discharged to the outside through the explosion-proof valve of the battery pack, improving the safety of the battery pack system;

[0015] 2) A high-temperature resistant layer is arranged on the side directly opposite to the explosion-proof valve of the battery cell, which can effectively prevent high-temperature and high-pressure gas from directly impacting the exhaust passage, thereby causing its deformation and damage and affecting the exhaust effect;

[0016] 3) A temperature plate is added to the bottom of the battery pack. Through the refrigeration method, the high-temperature gas inside the battery cell can be quickly taken away to achieve the purpose of rapid heat exchange;

[0017] 4) A heat insulation pad is arranged on the surface of the outermost battery cell, which can ensure the consistency of the surface temperature of all the battery cells in the battery module and improve the service life of the battery cells;

[0018] 5) The cells are fixed to each other using a hot-melt pressure-sensitive adhesive. The hot-melt pressure-sensitive adhesive is in a ring structure, which can be used to absorb the size change of the cells after expansion, extend the service life of the cells, and at the same time ensure the mechanical properties of the battery module itself and the hoisting and transportation conditions of the battery module. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the integrated busbar with an exhaust channel of the present utility model.

[0020] Figure 2 is a schematic structural diagram of the battery module of the present utility model.

[0021] Figure 3 is an exploded structural diagram of the battery module of the present utility model.

[0022] Figure 4 is a partial cross-sectional view of the battery module of the present utility model.

[0023] In the figure: 1, electrical isolation plate; 2, busbar; 3, voltage and temperature signal acquisition board; 4, exhaust channel; 5, high-temperature resistant layer; 6, temperature plate; 7, cell explosion-proof valve; 8, heat insulation pad; 9, cell; 10, hot-melt pressure-sensitive adhesive. Detailed Embodiment

[0024] The present utility model will be further described below with reference to the accompanying drawings.

[0025] As Figure 1 and Figure 4 shown, the integrated busbar with an exhaust channel includes an electrical isolation plate 1. A busbar 2 and a voltage and temperature signal acquisition board 3 are connected to the electrical isolation plate 1. An exhaust channel 4 is provided on the electrical isolation plate 1 corresponding to the cell explosion-proof valve 7. The width of the exhaust channel 4 is greater than the width of the cell explosion-proof valve 7. The length of the exhaust channel 4 covers all the cells 9 along the arrangement direction of the cells 9. The cross-section of the exhaust channel 4 is U-shaped. A high-temperature resistant layer 5 is connected to the exhaust channel 4 corresponding to the cell explosion-proof valve 7 along the length direction.

[0026] Providing the exhaust channel 4 on the electrical isolation plate 1 is beneficial to the consistent discharge of the high-temperature and high-pressure gas ejected when the cell explosion-proof valve 7 of the cell 9 opens during thermal runaway. The setting of the high-temperature resistant layer 5 can prevent the high-temperature and high-pressure gas from directly impacting the exhaust channel 4, causing damage such as deformation and melting of the exhaust channel 4, thereby improving the safety of the battery pack system.

[0027] Furthermore, the depth of the exhaust channel 4 is greater than 4.5 mm, considering the placement of the high-temperature resistant layer 5 and reserving enough air flow paths.

[0028] Furthermore, the thickness of the high-temperature resistant layer 5 is less than or equal to 1.5 mm, which can avoid occupying too much space of the exhaust passage 4 while playing a role in protecting the exhaust passage 4 from high temperature. The material selection of the high-temperature resistant layer is not limited to high-temperature ceramic fireproof cloth, aerogel, ceramic silica gel strip, fiberglass cloth, high-temperature resistant PU foam, etc. The high-temperature resistance requirement of the material is greater than 800 °C, and the thermal conductivity is less than 0.02 W / m·K.

[0029] As Figure 2 and Figure 3 shown, the present utility model also provides a battery module, which includes a battery pack composed of a plurality of juxtaposed battery cells 9, and also includes the above-mentioned integrated busbar with an exhaust passage 4, which is connected to the end of the battery pack in alignment.

[0030] The high-temperature and high-pressure gas ejected from the explosion-proof valve 7 of the battery cell can be guided and constrained by the exhaust passage 4, and finally effectively discharged outwards through the explosion-proof valve of the battery pack, avoiding the random and irregular flow of high-temperature gas inside the battery pack and improving the safety of the battery pack system.

[0031] In order to improve the mechanical performance of the battery module itself and the hoisting and transportation conditions after the battery cells are grouped, further, the adjacent battery cells 9 are connected and fixed by a hot-melt pressure-sensitive adhesive 10, and the mechanical strength requirement of the hot-melt pressure-sensitive adhesive 10 is greater than 6 MPa.

[0032] Furthermore, the hot-melt pressure-sensitive adhesive 10 is in an annular structure, and the gluing range is to be smeared inward along the outer contour of the battery cell 9, with a width of 10 - 15 mm and a thickness of 0.2 - 0.5 mm. The middle area can be used to absorb the size after the expansion of the battery cell 9, thereby extending the service life of the battery cell 9.

[0033] In order to ensure the consistency of the surface temperature of the battery cells 9 in the battery module, further, the surface of the outermost battery cell 9 is connected with a heat insulation pad 8, and the heat insulation pad 8 can be made of materials with a thermal conductivity less than 0.02 W / m·K such as aerogel and PU foamed silica gel, and the thickness is determined according to the designed reserved assembly dimension.

[0034] Furthermore, a temperature plate 6 is connected to the bottom of the battery pack, which can be a liquid-cooled stamping plate, a refrigerant stamping plate, etc. Refrigeration can be carried out through the temperature plate 6 to take away the high temperature inside the battery cell 9, so as to achieve the purpose of rapid heat exchange. According to the external environment conditions, when necessary, the battery cell 9 can also be heated to make the battery cell 9 meet the normal working requirements.

Claims

1. An integrated busbar with an exhaust channel, comprising an electrical isolation plate (1), to which a busbar (2) and a voltage and temperature signal acquisition board (3) are connected, characterized in that: An exhaust channel (4) is provided on the electrical isolation plate (1) corresponding to the battery cell explosion-proof valve (7); the width of the exhaust channel (4) is greater than the width of the battery cell explosion-proof valve (7); the length of the exhaust channel (4) covers all the battery cells (9) along the arrangement direction of the battery cells (9); the cross section of the exhaust channel (4) is U-shaped; and a high temperature resistant layer (5) is connected to the exhaust channel (4) along the length direction corresponding to the battery cell explosion-proof valve (7).

2. The integrated busbar with exhaust channel according to claim 1, characterized in that: The exhaust channel (4) has a depth greater than 4.5 mm.

3. The integrated busbar with exhaust channel according to claim 2, characterized in that: The thickness of the high temperature resistant layer (5) is less than or equal to 1.5 mm.

4. A battery module, comprising a battery pack consisting of a plurality of battery cells (9) arranged in parallel, characterized in that: It also includes an integrated busbar with an exhaust channel as described in any one of claims 1 to 3, and is connected to the end of the battery pack in an aligned manner.

5. The battery module according to claim 4, characterized in that: Adjacent battery cells (9) are connected and fixed by hot-melt pressure-sensitive adhesive (10).

6. The battery module according to claim 5, characterized in that: The hot melt pressure sensitive adhesive (10) is in a ring structure.

7. The battery module according to claim 4 or 5, characterized in that: A heat insulation pad (8) is connected to the surface of the outermost battery core (9).

8. The battery module according to claim 7, characterized in that: A temperature plate (6) is connected to the bottom of the battery pack.

Images