CN216563355U

CN216563355U - Battery core, battery module and battery pack

Info

Publication number: CN216563355U
Application number: CN202122998464.4U
Authority: CN
Inventors: 黄亚明; 文娟·刘·麦蒂斯; 赵文明; 凌一忱
Original assignee: Microvast Power Systems Huzhou Co Ltd
Current assignee: Microvast Power Systems Huzhou Co Ltd
Priority date: 2021-11-26
Filing date: 2021-11-26
Publication date: 2022-05-17
Anticipated expiration: 2031-11-26

Abstract

The utility model provides a battery cell, which is provided with a tab, wherein the tab is provided with a first coating, and the first coating is a fireproof insulating coating. According to the utility model, the fireproof insulating coating is arranged on the tab of the battery cell, and when the battery cell is out of control due to heat, the fireproof insulating coating can play a role in heat insulation, so that the influence of the out-of-control battery cell on surrounding normal battery cells is reduced, and the safety of vehicles and personnel is ensured. The utility model also provides a battery module and a battery pack.

Description

Battery core, battery module and battery pack

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery core, a battery module and a battery pack.

Background

The power battery has the advantages of high voltage, high specific energy, good cycle performance, cleanness, no pollution and the like, and is widely applied to the field of electric automobiles. With the increasing market demand for high energy density power battery systems, the safety requirements for power batteries are also increasing. However, the conventional power battery module of the electric vehicle is designed mostly due to the requirements of convenience of assembly and welding processes, safety design of electrical protection and light weight, and the design of thermal runaway safety protection between battery cells and between modules is insufficient. Especially, in case of a power battery system with high energy density, the battery cell inside the battery module is triggered to lose control of heat due to the problems of short circuit, extrusion, overcharge and the like, the diffusion speed of the battery cell is relatively high, and the safety of vehicles and personnel can be endangered.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an electric core, a battery module and a battery pack.

The inventor researches and discovers that after the battery core is broken due to thermal runaway, the generated high-temperature jet has conductivity, and the conductivity of the high-temperature jet can cause the occurrence of a complex short circuit phenomenon inside the battery pack and further cause the damage of other battery cores while generating a bad influence on the thermal environment of the battery core in the peripheral area. The action of the high temperature jet on both high temperature and electrical conductivity leads to rapid thermal runaway. At present, in the market, the thermal runaway expansion suppression scheme for the battery pack mostly only considers the heat wave released after the thermal runaway of the single-chip battery cell and the peripheral battery cells, but does not consider the influence caused by the conductive spray.

According to the battery cell provided by the utility model, the first coating is a fire-resistant insulating coating arranged on the lug of the battery cell, when the battery cell is subjected to thermal runaway rupture, a high-temperature conductive spray can be generated, and the fire-resistant insulating coating can play a heat-insulating effect, can block the influence of the high-temperature conductive spray on the surrounding normal battery cells, and can prevent the surrounding normal battery cells from being influenced to generate short circuit, so that the further diffusion of the thermal runaway is prevented, and the safety of vehicles and personnel is ensured.

An embodiment of the utility model provides a battery cell, which is provided with a tab, wherein a first coating is arranged on the tab, and the first coating is a fire-resistant insulating coating.

In an implementable manner, the outer surface of the cell is provided with a second coating, which is a refractory coating or a refractory insulating coating.

In one achievable form, the first coating and/or the second coating has a thickness of 0.1 to 0.8mm, or 0.2 to 0.5 mm.

Another embodiment of the present invention provides a battery module, including the battery cell described above.

In an implementable manner, the battery module further includes a first bus bar, the tab is connected with the first bus bar, and the surface of the first bus bar is provided with the first coating.

In an implementation manner, the battery module further includes a grid plate, the grid plate is located between the electric core and the first busbar, a grid is arranged on the grid plate, and the tab passes through the grid and then is connected to the first busbar; the grid plate is a refractory insulating grid plate.

In an implementable manner, the cell is formed with a first gap between a side of the cell adjacent to the grid plate and the grid plate, the first gap being filled with a refractory insulating filler.

In an implementable manner, a second void is formed between the grid and the tab, the refractory insulating filler being disposed within the second void.

Another embodiment of the present invention provides a battery pack including the above battery module.

In an implementation manner, the battery pack further comprises a second bus bar, the second bus bar is connected with the battery module, the outer surface of the second bus bar is provided with a third coating, and the third coating is a fire-resistant insulating coating.

In an implementable manner, the number of the battery modules is plural, the second bus bar includes a total positive bus bar, a total negative bus bar, and a connection bus bar for connecting the first bus bars of the plurality of the battery modules, and an outer surface of at least one of the total positive bus bar, the total negative bus bar, and the connection bus bar is provided with the third coating layer.

In one achievable form, the third coating has a thickness of 0.1 to 0.8mm, or 0.2 to 0.5 mm.

According to the battery cell provided by the utility model, the first coating is a fire-resistant insulating coating arranged on the lug of the battery cell, when the battery cell is out of control due to heat, a high-temperature conductive spray can be generated, and the fire-resistant insulating coating can play a heat-insulating and insulating effect, can block the influence of the high-temperature conductive spray on the surrounding normal battery cells, and can prevent the surrounding normal battery cells from being influenced to generate short circuit, so that the further diffusion of the out of control due to heat is prevented, and the safety of vehicles and personnel is ensured. In addition, also set up fire-resistant insulating coating in the battery module that this application provided and the battery package part, also can block the influence of electric conductivity high temperature jet to normal electric core around to prevent thermal runaway's further diffusion, guarantee vehicle and personnel's safety.

Drawings

Fig. 1 is a schematic structural diagram of a battery cell in an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a battery module according to an embodiment of the utility model.

Fig. 3 is a schematic structural diagram of the grid plate in fig. 2.

Fig. 4 is a schematic structural diagram of the first bus bar in fig. 2.

Fig. 5 is a schematic structural diagram of a battery pack according to an embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the utility model but are not intended to limit the scope of the utility model.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

The terms of orientation, up, down, left, right, front, back, top, bottom, and the like (if any) referred to in the specification and claims of the present invention are defined by the positions of structures in the drawings and the positions of the structures relative to each other, only for the sake of clarity and convenience in describing the technical solutions. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

As shown in fig. 1, an embodiment of the present invention provides an electric core 11, where the electric core 11 is provided with a tab 112, and a first coating (not shown) is provided on the tab 112, where the first coating is a fire-resistant insulating coating, and the first coating has a fire-resistant insulating function.

Specifically, through set up first coating on utmost point ear 112 at electric core 11, first coating is fire-resistant insulating coating, when electric core 11 takes place the thermal runaway, can produce the high temperature jet that has electric conductivity, and this fire-resistant insulating coating can play thermal-insulated insulating effect, can block the influence of electric conductivity high temperature jet to normal electric core 11 on every side, avoids normal electric core 11 on every side to receive the influence and take place the short circuit to prevent the further diffusion of thermal runaway.

Specifically, the range of the first coating layer disposed on the tab 112 is: the first coating layer is provided on all surfaces of the tab 112 except for a region for connection with the first bus bar 13 described below. The tab 112 and the first bus bar 13 are usually welded to ensure electrical conduction (although other connection methods can be adopted, which is only exemplified by welded connection), and the surface of the connection region is usually not provided with the first coating layer because the first coating layer has insulation property and affects electrical conductivity to ensure electrical conduction. In addition, this region is covered by the first bus bar 13 after connection, so that there is no longer any possibility of short-circuiting the connection region by contact with the high-temperature spray.

In one embodiment, the outer surface of the battery cell 11 is provided with a second coating (not shown), and the second coating is a fire-resistant coating or a fire-resistant insulating coating, and the second coating has a heat-insulating and fire-resistant function or a heat-insulating and fire-resistant function.

In one embodiment, the first coating layer and the second coating layer have a thickness of 0.2 to 0.5 mm. Under this thickness range, both can ensure the thermal-insulated fire-resistant/insulating function of first coating and second coating, can not influence the installation of electricity core 11 in the module again because of too thick.

In one embodiment, the battery cell 11 includes a casing 111, and the second coating is coated on an outer surface of the casing 111 by spraying.

Specifically, when the battery cell 11 is a soft-package battery cell, the casing 111 of the battery cell 11 is an aluminum-plastic film casing; when the battery cell 11 is a square battery cell or a cylindrical battery cell, the casing 111 of the battery cell 11 is an aluminum casing or a steel casing. Through setting up the second coating at the surface of the casing 111 of electric core 11, after electric core 11 takes place the thermal runaway, the fire-resistant coating on this emergence thermal runaway's electric core 11's casing 111 surface and the fire-resistant coating on adjacent electric core 11's casing 111 surface can play thermal-insulated effect jointly to reduce the temperature influence of out of control electric core 11 to normal electric core 11 on every side.

As shown in fig. 2, an embodiment of the present invention further provides a battery module, which includes the battery cell 11 described above.

As shown in fig. 1 and fig. 2, as an embodiment, the battery module 1 further includes a first bus bar 13, the first bus bar 13 is located on one side of the battery cell 11, the tab 112 is connected to the first bus bar 13, and a surface of the first bus bar 13 is also provided with a first coating.

In one embodiment, the first coating is disposed on an end surface of the first bus bar 13 on a side away from the battery cells 11.

As another embodiment, the first coating layer is disposed on all surfaces of the first bus bar 13, that is, in this embodiment, the first coating layer is in a state of entirely covering the tab 112 and the surface of the first bus bar 13.

As shown in fig. 2 to 4, as an embodiment, the battery module 1 further includes a grid plate 15, the grid plate 15 is a fire-resistant insulating grid plate, the grid plate 15 is located between the electric core 11 and the first bus bar 13, a grid 152 is disposed on the grid plate 15, a through hole 131 is disposed on the first bus bar 13, and the tab 112 sequentially passes through the grid 152 and the through hole 131 and then is connected to the first bus bar 13 by welding.

Specifically, grid plate 15 is mica grid plate, and it can play the effect of fixed electric core 11 and first busbar 13, simultaneously because its material is mica plate, mica plate has fire-resistant high temperature resistant and insulating characteristic, when electric core 11 takes place the thermal runaway, electric core 11 can show to rise or even catch fire in the temperature of utmost point ear 112 position department, and mica grid plate can bear high temperature and flame impact, can block the influence of electric conductivity high temperature jet to normal electric core 11 on every side, prevents the further diffusion of heat and flame.

As shown in fig. 2, a first gap 151 is formed between the grid plate 15 and the end of the cell 11 close to the grid plate 15, and a refractory insulating filler (not shown) is disposed in the first gap 151. Meanwhile, a second gap (not shown) is formed between the grid 152 and the tab 112 (in order to facilitate the tab 112 to pass through the grid 152, the size of the grid 152 is generally larger than that of the tab 112, so a gap is formed between the grid 152 and the tab 112), and a refractory insulating filler is also disposed in the second gap. The fire-resistant insulating filler can be attached to the surface of the tab 112 not in contact with the first bus bar 13, and the material of the fire-resistant insulating filler can be the same as that of the first coating, so that all exposed conductive parts (the tab 112 and the first bus bar 13) of the battery module 1 are covered by the fire-resistant insulating coating.

In particular, through experimental research, the reason for thermal runaway expansion of the power battery is not pure heat conduction. After the single-chip battery cell 11 is broken due to thermal runaway, the generated high-temperature spray has electrical conductivity, and besides the high-temperature spray affecting the surrounding battery cells 11 due to the high temperature, the electrical conductivity of the high-temperature spray also causes a complex short circuit phenomenon inside the battery pack, so that the damage of other battery cells 11 is further aggravated, namely, the thermal runaway is rapidly expanded due to the combined action of the characteristics of the high-temperature spray and the electrical conductivity of the high-temperature spray. In this embodiment, after a thermal runaway occurs in a certain electrical core 11, the released high-temperature conductive spray is isolated and insulated by the first coating and the refractory insulating filler, so as to avoid causing a high-voltage short circuit of systems of other electrical cores 11, and simultaneously, in combination with the thermal insulation effect of the second coating on the outer surface of the electrical core 11, both the thermal factor and the electrical factor causing the thermal runaway expansion of the power battery are effectively controlled.

As shown in fig. 2, as an embodiment, the number of the battery cells 11 is multiple, the multiple battery cells 11 are arranged in sequence, and adjacent battery cells 11 are connected by a first bus bar 13.

As shown in fig. 1 and fig. 2, as an embodiment, tabs 112 are disposed at two opposite ends of the battery cell 11, and the first busbar 13 and the grid plate 15 are disposed at two opposite ends of the battery cell 11, respectively, wherein the first busbar 13 at one end is connected to the tab 112 at one end of the battery cell 11, and the first busbar 13 at the other end is connected to the tab 112 at the other end of the battery cell 11.

As shown in fig. 5, an embodiment of the present invention further provides a battery pack, including the battery module 1 described above.

As shown in fig. 5, as an embodiment, the battery pack further includes a second bus bar 2, the second bus bar 2 is connected to the battery module 1, a third coating (not shown) is disposed on an outer surface of the second bus bar 2, the third coating is a fire-resistant insulating coating, the third coating has functions of heat insulation, fire resistance and insulation, and a material of the third coating may be the same as a material of the first coating.

As shown in fig. 5, as an embodiment, the number of the battery modules 1 is plural, the plurality of battery modules 1 are arranged in sequence, the second bus bar 2 includes a total positive bus bar 21, a total negative bus bar 22, and a connection bus bar 23 for connecting the first bus bars 13 of the plurality of battery modules 1, the total positive bus bar 21 and the total negative bus bar 22 are used for connecting an external circuit, and the total positive bus bar 21, the total negative bus bar 22, and the connection bus bar 23 are all copper bars. The outer surfaces of the total positive bus bar 21, the total negative bus bar 22 and the connecting bus bar 23 are all provided with third coatings, so that the problem of short circuit between modules caused by high-temperature conductive spray when the single battery cell 11 is out of control due to heat is avoided.

In one embodiment, the third coating has a thickness of 0.2 to 0.5 mm. Under the thickness range, the heat insulation function of the third coating can be guaranteed, and the installation of the battery module 1 in the battery pack cannot be influenced due to the excessive thickness.

The materials for the refractory insulating coating and the refractory insulating filler according to the present invention include, but are not limited to, refractory epoxy resin, refractory insulating ceramic particles, and the like.

The battery module provided by the embodiment of the utility model sets the second coating on the outer surface of the shell 111 of the battery cell 11, the second coating is a fire-resistant coating, when the battery cell 11 is out of thermal runaway, the fire-resistant coating on the surface of the shell 111 of the battery cell 11 out of thermal runaway and the fire-resistant coating on the surface of the shell 111 of the adjacent battery cell 11 can jointly play a heat insulation effect, so that the temperature influence of the battery cell 11 out of thermal runaway on the surrounding normal battery cells is reduced. Meanwhile, a first coating is arranged on a tab 112 of the battery cell 11, a first coating is also arranged on the surface of the first busbar 13, a fireproof insulating filler is arranged in a first gap 151 between the battery cell 11 and the grid plate 15 and a second gap between the grid 152 and the tab 112, and a third coating is arranged on the outer surface of the second busbar 2, i.e., the whole battery cell 11, the battery module 1 and the exposed and electrified parts of the battery pack (except for the parts needing to be electrically connected with each other) are all provided with the fireproof insulating coatings, so that the internal short circuit and the heat influence of the battery pack caused by high-temperature spray are blocked, the overall thermal runaway spreading speed of the battery pack is reduced, and the fireproof insulating coatings do not occupy redundant space, so that the energy density of the battery is not influenced.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The utility model provides an electric core, electric core (11) are equipped with utmost point ear (112), its characterized in that, be equipped with first coating on utmost point ear (112), first coating is fire-resistant insulating coating.

2. The electrical core according to claim 1, wherein the outer surface of the electrical core (11) is provided with a second coating, which is a fire resistant coating or a fire resistant insulating coating.

3. The cell of claim 2, wherein the first coating and/or the second coating has a thickness of 0.1 to 0.8 mm.

4. A battery module, characterized in that it comprises a cell (11) according to any one of claims 1 to 3.

5. The battery module according to claim 4, wherein the battery module (1) further comprises a first bus bar (13), the tab (112) is connected to the first bus bar (13), and a surface of the first bus bar (13) is provided with the first coating layer.

6. The battery module according to claim 5, wherein the battery module (1) further comprises a grid plate (15), the grid plate (15) is located between the battery cells (11) and the first bus bar (13), a grid (152) is arranged on the grid plate (15), and the tabs (112) penetrate through the grid (152) and then are connected with the first bus bar (13); the grid plate (15) is a refractory insulating grid plate.

7. The battery module according to claim 6, wherein a first gap (151) is formed between the grid plate (15) and the cell (11) on the side close to the grid plate (15), and a refractory insulating filler is disposed in the first gap (151).

8. The battery module according to claim 6 or 7, wherein a second gap is formed between the grid (152) and the tab (112), and the refractory insulating filler is provided in the second gap.

9. A battery pack characterized by comprising the battery module (1) according to any one of claims 4 to 8.

10. The battery pack according to claim 9, further comprising a second bus bar (2), wherein the second bus bar (2) is connected to the battery module (1), and wherein a third coating layer is provided on an outer surface of the second bus bar (2), and wherein the third coating layer is a fire-resistant insulating coating layer.

11. The battery pack according to claim 10, wherein the number of the battery modules (1) is plural, the second bus bar (2) includes a total positive bus bar (21), a total negative bus bar (22), and a connection bus bar (23) for connecting the first bus bars (13) of the plurality of battery modules (1), and an outer surface of at least one of the total positive bus bar (21), the total negative bus bar (22), and the connection bus bar (23) is provided with the third coating layer.

12. The battery pack according to any one of claims 10 or 11, wherein the third coating layer has a thickness of 0.1 to 0.8 mm.