Battery pack and energy storage device

Abstract

The utility model provides a battery pack and an energy storage device. The battery pack comprises a shell, and a battery module, a plurality of busbars and an insulated first isolation belt which are accommodated in the shell, the battery module comprises a plurality of battery cells arranged in the length direction of the battery pack, a plurality of busbars are arranged on the surface where the pole columns of the battery cells are located, and every two adjacent battery cells in the battery cells are electrically connected through one busbar in the busbars. The first isolation strip extends in the length direction of the battery pack and covers the surfaces, deviating from the battery cells, of the multiple busbars; and gaps exist between the first isolation belt and the pressure release valves of the plurality of battery cells in the interval direction of the pole columns and the pressure release valves. According to the application, the problems that in the thermal runaway process of the PACK, after designed insulation failure is caused by high temperature, a short circuit loop is formed due to insulation failure of a thermal runaway battery cell and peripheral battery cells, ignition, thermal runaway diffusion, short circuit melting-through of a PACK box body and the like are caused, and finally the PACK is on fire or exploded are solved.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage, and particularly to a battery pack and an energy storage device. Background Art

[0002] The battery pack in the related art includes a housing and a plurality of battery cells located inside the housing. The plurality of battery cells are connected in series or in parallel through aluminum bars. However, when some battery cells are thermally out of control, the battery cells may eject electrolyte or some metal impurities from their pressure relief valves. When these metal impurities fall, they may overlap on different aluminum bars, resulting in a short circuit between different aluminum bars due to the metal impurities. Moreover, when the battery cells are thermally out of control, the battery cells will expand and deform, and the aluminum bars provided on the battery cells will move along with the expansion of the battery cells, resulting in the possibility that the plurality of aluminum bars may come into contact with the top wall of the housing, which may cause a short circuit between the plurality of aluminum bars due to the top wall of the housing. The short circuit between the busbars will cause electrical arcing, which will further deteriorate the thermal out of control, and even more seriously, it may cause the explosion of the battery pack, bringing great safety risks. Summary of the Utility Model

[0003] The embodiments of the present application provide a battery pack and an energy storage device to reduce the risk of short circuit between a plurality of busbars connecting a plurality of battery cells, effectively avoid the further deterioration of the thermal out of control of the battery pack, and improve safety.

[0004] In a first aspect, an embodiment of the present application provides a battery pack, which includes a housing, a battery module, a plurality of busbars, and an insulating first isolation strip received in the housing; the battery module includes a plurality of battery cells arranged along the length direction of the battery pack, the plurality of busbars are provided on the surfaces where the pole columns of the plurality of battery cells are located, two adjacent battery cells among the plurality of battery cells are electrically connected through one of the plurality of busbars, and the plurality of busbars are arranged in the length direction of the battery pack; the first isolation strip extends along the length direction of the battery pack and covers the surfaces of the plurality of busbars facing away from the plurality of battery cells; there is a gap between the first isolation strip and the pressure relief valves of the plurality of battery cells in the direction of the interval between the pole column and the pressure relief valve.

[0005] In this embodiment, since the surfaces of multiple busbars facing the top wall of the housing are covered by the first isolation strip, and the first isolation strip is arranged between the multiple busbars and the top wall of the housing, when one or some of the battery cells in the battery pack undergo thermal runaway, the battery cells expand and drive the busbars to move towards the top wall of the housing. However, due to the first isolation strip being located between the multiple busbars and the top wall of the housing, under the isolation of the first isolation strip, the busbars will not directly contact the top wall of the housing, thus avoiding short-circuiting between the multiple busbars through the top wall of the housing, effectively reducing the probability of the battery pack exploding and the probability of further deterioration of the thermal runaway of the battery pack. Moreover, when metal impurities are ejected during the thermal runaway of the battery cells, since the surfaces of the multiple busbars facing the top wall of the housing are covered by the first isolation strip, when the ejected metal impurities fall, they will land on the first isolation strip and will not directly contact the multiple busbars. Thus, through the isolation of the first isolation strip, the risk of short-circuiting of the multiple busbars by metal impurities can be effectively reduced, and further, the risk of further deterioration of the thermal runaway of the battery pack can be effectively reduced.

[0006] Based on the second embodiment of the first aspect described above, two rows of busbars are provided on the surface where the pole columns of multiple battery cells are located. In the direction of the interval between the pole column and the pressure relief valve, the two rows of busbars are located on both sides of the pressure relief valves of multiple battery cells. Each row of busbars in the two rows of busbars includes multiple busbars arranged at intervals along the length direction of the battery pack; two first isolation strips respectively cover the two rows of busbars; in the direction of the interval between the pole column and the pressure relief valve, the two first isolation strips are respectively located on both sides of the pressure relief valves of multiple battery cells. In this embodiment, since the arrangement directions of multiple battery cells are the same, the pressure relief valves of multiple battery cells in each battery module are arranged in a row at intervals in the length direction of the battery pack. And the busbars are usually conductive and are usually rigid aluminum bars or copper bars. Since the two rows of busbar groups are respectively located on both sides of the pressure relief valve, that is, the busbars are arranged to avoid the pressure relief valve, that is, the pressure relief valve cannot be aligned with the busbars, to prevent the pressure relief valve from not being able to open in time and to avoid the substances ejected from the pressure relief valve from short-circuiting the multiple busbars. Moreover, in the direction of the interval between the pole column and the pressure relief valve (that is, the width direction of the battery pack), the two first isolation strips are respectively located on both sides of the pressure relief valves of multiple battery cells. Thus, the pressure relief valves of multiple battery cells in each battery module are reasonably avoided from the busbars and the first isolation strip, effectively preventing the pressure relief valve of the battery cell from not being effectively opened, and also reducing the risk of contact between the impurities ejected from the pressure relief valve and the busbars and the risk of short-circuiting between the multiple busbars by impurities. Moreover, since no first isolation strip is provided at the position of the pressure relief valves of multiple battery cells, the usage area of the first isolation strip can be reduced, and the usage cost of the first isolation strip can be reduced.

[0007] The third embodiment based on any of the above embodiments. Each busbar among the multiple busbars has a long strip structure extending along the length direction of the battery pack, and each busbar is entirely covered by the first isolation strip; in the length direction of the battery pack, the length of the first isolation strip is greater than or equal to the length after the multiple battery cells are arranged; in the interval direction between the terminal post and the pressure relief valve, the width of the first isolation strip is greater than or equal to the width of the busbar. In this embodiment, the surface of each busbar facing away from the multiple battery cells is entirely covered by the first isolation strip, so that the protection and isolation ability of the first isolation strip for the busbar can be effectively improved, and the risk of short circuit between the multiple busbars can be effectively reduced.

[0008] The fourth embodiment based on any of the above embodiments. The first isolation strip includes two integrally formed parts. One part covers the busbar, and the other part extends from the busbar to the side wall of the multiple battery cells and covers part or all of the side wall. The side wall of the multiple battery cells is the surface adjacent to the surface where the terminal post is located. In this embodiment, since one part covers the upper surface of the busbar group, and the other part extends from the busbar to the side wall of the multiple battery cells and covers part or all of the side wall, the side surface of the busbar group facing away from the pressure relief valve can be covered. Thus, the adjacent two busbar groups on the adjacent two battery modules are covered by the other part of the first isolation strip. Therefore, even if the battery cells expand and drive the busbar to move, due to the isolation of the other part of the first isolation strip, short circuit between the adjacent two busbar groups on the adjacent two battery modules will not occur.

[0009] The fifth embodiment based on any of the above embodiments. The first isolation strip is a flexible structure, and the surface of the multiple busbars facing away from the multiple battery cells is in contact with the first isolation strip. In this embodiment, since the first isolation strip is flexible, most areas of the surface of the busbar facing the top wall of the housing can be effectively attached by the first isolation strip, so that the gap between the busbar and the first isolation strip can be effectively reduced. Furthermore, it can basically prevent metal impurities from entering between the first isolation strip and the busbar and contacting the busbar, and thus the risk of short circuit between the multiple busbars due to impurities ejected from the battery cells can be effectively reduced.

[0010] The sixth embodiment based on any of the above embodiments. The first isolation strip has insulating properties in both the normal state and the thermal runaway state of the battery cells. Thus, the first isolation strip in this embodiment can maintain its insulating effect when the battery cells in the battery pack are in thermal runaway. Furthermore, when the battery cells are in thermal runaway, the first isolation strip in this embodiment can still play a role in protecting the busbars, and can still prevent the multiple busbars from being short-circuited by metal impurities or metal housing ejected from the battery cells. Therefore, the risk of further deterioration of the battery pack in the case of internal battery cell thermal runaway can be reduced, as well as the risk of explosion of the battery pack, thereby effectively improving the safety performance of the battery pack in the case of thermal runaway.

[0011] According to the seventh embodiment based on any of the above embodiments, the first isolation strip has insulating properties within the temperature range less than 1000°C.

[0012] According to the eighth embodiment based on any of the above embodiments, fixing holes are provided on multiple busbars, and the fixing holes are used to fix the first isolation strip. In this embodiment, since fixing holes are provided on multiple busbars, relative fixation between the multiple busbars and the first isolation strip can be achieved through the fixing holes, so as to avoid changes in the relative positions between the first isolation strip and the busbars when the battery cell expands. In addition, since the first isolation strip and the multiple busbars are fixed together, that is, the first isolation strip can be pressed against the busbars, thereby reducing the gap between the surface of the first isolation strip and the multiple busbars facing the housing, and effectively reducing the probability of metal impurities ejected from the battery cell entering the gap between the first isolation strip and the multiple busbars.

[0013] According to the ninth embodiment based on any of the above embodiments, the busbar includes multiple bottom plates electrically connected to the pole columns of multiple battery cells and an arched plate integrally formed between two adjacent bottom plates among the multiple bottom plates. In the height direction of the battery pack, the arched plate is higher than the bottom plates, and fixing holes are provided on each bottom plate, and the fixing holes are used to fix with the first isolation strip. In this embodiment, since the fixing holes are provided on the lower-positioned bottom plates, when the busbar and the first isolation strip are fixed together through the fixing holes, the gap between the first isolation strip and the bottom plates can be effectively reduced, enabling the first isolation strip to better fit the uneven busbars, thereby providing a better protection effect on the busbars.

[0014] According to the tenth embodiment based on any of the above embodiments, the battery pack further includes a bracket, the bracket is provided on one side of the top wall of the battery module facing the housing, the bracket includes multiple rows of strip-shaped groove groups arranged at intervals in the width direction of the battery pack, each row of strip-shaped groove groups includes multiple strip-shaped grooves arranged at intervals in the length direction of the battery pack, one busbar is installed in each strip-shaped groove, through holes are provided on the bottom surfaces of the multiple strip-shaped grooves, and the positive pole column or negative pole column of the battery cell is located in the through hole and contacts the busbar. In this embodiment, the busbar is connected to the positive pole column or negative pole column of the battery cell through the through hole, and the busbar installed in the strip-shaped groove can effectively limit the position of the busbar, thereby ensuring the stability of the busbar and ensuring the stability of the connection between the busbar and the positive pole column or negative pole column of the battery cell.

[0015] According to the eleventh embodiment based on any of the above embodiments, the first isolation strip covers the busbar group and is fixed to the bracket. In this embodiment, by fixing the first isolation strip to the bracket, and the busbar is arranged in the strip-shaped groove of the bracket, the relative position between the first isolation strip and the busbar can be kept fixed, so that the first isolation strip stably covers the busbar.

[0016] The twelfth embodiment based on any of the above embodiments, the bracket further includes a plurality of fixing platforms, the plurality of fixing platforms are arranged at intervals in the strip-shaped groove along the length direction of the battery pack, and fixing holes are provided on the plurality of fixing platforms for fixing with the first isolation belt. In this embodiment, by fixing the first isolation belt through the fixing holes on the plurality of fixing platforms, the fixing stability of the first isolation belt can also be improved.

[0017] The thirteenth embodiment based on any of the above embodiments, the number of brackets is multiple, the number of battery modules is multiple. In the height direction of the battery pack, one bracket is provided on one side of each battery module facing the top wall of the housing. In the width direction of the battery pack, the plurality of brackets are arranged at intervals. The first isolation belt is a flexible structure, and a part of the first isolation belt is located between two adjacent brackets. In this embodiment, since a part of the first isolation belt is located between two adjacent brackets, in a high-temperature environment, even if the bracket melts, there is still a part of the first isolation belt between the adjacent busbar groups on the adjacent two battery modules, so that short circuit between the adjacent busbar groups on the adjacent two battery modules can be effectively avoided.

[0018] The fourteenth embodiment based on any of the above embodiments, the battery pack further includes a plurality of flexible and insulating second isolation belts; the number of battery modules is multiple, the plurality of battery modules are arranged along the width direction of the battery pack, and a second isolation belt is provided between two adjacent battery modules, and the second isolation belt is located between the opposite side walls of the two adjacent battery modules. In this embodiment, since the second isolation belt is high-temperature resistant, when one or some of the battery cells are out of control thermally, the generated high temperature still cannot affect the performance of the second isolation belt. Therefore, in a high-temperature environment, the insulation between the battery cells of the two adjacent battery modules can still be ensured to prevent short circuit between the battery cells of the two adjacent battery modules.

[0019] The fifteenth embodiment based on any of the above embodiments is that each of the multiple battery modules further includes end plates disposed at both ends in the arrangement direction of the multiple battery cells and cable ties for bundling the multiple battery cells and the end plates; in the width direction of the battery pack, second isolation belts are disposed on both sides of the battery module, and the cable ties bundle the second isolation belts on two sides of the multiple battery cells in the width direction of the battery pack. In this embodiment, when assembling the battery module, the second isolation belt is bundled on two sides of the battery module in the width direction of the battery pack by the cable ties, which not only realizes the reasonable fixation of the second isolation belt, but also eliminates the need for other fixing methods to fix the second isolation belt when installing multiple subsequent battery modules, reducing the installation difficulty between multiple subsequent battery modules. In addition, since the cable ties are usually metal cable ties and the insulating coatings on the cable ties are usually not resistant to high temperatures, the second isolation belt is disposed between the multiple battery cells and the cable ties, so that in a high-temperature environment, even if the insulating coatings on the cable ties melt and fail, the second isolation belt can effectively prevent short circuits between multiple battery cells through the cable ties.

[0020] The sixteenth embodiment based on any of the above embodiments is that in the height direction of the battery pack, the second isolation belt extends to contact the first isolation belt. In this embodiment, since the second isolation belt extends to contact the first isolation belt, a part of the second isolation belt extends between adjacent busbar groups of adjacent battery modules, thereby avoiding the problem of short circuits between adjacent busbar groups on adjacent battery modules.

[0021] In a second aspect, an embodiment of the present application provides an energy storage device, which includes a cabinet and one or more battery packs according to any one of the above embodiments, and the one or more battery packs are disposed in the cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art.

[0023] Figure 1 It is a schematic structural diagram of a battery pack provided by an embodiment of the present application;

[0024] Figure 2 For Figure 1 the exploded structural diagram of the battery pack in

[0025] Figure 3 For Figure 1 the exploded structural diagram of the partial structure of the battery pack in the embodiment after removing the housing;

[0026] Figure 4 For Figure 1 the partial structural diagram of the battery pack in the embodiment;

[0027] Figure 5 is Figure 1 a partial view of the front view of a partial structure of the battery pack in the embodiment;

[0028] Figure 6 is Figure 1 a partial view of the left view of a partial structure of the battery pack in the embodiment;

[0029] Figure 7 is Figure 4 a partial enlarged schematic view at position A in;

[0030] Figure 8 is Figure 3 a schematic structural view of the bracket in the embodiment;

[0031] Figure 9 is Figure 1 a schematic exploded view of the battery module in the battery pack in the embodiment.

[0032] Explanation of reference numerals:

[0033] X, the length direction of the battery pack; Y, the width direction of the battery pack; Z, the height direction of the battery pack;

[0034] 4, battery pack; 7, housing; 7a, upper cover; 7b, lower box body; 71, top wall of the housing;

[0035] 10, battery module; 11, battery cell; 101, terminal; 111, positive terminal; 112, negative terminal; 113, pressure relief valve; 114, side wall of the battery cell; 115, surface where the terminal of the battery cell is located; 12, end plate; 13, cable tie;

[0036] 21, bus bar; 201, fixing hole; 211, surface of the bus bar facing away from multiple battery cells; 212, surface of the bus bar facing away from the pressure relief valve; 213, bottom plate; 214, arched plate;

[0037] 31, first isolation strip; 311, one part; 312, another part; 32, second isolation strip; 33, third isolation strip;

[0038] 40, bracket; 41, strip-shaped groove group; 411, strip-shaped groove; 412, through hole; 42, limiting groove; 43, fixing table; 431, fixing hole;

[0039] 50, flexible circuit board. Detailed implementation manners

[0040] First, some terms related to the embodiments of the present application are explained as follows.

[0041] In the description, claims, and above-mentioned drawings of the embodiments of the present application, terms such as "first", "second", "third", "fourth", etc. are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described herein, for example, can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that comprises a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0042] Explanation of terms such as "vertical" and "parallel" in this specification.

[0043] Vertical: The vertical defined in the present application is not limited to an absolute vertical intersection (angle of 90 degrees). A relationship that is not an absolute vertical intersection due to factors such as assembly tolerances, design tolerances, and the influence of structural flatness is allowed. An error within a small angle range is allowed. For example, within an assembly error range of 80 degrees to 100 degrees, it can be understood as a vertical relationship.

[0044] Parallel: The parallel defined in the present application is not limited to absolute parallelism. This definition of parallel can be understood as substantially parallel. A situation that is not absolutely parallel due to factors such as assembly tolerances, design tolerances, and the influence of structural flatness is allowed. These situations may result in the sliding fit portion and the first door panel not being absolutely parallel, but the present application also defines such a situation as parallel.

[0045] To facilitate the understanding of the energy storage device provided by the embodiments of the present application, the following first introduces its application scenarios. The energy storage device is a system that can store electrical energy through a certain medium and release the stored energy for power generation when needed. It can be used as a load balancing device and a backup power supply in industrial and commercial parks, household living environments, large-scale ground power supply stations, or photovoltaic energy storage systems and other scenarios. Taking the photovoltaic energy storage system scenario as an example, the application of the energy storage device will be briefly described. A photovoltaic energy storage system usually includes photovoltaic modules, an energy storage inverter, an energy storage device, and a grid-connected inverter. Among them, the photovoltaic modules can convert light energy into electrical energy in the form of direct current and output it to the grid-connected inverter; the grid-connected inverter can convert the electrical energy in the form of direct current into electrical energy in the form of alternating current and transmit the alternating current electrical energy to the grid, thereby realizing the grid connection of the photovoltaic energy storage system. The energy storage device can store a part of the electrical energy output by the photovoltaic inverter when the electrical energy generated by the photovoltaic modules exceeds the demand for electrical energy by the grid, and output the stored electrical energy to the grid when the electrical energy output by the photovoltaic modules cannot meet the demand for electrical energy by the grid, so as to provide a more stable DC source for the grid. The energy storage inverter can convert the grid voltage into the power supply voltage of the energy storage device, or convert the voltage stored in the energy storage device into the grid voltage and output it to the grid.

[0046] In addition, according to the different requirements of the application scenarios of the energy storage device for the electricity consumption, the energy storage device can also be divided into cabinet-level energy storage devices and container-level energy storage devices.

[0047] In some embodiments, the energy storage device includes a cabinet body and a battery cluster provided in the cabinet body.

[0048] The battery cluster includes a plurality of battery packs stacked on top of each other.

[0049] The energy storage device may further include a cluster control box and a power converter, and the cluster control box and the power converter are provided in the cabinet body.

[0050] In some embodiments, the power converter includes a PCS (power conversion system) converter, and the cluster control box is connected between the PCS converter and the battery cluster. With such a design, the direct current of the battery cluster can be converted into alternating current by the PCS converter to supply power to an external load. In addition, when the current between the battery cluster and the PCS converter is too large, the cluster control box can timely disconnect the PCS converter from the battery cluster to prevent accidents such as fires of the battery cluster or external loads.

[0051] In some embodiments, when the voltage output by the battery cluster is lower than the rated voltage, in order to ensure the stability of the output voltage of the energy storage device, the power converter further includes a DC / DC (direct current / direct current) converter. The DC / DC converter is connected between the PCS converter and the cluster control box, and the cluster control box is connected between the DC / DC converter and the battery cluster. The DC / DC converter boosts or buckles the voltage output by the battery cluster, so as to ensure that the voltage delivered to the PCS converter remains stable, thereby ensuring the stability of the output voltage of the energy storage device. Moreover, when the current between the battery cluster and the PCS converter is too large, the cluster control box can timely disconnect the current between the PCS converter and the battery cluster to prevent accidents such as fires in the battery cluster or external loads.

[0052] Figure 1 Schematic diagram of the structure of a battery pack 4 provided by an embodiment of the present application; Figure 2 is Figure 1 exploded view of the battery pack 4 in Figure 3 is Figure 1 exploded view of a partial structure of the battery pack 4 excluding the housing 7 in the embodiment; Figure 4 is Figure 1 partial structure diagram of the battery pack 4 in the embodiment.

[0053] Referring to Figure 1 and Figure 2 the battery pack 4 includes a housing 7 and a battery module 10 housed in the housing 7.

[0054] The housing 7 includes an upper cover 7a and a lower box body 7b. The upper cover 7a is fixed on the lower box body 7b and encloses a receiving cavity with the lower box body 7b. The battery module 10 is housed in the receiving cavity. Specifically, the battery module 10 is first installed on the lower box body 7b, and then fixed on the lower box body 7b by the upper cover 7a, thereby realizing the encapsulation of the battery module 10.

[0055] Referring to Figure 3 and Figure 4 the number of the battery modules 10 can be multiple, and each battery module 10 includes a plurality of battery cells 11 arranged along the length direction X of the battery pack 4. The plurality of battery modules 10 are arranged in the width direction Y of the battery pack 4.

[0056] Of course, in some other embodiments, the number of the battery modules 10 can also be one.

[0057] Referring to Figures 2 - 4, in order to connect multiple battery cells 11 in series or in parallel, the battery pack 4 further includes a plurality of busbars 21 for connecting the multiple battery cells 11 in the multiple battery modules 10 in series or in parallel. The plurality of busbars 21 are provided on the surface 115 where the electrode posts 101 of the multiple battery cells 11 in the battery module 10 are located, that is, the plurality of busbars 21 are provided on the side of the multiple battery modules 10 facing the housing 7, that is, the plurality of busbars 21 are located between the multiple battery modules 10 and the housing 7. It can be understood that the series and parallel connections between the multiple battery cells 11 in each battery module 10 usually require a plurality of busbars 21 for connection, and the series or parallel connection between the battery modules 10 is also connected through the busbars 21. For example, two or more adjacent battery cells 11 among the multiple battery cells 11 are electrically connected through one of the plurality of busbars 21, that is, one busbar 21 can electrically connect two or more adjacent battery cells 11 to make the multiple battery cells 11 connected in series or in parallel.

[0058] Referring to Figure 2 and Figure 4 , for example, in a specific embodiment, the positive electrode posts 111, negative electrode posts 112, etc. of the multiple battery cells 11 in the multiple battery modules 10 are all arranged facing the top wall 71 of the housing 7 to facilitate the connection of the busbars 21. In order to improve the connection stability between the busbars 21 and the positive electrode posts 111 and negative electrode posts 112 of the battery cells 11, hard aluminum bars or copper bars, etc. are usually used to connect the positive electrode posts 111 and negative electrode posts 112 of the battery cells 11.

[0059] However, when a thermal runaway occurs in the battery cell 11, the battery cell 11 will expand, and the expanded battery cell 11 drives the busbar 21 to move towards the top wall 71 of the housing 7, so there is a risk that the busbar 21 contacts the top wall 71 of the housing 7, and further there is a risk of short circuit between the multiple busbars 21 through the top wall 71 of the housing 7. And a short circuit between the multiple busbars 21 may cause the battery pack 4 to explode due to electrical arcing, resulting in further expansion of the thermal runaway range of the battery cells 11 and further deterioration of the thermal runaway of the battery pack 4. In addition, since the electrolyte and some metal impurities, such as debris of the electrode plate and electrode tab, etc., will be directly ejected through the pressure relief valve 113 of the battery cell 11 during thermal runaway, these ejected impurities may lap on multiple different busbars 21 when falling, thus causing a short circuit between the multiple busbars 21 through the metal impurities, and further deteriorating the thermal runaway situation of the battery pack 4.

[0060] Figure 5 For Figure 1 a partial front view of a part of the structure of the battery pack 4 in the embodiment; Figure 6 For Figure 1 a partial left view of a part of the structure of the battery pack 4 in the embodiment.

[0061] Referring to Figures 2 - 6, to solve the problem that when thermal runaway occurs, multiple busbars 21 are short-circuited through the top wall 71 of the housing 7 or impurities, the battery pack 4 of the embodiment of the present application further includes an insulating first isolation strip 31, which covers multiple busbars 21 through the first isolation strip 31, for example, covers the surface 211 of multiple busbars 21 facing away from multiple battery cells 11, and the first isolation strip 31 is located between multiple busbars 21 and the housing 7. That is, multiple busbars 21 and the housing 7 are isolated by the first isolation strip 31. That is, in the height direction Z of the battery pack 4, a first isolation strip 31 is provided between multiple busbars 21 and the housing 7. Since the surface 211 of multiple busbars 21 facing away from multiple battery cells 11 is covered by the first isolation strip 31, and the first isolation strip 31 is arranged between multiple busbars 21 and the housing 7, when a certain or some battery cells 11 in the battery pack 4 undergo thermal runaway, the battery cells 11 expand and drive the busbars 21 to move towards the housing 7. However, due to the first isolation strip 31 being located between multiple busbars 21 and the housing 7, under the isolation of the first isolation strip 31, the busbars 21 will not directly contact the housing 7, thus avoiding short-circuiting between multiple busbars 21 through the housing 7, effectively reducing the probability of explosion of the battery pack 4 and reducing the probability of further deterioration of thermal runaway of the battery pack 4. Moreover, when metal impurities are ejected during thermal runaway of the battery cells 11, since the surface 211 of multiple busbars 21 facing away from multiple battery cells 11 is covered by the first isolation strip 31, when the ejected metal impurities fall, they will fall on the first isolation strip 31 and will not directly contact multiple busbars 21. Thus, through the isolation of the first isolation strip 31, the risk of short-circuiting of multiple busbars 21 by metal impurities can be effectively reduced, and further the risk of further deterioration of thermal runaway of the battery pack 4 can be effectively reduced.

[0062] In addition, there is a gap between the first isolation strip 31 and the pressure relief valves 113 of the multiple battery cells 11 in the direction of the interval between the pole posts 101 and the pressure relief valves 113. That is, in the height direction Z of the battery pack 4, the first isolation strip 31 does not cover the pressure relief valves 113 of the battery cells 11. That is to say, in the height direction Z of the battery pack 4, the first isolation strip 31 is not directly opposite to the pressure relief valves 113 of the battery cells 11. It can be understood that the direction of the interval between the pole posts 101 and the pressure relief valves 113 is also the direction in which the pole posts 101 and the pressure relief valves 113 are arranged. In this embodiment, since there is a gap between the first isolation strip 31 and the pressure relief valves 113 of the multiple battery cells 11 in the direction of the interval between the pole posts 101 and the pressure relief valves 113, the pressure relief valves 113 are not covered by the first isolation strip 31. Therefore, when the battery cell 11 is in thermal runaway, the normal opening of the pressure relief valve 113 of the battery cell 11 will not be affected by the first isolation strip 31. Thus, the setting of the first isolation strip 31 will not affect the normal pressure relief of the battery cell 11, and the risk of explosion of the battery cell 11 can be reduced. In this embodiment, by covering the first isolation strip 31 on the surface 211 of the multiple busbars 21 facing away from the multiple battery cells 11, and there is a gap between the first isolation strip 31 and the pressure relief valves 113 of the multiple battery cells 11 in the direction of the interval between the pole posts 101 and the pressure relief valves 113, the risk of short circuit of the multiple busbars 21 can be effectively reduced without affecting the normal opening of the pressure relief valves 113 of the battery cells 11, thereby effectively improving the safety performance of the battery pack 4.

[0063] Referring to Figures 2 - 4 , in some embodiments, the multiple busbars 21 are arranged in the length direction X of the battery pack 4, and the first isolation strip 31 extends along the length direction X of the battery pack 4. That is, the first isolation strip 31 has a long strip-like structure, so that each first isolation strip 31 can cover the multiple busbars 21. Such a setting not only facilitates the layout of the first isolation strip 31 covering the multiple busbars 21, but also helps the first isolation strip 31 to avoid the pressure relief valves 113 of the multiple battery cells 11, making the overall layout of the first isolation strip 31 more concise and reasonable.

[0064] Referring to Figures 2 - 6 , in some embodiments, the first isolation strip 31 is a flexible structure, and the surface 211 of the multiple busbars 21 facing away from the multiple battery cells 11 is in contact with the first isolation strip 31. The first isolation strip 31 is attached to or substantially attached to the surface 211 of the multiple busbars 21 facing away from the multiple battery cells 11. That is, the gap between the first isolation strip 31 and the surface 211 of the multiple busbars 21 facing away from the multiple battery cells 11 is small enough so that the metal impurities ejected from the battery cell 11 can basically not enter the gap between the first isolation strip 31 and the multiple busbars 21.

[0065] In order to better protect the multiple busbars 21 through the first isolation tape 31, in some embodiments, because in the height direction Z of the battery pack 4, the surfaces 211 of the multiple busbars 21 away from the multiple battery cells 11 have high parts and low parts, that is, the surfaces of the busbars 21 away from the multiple battery cells 11 are uneven. That is, at least part of the surfaces 211 of the multiple busbars 21 away from the multiple battery cells 11 is a curved surface. Since the first isolation tape 31 is a flexible structure, the first isolation tape 31 can basically fit on most areas of the surfaces 211 of the multiple busbars 21 away from the multiple battery cells 11. As a result, most of the surface 211 of the bus 21 that faces away from the multiple battery cells 11 can be effectively adhered to the first isolation zone 31, thereby effectively reducing the gap between the bus 21 and the first isolation zone 31, and basically preventing metal impurities from entering between the first isolation zone 31 and the bus 21 and contacting the bus 21, thereby effectively reducing the risk of short circuit between multiple bus bars 21 due to impurities ejected from the battery cells 11.

[0066] In some embodiments, the first isolation zone 31 has insulation performance in both the normal state and the thermal runaway state of the battery cell 11. For example, in some embodiments, the first isolation zone 31 has insulation performance in a temperature range of less than 1000°C.

[0067] For another example, the first isolation tape 31 has a higher heat resistance than a high temperature thermosetting board, for example, the first isolation tape 31 has a higher heat resistance than a FR-4 (epoxy) board, etc. For example, in some embodiments, the first isolation tape 31 is a ceramic composite tape.

[0068] In the embodiment of the present application, since the first isolation zone 31 is in a high temperature environment within the range of 1000°C, the first isolation zone 31 will not lose its insulating effect. The temperature of the battery cell 11 in the battery pack 4 during thermal runaway is usually less than 1000°C, so the first isolation zone 31 in this embodiment can maintain its insulating effect when the battery cell 11 in the battery pack 4 is in thermal runaway. Furthermore, when the battery cell 11 is in thermal runaway, the first isolation zone 31 in this embodiment can still protect the bus 21, and can still prevent multiple bus bars 21 from being short-circuited by metal impurities or metal shells 7 ejected from the battery cell 11, thereby reducing the risk of further deterioration of the battery pack 4 in the case of thermal runaway of the internal battery cell 11, and reducing the risk of explosion of the battery pack 4, thereby effectively improving the safety performance of the battery pack 4 in the case of thermal runaway.

[0069] It is understandable that the arrangement of the first isolation zone 31 and the multiple bus bars 21 can be varied. For example, in some embodiments, multiple first isolation zones 31 can be selectively provided above the multiple bus bars 21 so that the shell 7 and the multiple bus bars 21 can be isolated by the multiple first isolation zones 31.

[0070] Referring to Figures 4 - 6 , in order to effectively reduce the risk of short - circuit between multiple busbars 21 through the first isolation strip 31, it is also important to reasonably arrange multiple battery cells 11, multiple busbars 21, the first isolation strip 31, etc.

[0071] For the multiple battery cells 11 of each battery module 10, the arrangement directions of the multiple battery cells 11 are the same, that is, the long - side orientations, wide - side directions, and height directions of the multiple battery cells 11 are all the same, so that the multiple battery cells 11 can be arranged neatly. Specifically, the long - side orientation of the multiple battery cells 11 is consistent with the width direction Y of the battery pack 4, and the arrangement direction of the multiple battery cells 11 is also the width direction of the multiple battery cells 11, and the arrangement direction of the multiple battery cells 11 is also consistent with the length direction X of the battery pack 4. The pressure - relief valve 113 is usually arranged on one side of the battery cell 11 facing the top wall 71 of the housing 7. Thus, along the long - side direction of the battery cell 11, the pressure - relief valves 113 of the multiple battery cells 11 are located between the positive electrode post 111 and the negative electrode post 112 and are spaced from the positive electrode post 111 and the negative electrode post 112. Since the arrangement directions of the multiple battery cells 11 are the same, the pressure - relief valves 113 of the multiple battery cells 11 of each battery module 10 are arranged in a row at intervals in the length direction X of the battery pack 4. The busbar 21 is usually conductive and is usually a rigid aluminum bar or copper bar. Therefore, the busbar 21 is arranged to avoid the pressure - relief valve 113, that is, the pressure - relief valve 113 cannot be aligned with the busbar 21, so as to prevent the pressure - relief valve 113 from not being able to open in time and to avoid the substances ejected by the pressure - relief valve 113 from short - circuiting the multiple busbars 21.

[0072] Referring to Figures 2 - 6, in order to avoid arranging the bus bar 21 and the pressure relief valve 113, in some embodiments, in the width direction Y of the battery pack 4, on both sides of the pressure relief valve 113 of the multiple battery cells 11 of each battery module 10, a row of bus bars 21 is provided, and each row of bus bars 21 includes multiple bus bars 21 spaced along the length direction X of the battery pack 4. That is, for the two rows of bus bars 21 on the multiple battery cells 11 of each battery module 10, since the two rows of bus bars 21 are respectively located on both sides of the pressure relief valve 113, the two first isolation bands 31 respectively cover the two rows of bus bars 21; in the interval direction between the pole 101 and the pressure relief valve 113 (i.e., the width direction Y of the battery pack 4), the two first isolation bands 31 are respectively located on both sides of the pressure relief valve 113 of the multiple battery cells 11. Thus, the pressure relief valve 113 of the multiple battery cells 11 of each battery module 10 is reasonably avoided from the bus bar 21 and the first isolation band 31, so as to effectively prevent the pressure relief valve 113 of the battery cell 11 from not being effectively opened, and also reduce the risk of the impurities ejected from the pressure relief valve 113 contacting the bus bar 21 and the risk of short circuit between the multiple bus bars 21 caused by impurities. Moreover, since the first isolation band 31 is not provided at the position of the pressure relief valve 113 of the multiple battery cells 11, the usage area of the first isolation band 31 can also be reduced, and the usage cost of the first isolation band 31 can be reduced.

[0073] Figure 7 For Figure 4 The partial enlarged schematic diagram at position A in the figure.

[0074] Refer to Figure 4 And Figure 7 Refer to

[0075] Refer to Figure 4 And Figure 7 , for example, in some embodiments, in the length direction X of the battery pack 4, the length of the first isolation band 31 is greater than or equal to the length after the multiple battery cells 11 are arranged, and the multiple bus bars 21 are arranged on the surface 115 where the pole 101 of the multiple battery cells 11 is located. Thus, the first isolation band 31 can completely cover the multiple bus bars 21 in the arrangement direction of the multiple battery cells 11 (the length direction X of the battery pack 4). In the interval direction between the pole 101 and the pressure relief valve 113, the width of the first isolation band 31 is greater than or equal to the width of the bus bar 21. Thus, the first isolation band 31 can completely cover the multiple bus bars 21 in the interval direction between the pole 101 and the pressure relief valve 113.

[0076] Reference Figure 4 and Figure 7 When the battery cell 11 undergoes thermal runaway, it will expand. If relative displacement occurs between the bus bar 21 on the battery cell 11 and the first isolation strip 31 on the bus bar 21, the part of the bus bar 21 that deviates from the surface 211 of the multiple battery cells 11 will no longer be covered by the first isolation strip 31, and there is a risk of short - circuiting for the part of the bus bar 21 not covered by the first isolation strip 31. To solve this problem and avoid increasing the assembly difficulty, in some embodiments, fixing holes 201 are provided on multiple bus bars 21 to relatively fix the multiple bus bars 21 and the first isolation strip 31 through the fixing holes 201, so as to prevent the relative position between the first isolation strip 31 and the bus bar 21 from changing when the battery cell 11 expands. In addition, since the first isolation strip 31 and the multiple bus bars 21 are fixed together, that is, the first isolation strip 31 can be pressed tightly against the bus bar 21, thereby reducing the gap between the surface of the first isolation strip 31 and the multiple bus bars 21 facing the housing 7, and effectively reducing the probability of metal impurities ejected from the battery cell 11 entering the gap between the first isolation strip 31 and the multiple bus bars 21. It can be understood that multiple fixing holes 201 can be provided on multiple bus bars 21. Specifically, the first isolation strip 31 and the multiple bus bars 21 can be fixed by means of screws or rivets cooperating with the fixing holes 201.

[0077] Reference Figure 4 and Figure 7 In some embodiments, the bus bar 21 includes multiple bottom plates 213 electrically connected to the pole columns 101 of the multiple battery cells 11 and an arched plate 214 integrally formed between two adjacent bottom plates 213 among the multiple bottom plates 213. In the height direction Z of the battery pack 4, the arched plate 214 is higher than the bottom plate 213, and fixing holes 201 are provided on the bottom plates 213, and the fixing holes 201 are used to fix with the first isolation strip 31. In this embodiment, since the fixing holes 201 are provided on the lower - positioned bottom plates 213, when the bus bar 21 and the first isolation strip 31 are fixed together through the fixing holes 201, the gap between the first isolation strip 31 and the bottom plate 213 can be effectively reduced, enabling the first isolation strip 31 to better fit the uneven bus bar 21, thereby providing a better protection effect on the bus bar 21.

[0078] Figure 8 For Figure 3 a schematic structural view of the bracket 40 in the embodiment.

[0079] Reference Figures 3 - 8, in order to stably connect multiple busbars 21 to the positive electrode post 111 or negative electrode post 112 of the battery cell 11, that is, to ensure the connection stability between the battery cell 11 and the busbar 21. In some embodiments, the battery pack 4 further includes a bracket 40, and the bracket 40 is provided on the surface 115 where the electrode posts 101 of the multiple battery cells 11 of the multiple battery modules 10 are located. It can be understood that the number of brackets 40 can be one, for example, covering multiple battery modules 10 with a large bracket 40, or the number of brackets 40 can also be multiple, and multiple brackets 40 cover the corresponding multiple battery modules 10. For example, one bracket 40 can cover one battery module 10, or one bracket 40 can cover two adjacent battery modules 10, etc.

[0080] The bracket 40 is provided with multiple columns of strip-shaped groove groups 41 for installing the busbars 21. The multiple columns of strip-shaped groove groups 41 are arranged at intervals along the width direction Y of the battery pack 4. Each column of strip-shaped groove groups 41 includes multiple strip-shaped grooves 411 arranged at intervals along the length direction X of the battery pack 4. The bottom wall of each strip-shaped groove 411 is penetrated at a position corresponding to the positive electrode post 111 or negative electrode post 112 of the battery cell 11. That is, a through hole 412 is provided at a position on the bottom wall of the strip-shaped groove 411 where it faces the positive electrode post 111 or negative electrode post 112 of the battery cell 11 in the height direction Z of the battery pack 4. One busbar 21 can be installed in each strip-shaped groove 411. The busbar 21 is connected to the positive electrode post 111 or negative electrode post 112 of the battery cell 11 through the through hole 412. Installing the busbar 21 in the strip-shaped groove 411 can effectively limit the position of the busbar 21, thereby ensuring the stability of the busbar 21 and ensuring the connection stability between the busbar 21 and the positive electrode post 111 or negative electrode post 112 of the battery cell 11.

[0081] It can be understood that the bracket 40 is made of an insulating material, such as a plastic material. After the multiple busbars 21 are correspondingly installed in the multiple strip-shaped grooves 411, the creepage distance between adjacent busbars 21 can be increased, thereby improving the safety of the battery pack 4 in the normal working state.

[0082] When one bracket 40 covers one battery module 10, the number of strip-shaped groove groups 41 on one bracket 40 is two columns, which are respectively used to assemble two columns of busbars 21. In the width direction Y of the battery pack 4, the two columns of strip-shaped groove groups 41 are located on both sides of the pressure relief valves 113 of the multiple battery cells 11 of the battery module 10. In some embodiments, the bracket 40 is further provided with a strip-shaped limiting groove 42 extending along the length direction X of the battery pack 4, and the two columns of strip-shaped groove groups 41 are located on both sides of the limiting groove 42. That is, in the height direction Z of the battery pack 4, the limiting groove 42 is located above the pressure relief valves 113 of the multiple battery cells 11. The limiting groove 42 is used to install a flexible circuit board 50 (Flexible Printed Circuit, FPC) (such asFigure 3 )。

[0083] When a bracket 40 covers multiple battery modules 10 at the same time, the number of strip groove groups 41 is greater than two columns. However, in the width direction Y of the battery pack 4, strip groove groups 41 are provided on both sides of each limiting groove 42, and two columns of limiting groove 42 groups are provided between adjacent two limiting grooves 42.

[0084] Specifically, in order to detect the state of the battery cells 11 in the battery pack 4, such as detecting parameters such as the temperature, voltage, current, etc. of the battery cells 11 in the battery pack 4 to determine whether the state in the battery pack 4 is normal. The battery pack 4 in the embodiment of the present application includes a flexible circuit board 50, which is respectively connected to multiple battery cells 11 through the flexible circuit board 50. For example, multiple battery cells 11 of each battery module 10 can be connected through a flexible circuit board 50 to detect the state of the multiple battery cells 11 of the battery module 10.

[0085] Refer to Figures 4 - 8 , in order to make full use of the space at the position directly opposite in the height direction Z of the battery pack 4 of the pressure relief valves 113 of multiple battery cells 11, in some embodiments, the flexible circuit board 50 is arranged at the position directly opposite to the pressure relief valve 113. For example, the flexible circuit board 50 is arranged in the limiting groove 42, so as to make full use of the space at the position directly opposite in the height direction Z of the pressure relief valves 113 of multiple battery cells 11 in the battery pack 4, which is beneficial to the miniaturization design of the battery pack 4. In addition, since the first isolation belts 31 are covered on the busbars 21 on both sides of the flexible circuit board 50, when the gas ejected from the pressure relief valve 113 of the battery cell 11 breaks through the flexible circuit board 50 and makes the wire debris in the flexible circuit board 50 fly around, through the isolation of the first isolation belt 31, the wire debris will not contact the busbar 21, thereby avoiding the short circuit between multiple busbars 21.

[0086] For each battery module 10, the two columns of busbars 21 on its multiple battery cells 11 are respectively located on both sides of the pressure relief valve 113, so the two columns of busbars 21 are far apart. Even when the battery cell 11 is out of control thermally, the expansion of the battery cell 11 basically will not cause the two columns of busbars 21 to contact and short circuit. However, the distance between the busbars 21 on adjacent two battery modules 10 is usually relatively small. When the battery cell 11 deforms due to thermal runaway, it is very easy to cause the busbars 21 on adjacent two battery modules 10 to contact and short circuit. In order to avoid the short circuit problem between the busbars 21 on adjacent battery modules 10. Refer to Figures 4 - 8, in some embodiments, some of the plurality of first isolation strips 31 include two integrally formed parts. One part 311 covers the surface 211 of the bus bar 21 facing away from the plurality of battery cells 11, and the other part 312 covers the surface 212 of the bus bar 21 facing away from the pressure relief valve 113. That is, one part 311 covers the surface 211 of the bus bar 21 facing away from the plurality of battery cells 11, and the other part 312 is located between two adjacent bus bars 21 on two adjacent battery modules 10. Thus, the space between two adjacent bus bars 21 on two adjacent battery modules 10 is covered by the other part 312 of the first isolation strip 31. Therefore, even if the battery cells 11 expand and drive the bus bar 21 to move, due to the isolation of the other part 312 of the first isolation strip 31, short circuit between the adjacent bus bars 21 on two adjacent battery modules 10 will not occur.

[0087] Referring to Figures 4 - 8 , in some embodiments, the first isolation strip 31 includes two integrally formed parts. One part 311 covers the bus bar 21, and the other part 312 extends from the bus bar 21 to cover part or all of the side walls 114 of the plurality of battery cells 11. The side walls 114 of the plurality of battery cells 11 are the surfaces adjacent to the surface 115 where the pole posts 101 are located. Thus, after two adjacent battery modules 10 are arranged, the other part 312 of the first isolation strip 31 is located between the relatively arranged side walls of two adjacent battery modules 10. Furthermore, there is the other part 312 of the first isolation strip 31 between two adjacent bus bars 21 on the plurality of battery cells 11 of two adjacent battery modules 10. Therefore, even if the battery cells 11 expand and drive the bus bar 21 to move, due to the isolation of the other part 312 of the first isolation strip 31, short circuit between the adjacent bus bars 21 on two adjacent battery modules 10 will not occur, improving the safety performance of the battery pack.

[0088] In order to make the first isolation strip 31 stably cover the bus bar 21, referring to Figures 4 - 8 , in some embodiments, the first isolation strip 31 is fixed to the bracket 40. By fixing the first isolation strip 31 on the bracket 40, and the bus bar 21 is arranged in the strip-shaped groove 411 of the bracket 40, the relative position between the first isolation strip 31 and the bus bar 21 can be kept fixed, so that the first isolation strip 31 stably covers the bus bar 21.

[0089] Referring to Figures 4 - 8, in some embodiments, the bracket 40 further includes a plurality of fixing platforms 43. The plurality of fixing platforms 43 are arranged at intervals in the strip-shaped groove 411 along the length direction X of the battery pack 4. Fixing holes 431 are provided on each of the plurality of fixing platforms 43, and the fixing holes 431 are used to fix the first isolation strip 31. Specifically, for example, the first isolation strip 31 and the bracket 40 can be fixedly connected by means of the cooperation of rivets and the fixing holes 431. By fixing the first isolation strip 31 through the plurality of fixing holes 431 on the plurality of fixing platforms 43, the fixing stability of the first isolation strip 31 can also be improved.

[0090] Referring to Figures 4 - 8 , in some embodiments, the fixing platform 43 is located between two adjacent busbars 21, that is, the two adjacent busbars 21 are separated in the length direction X of the battery pack 4 by the fixing platform 43, so as to increase the creepage distance between the two adjacent busbars 21 and improve the safety performance.

[0091] It should be noted that the two adjacent busbars 21 on two adjacent battery modules 10 in the above text refer to the busbar 21 on one battery module 10 and the busbar 21 on another adjacent battery module 10 are in an adjacent relationship.

[0092] In some embodiments, the number of brackets 40 is multiple. In the height direction Z of the battery pack 4, a bracket 40 is provided on one side of each battery module 10 facing the top wall 71 of the housing 7. In the width direction Y of the battery pack 4, the multiple brackets 40 are arranged at intervals, and another part 312 of the first isolation strip 31 is located between two adjacent brackets 40. Since another part 312 of the first isolation strip 31 is located between two adjacent brackets 40, in a high-temperature environment, even if the bracket 40 melts, there is still another part 312 of the first isolation strip 31 between the adjacent busbars 21 on two adjacent battery modules 10, so that a short circuit between the adjacent busbars 21 on two adjacent battery modules 10 can be effectively avoided.

[0093] Figure 9 For Figure 1 Schematic diagram of the decomposition structure of the battery module 10 in the battery pack 4 in the embodiment.

[0094] By providing the first isolation strip 31, the risk of short - circuit between multiple busbars 21 due to the housing 7 can be effectively reduced. It can also effectively reduce the risk of short - circuit between multiple busbars 21 due to impurities ejected from the pressure relief valve 113 of the battery cells 11. Moreover, it can reduce the risk of short - circuit between adjacent busbars 21 on adjacent battery modules 10 caused by deformation. In addition, there are other short - circuit risks in the battery pack 4. For example, in the related art, in order to prevent short - circuit between the battery cells 11 of two adjacent battery modules 10, since mica sheets are heat - resistant and insulating, mica sheets are usually provided between two adjacent battery modules 10. Through the mica sheets, short - circuit between the battery cells 11 of two adjacent battery modules 10 can be avoided. However, when the battery cell 11 expands due to thermal runaway, since the mica sheet is a hard material and is relatively brittle itself, the mica sheet will break when being squeezed by the expansion of the battery cell 11, which will then lead to the insulation failure between the battery cells 11 of adjacent battery modules 10, thus greatly increasing the risk of short - circuit. Also, since the mica sheet will lose its insulation property after getting wet and is extremely difficult to dry after getting wet, after fire - fighting operations, the battery pack 4 with mica sheets cannot be quickly put into use.

[0095] To solve the above problems, referring to Figure 2 、 Figure 3 、 Figure 5 and Figure 9 In some embodiments, the battery pack 4 further includes a second isolation strip 32. The second isolation strip 32 is flexible, heat - resistant and insulating, and the temperature that the second isolation strip 32 can withstand is within 1000 degrees Celsius. That is to say, when the temperature is within 1000 degrees Celsius, the second isolation strip 32 can still maintain its insulating and flexible properties.

[0096] A second isolation strip 32 is provided between two adjacent battery modules 10. The second isolation strip 32 is located between the oppositely arranged side walls of two adjacent battery modules 10. Since the second isolation strip 32 is heat - resistant, when one or some of the battery cells 11 have thermal runaway, the high temperature generated still cannot affect the performance of the second isolation strip 32. Thus, in a high - temperature environment, the insulation between the battery cells 11 of two adjacent battery modules 10 can still be ensured to prevent short - circuit between the battery cells 11 of two adjacent battery modules 10. Moreover, since the second isolation strip 32 is flexible, even in a high - temperature environment, when the battery cell 11 expands and squeezes the second isolation strip 32, the second isolation strip 32 cannot be damaged, effectively suppressing the spread and deterioration of thermal runaway of the battery cell 11.

[0097] In some embodiments, the second isolation strip 32 is a ceramic composite strip, so it is very easy to dry after being immersed in water. Thus, after fire - fighting operations on the battery pack 4, it is also very easy to dry and can continue to be used.

[0098] Since the second isolation strip 32 is flexible, it is necessary to reasonably fix the second isolation strip 32 so as to effectively play the role of the second isolation strip 32. In some embodiments, each of the plurality of battery modules 10 further includes end plates 12 provided at both ends in the arrangement direction of the plurality of battery cells 11 and tie straps 13 for bundling the plurality of battery cells 11 and the end plates 12; the plurality of battery cells 11 are bundled together by the tie straps 13 and the end plates 12 at both ends to facilitate handling and assembly.

[0099] Referring to Figure 2 、 Figure 3 、 Figure 5 and Figure 9 , on both sides of the battery module 10 in the width direction Y of the battery pack 4, second isolation strips 32 are provided, and the tie straps 13 bundle the second isolation strips 32 on two side surfaces of the plurality of battery cells 11 of the battery module 10 in the width direction Y of the battery pack 4. In this embodiment, when assembling the battery module 10, the second isolation strip 32 is bundled on two side surfaces of the battery module 10 in the width direction Y of the battery pack 4 by the tie straps 13, which not only realizes the reasonable fixation of the second isolation strip 32, but also eliminates the need for other fixing methods to fix the second isolation strip 32 during the subsequent installation between the plurality of battery modules 10, reducing the installation difficulty between the subsequent plurality of battery modules 10. In addition, since the tie straps 13 are usually metal tie straps 13 and the insulating coatings on the tie straps 13 are usually not heat-resistant, the second isolation strip 32 is provided between the plurality of battery cells 11 and the tie straps 13, so that in a high-temperature environment, even if the insulating coatings on the tie straps 13 melt and fail, the second isolation strip 32 can effectively prevent the short circuit between the plurality of battery cells 11 through the tie straps 13.

[0100] It can be understood that the second isolation strips 32 can be bundled on both side surfaces of the plurality of battery modules 10 in the width direction Y of the battery pack 4 in the embodiments of the present application by the tie straps 13.

[0101] In order to further improve the protection ability of the first isolation strip 31 and the second isolation strip 32 against short circuit phenomena in the battery pack 4, in some embodiments, in the height direction Z of the battery pack 4, the second isolation strip 32 extends to contact the first isolation strip 31, so that a part of the second isolation strip 32 extends between adjacent busbars 21 of adjacent battery modules 10, thereby avoiding the problem of short circuit between adjacent busbars 21 on adjacent battery modules 10.

[0102] In some embodiments, the first isolation strip 31 and the second isolation strip 32 can be integrally formed. During assembly, first fix the second isolation strip 32 on both sides of the battery module 10 in the width direction Y of the battery pack 4 through the cable tie 13. Then assemble multiple battery modules 10 into the lower box body 7b. Then install the bracket 40 on the side of the battery module 10 facing the top wall 71 of the housing 7. Next, install multiple busbars 21 in the multiple strip-shaped grooves 411 of the bracket 40. Then cover the first isolation strip 31 on the multiple busbars 21 and fix it to the bracket 40 or the busbar 21. This method can effectively prevent impurities from contacting the busbar 21 or the battery cell 11 through the contact between the first isolation strip 31 and the second isolation strip 32, thereby effectively reducing the probability of further deterioration after the thermal runaway of the battery cell 11.

[0103] In some embodiments, the number of brackets 40 is multiple. In the height direction Z of the battery pack 4, one bracket 40 is provided on the side of each battery module 10 facing the top wall 71 of the housing 7. In the width direction Y of the battery pack 4, the multiple brackets 40 are arranged at intervals, and a part of the second isolation strip 32 extends between two adjacent brackets 40. Since a part of the second isolation strip 32 extends between two adjacent brackets 40, even if the bracket 40 melts in a high-temperature environment, there is still the second isolation strip 32 between the adjacent busbars 21 on the adjacent battery modules 10, thereby effectively preventing a short circuit between the adjacent busbars 21 on the adjacent battery modules 10.

[0104] To further reduce the risk of short circuit in the battery pack 4, refer to Figure 2 、 Figure 3 and Figure 7 In some embodiments, the battery pack 4 further includes a third isolation strip 33. The third isolation strip 33 is flexible, high-temperature resistant and insulating, and the temperature range that the third isolation strip 33 can withstand is within 1000 degrees Celsius. That is to say, when the temperature is within 1000 degrees Celsius, the third isolation strip 33 can still maintain its insulating and flexible properties.

[0105] The third isolation strip 33 is arranged between the cable tie 13 and the end plate 12, so as to prevent the electrical connection between the cable tie 13 and the end plate 12 in a high-temperature environment, and the short circuit between the end plate 12 and the battery cell 11, which may lead to the short circuit problem between the battery cells 11.

[0106] The third isolation strip 33 can be arranged between the end plate 12 and the battery cell 11 to prevent the electrical connection between the battery cell 11 and the end plate 12 in a high-temperature environment.

[0107] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery pack, characterized in that, The battery pack includes a housing, a battery module, a plurality of busbars, and an insulating first isolation strip received in the housing; The battery module includes a plurality of battery cells arranged along the length direction of the battery pack. The plurality of busbars are provided on the surfaces where the pole columns of the plurality of battery cells are located. Two adjacent battery cells among the plurality of battery cells are electrically connected through one of the plurality of busbars. The plurality of busbars are arranged in the length direction of the battery pack; The first isolation strip extends along the length direction of the battery pack and covers the surfaces of the plurality of busbars facing away from the plurality of battery cells; there is a gap between the first isolation strip and the pressure relief valves of the plurality of battery cells in the direction of the interval between the pole column and the pressure relief valve.

2. The battery pack according to claim 1, characterized in that, Two rows of busbars are provided on the surfaces where the pole columns of the plurality of battery cells are located. In the direction of the interval between the pole column and the pressure relief valve, the two rows of busbars are located on both sides of the pressure relief valves of the plurality of battery cells. Each row of the two rows of busbars includes the plurality of busbars arranged at intervals along the length direction of the battery pack; Two of the first isolation strips respectively cover the two rows of busbars; in the direction of the interval between the pole column and the pressure relief valve, the two first isolation strips are respectively located on both sides of the pressure relief valves of the plurality of battery cells.

3. The battery pack according to claim 2, wherein, Each of the plurality of busbars has a long strip-shaped structure extending along the length direction of the battery pack, and each busbar is completely covered by the first isolation strip; in the length direction of the battery pack, the length of the first isolation strip is greater than or equal to the length after the plurality of battery cells are arranged; In the direction of the interval between the pole column and the pressure relief valve, the width of the first isolation strip is greater than or equal to the width of the busbar.

4. The battery pack according to any one of claims 1-3, characterized in that, The first isolation strip includes two integrally formed parts. One part covers the busbar, and the other part extends from the busbar to the side walls of the plurality of battery cells and covers part or all of the side walls. The side walls of the plurality of battery cells are the surfaces adjacent to the surface where the pole column is located.

5. The battery pack according to any one of claims 1 to 3, characterized in that The first isolation strip is a flexible structure, and the surfaces of the plurality of busbars facing away from the plurality of battery cells are in contact with the first isolation strip.

6. The battery pack according to any one of claims 1 to 3, characterized in that, The first isolation strip has insulating properties in both the normal state and the thermal runaway state of the battery cell.

7. The battery pack according to claim 6, wherein The first isolation strip has insulating properties in the temperature range less than 1000 °C.

8. The battery pack according to claim 3, characterized in that, The battery pack further includes a bracket provided on the surfaces where the pole columns of the plurality of battery cells are located. The bracket includes a strip-shaped groove extending along the length direction of the battery pack. The plurality of busbars are provided in the strip-shaped groove, and the first isolation strip is fixed to the bracket.

9. The battery pack according to claim 8, wherein, The bracket further includes a plurality of fixing platforms arranged at intervals along the length direction of the battery pack in the strip-shaped groove. Fixing holes are provided on the plurality of fixing platforms, and the fixing holes are used for fixing with the first isolation strip.

10. The battery pack according to claim 8, characterized in that, The number of the brackets is multiple, and the number of the battery modules is multiple. In the height direction of the battery pack, one bracket is provided on one side of each battery module facing the top wall of the housing. In the width direction of the battery pack, the multiple brackets are arranged at intervals. The first isolation strip is a flexible structure, and a part of the first isolation strip is located between two adjacent brackets.

11. The battery pack according to any one of claims 1 to 3, characterized in that, The bus bar includes multiple bottom plates electrically connected to the pole columns of the multiple battery cells and an arched plate integrally formed between two adjacent bottom plates among the multiple bottom plates. In the height direction of the battery pack, the arched plate is higher than the bottom plates, and fixing holes are provided on the bottom plates, and the fixing holes are used for fixing with the first isolation strip.

12. The battery pack according to any one of claims 1-3, characterized in that, The battery pack further includes multiple flexible and insulating second isolation strips; The number of the battery modules is multiple, and the multiple battery modules are arranged along the width direction of the battery pack. The second isolation strip is provided between two adjacent battery modules, and the second isolation strip is located between the oppositely arranged side walls of the two adjacent battery modules.

13. The battery pack according to claim 12, wherein, The multiple battery modules further each include end plates provided at both ends in the arrangement direction of the multiple battery cells and tie straps for bundling the multiple battery cells and the end plates; in the width direction of the battery pack, the second isolation strips are provided on both sides of the battery module, and the tie straps bundle the second isolation strips on two side surfaces of the multiple battery cells in the width direction of the battery pack.

14. An energy storage cabinet, characterized in that, The energy storage cabinet includes a cabinet and one or more battery packs according to any one of claims 1-13 above, and the one or more battery packs are provided in the cabinet.

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