Battery cell, battery pack and energy storage system

Abstract

The utility model provides a battery cell, a battery pack and an energy storage system. The battery cell comprises a shell, a heat insulation sheet and at least one core bag, the shell comprises a plurality of side plates which define a containing cavity, and the core bag is located in the containing cavity. The shell is provided with an anti-explosion valve, and the anti-explosion valve is located on any one of the side plates. And the heat insulation sheet is at least partially positioned between the at least one core package and the shell. The part, located between the at least one core package and the shell, of the heat insulation sheet is arranged towards at least one side plate, not provided with the anti-explosion valve, of the multiple side plates. When the battery cell is in thermal runaway, the heat insulation sheet can prevent heat of the cell package from melting through the shell, so that the explosion-proof valve is timely opened by air pressure in the battery cell, and the safety of the battery cell is improved. Besides, heat transfer between the core package and the shell is blocked by the heat insulation sheet, and meanwhile, heat in the heat insulation sheet can be uniformly distributed, so that part of heat, facing the heat insulation sheet, of the core package is uniformly distributed, overhigh local heat of the core package is avoided, and the service life of the battery cell is further prolonged.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery pack and an energy storage system. Background Art

[0002] Lithium batteries have the characteristics of high energy density and long cycle life, and are widely used in energy storage, electric vehicles, and backup power. The battery pack of lithium batteries generates a lot of heat during the charging and discharging process. Overheating will accelerate the side reactions of the battery cells inside the battery pack, reducing the performance and service life of the battery. In order to prevent the battery cells from catching fire or even exploding during thermal runaway, an explosion-proof valve is usually provided on the top of the battery cell to release high-temperature gas and electrolyte to avoid battery cell explosion. However, when the temperature inside the battery cell gradually rises, part of the heat of the core pack may be transferred to the battery cell shell from the bottom or side, which is easy to melt through the battery cell shell, causing the heat to spread between the batteries in the battery pack, thereby causing safety accidents. In addition, after part of the heat of the core pack is dissipated through the battery cell shell, the air pressure inside the battery cell cannot reach the conditions for opening the explosion-proof valve, so that the explosion relief function cannot be realized in time, which is not conducive to the safety of the battery pack. Utility Model Content

[0003] The present application provides a battery cell, a battery pack, and an energy storage system to block heat transfer between the battery cell pack and the shell, thereby preventing the battery cell from melting through the battery cell shell when thermal runaway occurs, and allowing the internal air pressure of the battery cell to open the explosion-proof valve in time, thereby improving the thermal safety of the battery pack.

[0004] In a first aspect, the present application provides a battery cell. The battery cell includes a shell, a thermal insulation sheet and at least one core package. Specifically, the shell includes a plurality of side panels, and the plurality of side panels can enclose a receiving cavity, and the at least one core package is located in the receiving cavity. In addition, the shell is provided with an explosion-proof valve, and the explosion-proof valve is located on any one of the plurality of side panels. The thermal insulation sheet is at least partially located between the at least one core package and the shell. Among them, the portion of the thermal insulation sheet located between the at least one core package and the shell is arranged toward at least one side panel among the plurality of side panels on which the explosion-proof valve is not provided.

[0005] The battery cell of the present application is provided with an explosion-proof valve, which is used to release high-temperature gas and electrolyte to avoid explosion of the battery cell during thermal runaway. The heat insulation sheet inside the battery cell can thermally isolate the core package from the shell to improve the phenomenon of heat from the core package spreading to the shell. In this way, when thermal runaway occurs in the battery cell, the heat insulation sheet can prevent the heat of the core package from melting through the shell on the one hand, and the heat insulation can ensure that the internal air pressure of the battery cell can open the explosion-proof valve in time on the other hand, thereby improving the safety of the battery cell. In addition, since the inside of the heat insulation sheet has thermal conductivity, while blocking the heat transfer between the core package and the shell, the heat inside the heat insulation sheet is evenly transferred to various parts of the heat insulation sheet, so that the heat distribution of the part of the core package facing the heat insulation sheet can be more uniform, so as to avoid excessive local heat of the core package, thereby improving the service life of the battery cell.

[0006] In order to enable the heat shield to block high temperature when the battery core has thermal runaway, the melting point of the heat shield may be greater than or equal to 200 degrees. Further, in a possible embodiment, the melting point of the heat shield may be greater than or equal to 400 degrees.

[0007] In a possible implementation, an insulating film is further provided on the outer surface of each core package in the at least one core package. The insulating film is located between each core package and the thermal insulation sheet. Alternatively, the insulating film may include two layers of film, and the thermal insulation sheet is located between the two layers of film, that is, the thermal insulation sheet may be combined with the insulating film and cover the core package together with the insulating film.

[0008] In the battery cell of the present application, the thermal insulation sheet includes at least one of a copper sheet, a tungsten sheet, a molybdenum sheet, a nickel-based metal sheet, an iron-based metal sheet, a cobalt-based metal sheet, an aluminum oxide ceramic sheet, a silicon oxide ceramic sheet, and a zirconium oxide ceramic sheet.

[0009] The surface of the thermal insulation sheet facing the at least one core package is covered with an insulating layer, that is, the thermal insulation sheet can play a role of heat insulation and also play a role of insulation.

[0010] The thermal insulation sheet is at least partially located between the core package and the shell. The thermal insulation sheet can be completely located between the core package and the shell, or can also be partially located between the core package and the shell.

[0011] In a possible implementation, the heat insulation sheet is located between the at least one core package and the shell. In this technical solution, the heat insulation sheet can be arranged opposite to at least one surface of the at least one core package. For example, the heat insulation sheet can be a flat heat insulation sheet, and the at least one core package is located on one side of the flat heat insulation sheet, wherein the one side surface and the flat heat insulation sheet can be planes, or the one side surface and the flat heat insulation sheet can be circular rings. Of course, in order to further improve the heat barrier effect, the heat insulation sheet can also be arranged opposite to multiple surfaces of the at least one core package. Alternatively, the heat insulation sheet can also be an L-shaped heat insulation sheet, and the two adjacent surfaces of the at least one core package are respectively arranged toward the two side surfaces of the L-shaped heat insulation sheet. In other words, the heat insulation sheet can be arranged opposite to the two surfaces of the core package. Alternatively, the heat insulation sheet can also be a U-shaped heat insulation sheet, and the at least one core package is located in the U-shaped heat insulation sheet. In other words, the three side surfaces of the heat insulation sheet can be arranged opposite to the three surfaces of the core package. Alternatively, the heat insulation sheet can also be an annular heat insulation sheet, and the at least one core package is located in the annular heat insulation sheet. That is to say, when the core package is a square core package, the heat insulation sheet can be a square ring-shaped heat insulation sheet, and the four sides of the heat insulation sheet are arranged opposite to the four surfaces of the core package. Alternatively, the heat insulation sheet can also be a cylindrical heat insulation sheet, and the above-mentioned at least one core package is located in the cylindrical heat insulation sheet. That is to say, when the core package is a cylindrical core package, the heat insulation sheet is cylindrical, and the annular side surface and one end surface of the core package are respectively arranged opposite to the heat insulation sheet; when the core package is a square core package, the heat insulation sheet is square cylindrical, and the five surfaces of the core package are respectively arranged opposite to the five sides of the heat insulation sheet.

[0012] In another possible implementation, the at least one core package may include two core packages. The thermal insulation sheet includes a core package spacer and at least one end spacer. The core package spacer is located between the two core packages, and the at least one end spacer is located at the end of the core package spacer and between the two core packages and the shell. In other words, a portion of the thermal insulation sheet is located between the core package and the shell, and another portion is located between the core package and the core package. In this way, the thermal insulation sheet can not only block the heat spread between the core package and the shell, but also block the heat spread between the core package and the core package, thereby preventing heat from spreading between the core packages.

[0013] In a possible implementation, the at least one end spacer may include an end spacer, the end spacer is located on one side of the two core packages, and the end spacer is arranged in a T-shape with the core package spacer. That is, in the two core packages, the two surfaces of each core package are arranged opposite to the thermal insulation sheet. Or, in another possible implementation, the at least one end spacer may include two end spacers, the two end spacers are arranged opposite to each other at the two ends of the core package spacer, and the two end spacers are arranged in an I-shape with the core package spacer. In this way, a part of the two end spacers and a side surface of the core package spacer enclose a U-shaped space, and one of the two core packages is at least partially located in the U-shaped space, that is, the three surfaces of the one core package are arranged opposite to the thermal insulation sheet. Another part of the end spacer and the other side surface of the core package spacer enclose another U-shaped space, and the other core package of the two core packages is at least partially located in the other U-shaped space, that is, the three surfaces of the other core package are arranged opposite to the thermal insulation sheet. Alternatively, in another possible implementation, the at least one end spacer may include three end spacers, which are connected in sequence in a U shape, and the core package spacer is arranged perpendicular to the three end spacers. A portion of the three end spacers and a side surface of the core package spacer form a receiving space, and one of the two core packages is located in the receiving space. Another portion of the three end spacers and another side edge of the core package spacer form another receiving space, and the other core package of the two core packages is located in the other receiving space. Therefore, in the two core packages, the four surfaces of each core package are respectively arranged opposite to the thermal insulation sheet.

[0014] In a possible implementation, the area of ​​the portion of the heat-insulating sheet between the at least one core package and the shell is greater than or equal to the area of ​​the at least one core package facing the portion. In other words, the projection of the heat-insulating sheet on the corresponding core package surface can completely cover the core package surface, further improving the heat-insulating effect between the core package surface and the shell.

[0015] In the second aspect, the present application provides a battery pack. The battery pack specifically includes an outer shell, and at least one battery cell of the first aspect described above, at least one battery cell is located in the outer shell, and the explosion-proof valve of at least one battery cell is arranged in the same direction. In the battery pack of the present application, the thermal insulation sheet inside the battery cell can thermally isolate the core package from the shell. In this way, when a thermal runaway occurs in the battery cell, on the one hand, the thermal insulation sheet can prevent the heat of the core package from melting through the shell, thereby preventing the heat from spreading between adjacent battery cells; on the other hand, the thermal barrier can ensure that the internal air pressure of the battery cell can open the explosion-proof valve in time, thereby improving the thermal safety of the battery pack. In addition, the thermal insulation sheet can also make the heat distribution inside the core package more uniform, thereby avoiding excessive local heat in the core package, and thus can increase the service life of the battery pack.

[0016] In the third aspect, the present application provides an energy storage system. The energy storage system includes the battery pack and the power converter of the second aspect above, and the power converter is used to convert the electric energy output by the external power supply into power and output it to the battery pack. Inside the battery pack of the energy storage system of the present application, the thermal insulation sheet can improve the heat transfer between the core pack and the battery cell shell to prevent the battery cell shell from being melted through. Moreover, when the air pressure inside the battery cell is too high, the explosion-proof valve can open and release high-temperature gas and electrolyte, thereby reducing the risks of short circuit and explosion of the battery pack, so as to improve the safety of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a battery pack provided in an embodiment of the present application;

[0018] Figure 2 A schematic diagram of a battery cell provided in an embodiment of the present application;

[0019] Figure 3 A schematic diagram of a core package, an insulating film and a heat-insulating sheet provided in an embodiment of the present application;

[0020] Figure 4 Another schematic diagram of the core package, the insulating film and the thermal insulation sheet provided in the embodiment of the present application;

[0021] Figure 5 A schematic diagram of a core package and a heat insulation sheet provided in an embodiment of the present application;

[0022] Figure 6 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application;

[0023] Figure 7 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application;

[0024] Figure 8 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application;

[0025] Fig. 9 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application;

[0026] Fig.10 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application;

[0027] Fig.11 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application;

[0028] Fig.12 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application;

[0029] Fig.13Another schematic diagram of the core package and thermal insulation sheet provided in an embodiment of the present application.

[0030] Reference numerals:

[0031] 10-Battery Pack

[0032] 11- Shell

[0033] 12-Battery Cell

[0034] 121-Shell

[0035] 122-Explosion-proof valve

[0036] 123-Thermal insulation sheet

[0037] 124-Core Package

[0038] 125-Positive column

[0039] 126-Negative column

[0040] 127-Insulation film

[0041] 1231-Core spacer

[0042] 1232-End spacer

[0043] 1271-a layer of membrane

[0044] 1272-Another membrane DETAILED DESCRIPTION

[0045] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings.

[0046] In order to facilitate the understanding of the battery cells, battery packs and energy storage systems provided in the embodiments of the present application, their application scenarios are explained below. The energy storage system of the present application can be used in multiple application scenarios of industrial and commercial energy storage and power station energy storage. Industrial and commercial energy storage may, for example, include small-scale industrial and commercial (small factories, etc.) energy storage, medium-sized industrial and commercial energy storage, large-scale industrial and commercial energy storage, photovoltaic storage and charging station energy storage, small and medium-sized microgrid (islands, etc.) energy storage, etc. Power station energy storage may, for example, include wind and solar storage power stations, power grid storage power stations, large microgrid power stations, etc. In addition, energy storage equipment can also be used in application scenarios such as data centers and vehicle charging stations. The energy storage device contains a power converter and at least one battery pack, and the power converter is used to convert the electric energy output by an external power supply and output it to the aforementioned at least one battery pack. Figure 1 A schematic diagram of a battery pack provided in an embodiment of the present application. Figure 1As shown, the battery pack 10 may include a housing 11, which contains a power module (not shown) and at least one battery cell 12. In the present application, the housing 121 of the battery cell 12 is provided with an explosion-proof valve 122. When the internal gas pressure of the battery cell 12 is too high, the explosion-proof valve 122 opens to release high-temperature gas and electrolyte to prevent the battery cell 12 from exploding.

[0047] However, inside the battery cell, when the heat of the core pack gradually increases, the heat of the core pack will spread to the battery cell shell, causing the battery cell shell to be melted through, resulting in heat spreading between multiple battery cells in the battery pack. In addition, the heat transfer between the battery cell and the battery cell shell causes the internal air pressure of the battery cell to drop, and the explosion-proof valve cannot be opened in time, thereby causing a safety accident. Therefore, the present application provides a battery cell, a battery pack, and an energy storage system to block the heat transfer between the core pack and the shell in the battery cell, thereby preventing the battery cell from melting through the battery cell shell when thermal runaway occurs, and allowing the internal air pressure of the battery cell to open the explosion-proof valve in time, thereby improving the thermal safety of the battery pack.

[0048] It should be noted that the terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be limiting of the present application. As used in the specification and appended claims of the present application, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear indication to the contrary in the context.

[0049] References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0050] Please continue reading Figure 1 In the battery pack 10 of the present application, the explosion-proof valve 122 of the at least one battery cell 12 is arranged in the same direction, such as Figure 1 Middle towards the top setting. Figure 2 Schematic diagram of a battery cell provided in an embodiment of the present application. Figure 1 and Figure 2As shown, in each battery cell 12 of the battery pack 10, the battery cell 12 includes a shell 121, a heat insulating sheet 123 and at least one core package 124. Specifically, the shell 121 includes a plurality of side panels, and the plurality of side panels can enclose a receiving cavity, and the at least one core package 124 is located in the receiving cavity. In an embodiment of the present application, the shell 121 may be a square shell, and the plurality of side panels include six flat plates, and the six flat plates enclose a square receiving cavity. Alternatively, the shell 121 may also be a cylindrical shell, and the plurality of side panels include two flat plates arranged opposite to each other, and an annular plate connected between the two flat plates, and the two flat plates and the annular plate enclose a cylindrical receiving cavity. In addition, the core package 124 may be a winding core package, or may be a laminated core package, which is not limited in the present application.

[0051] In the battery cell 12 of the present application, the housing 121 is provided with a positive electrode column 125 and a negative electrode column 126, and any one of the positive electrode column 125 and the negative electrode column 126 is located on any one of the above-mentioned multiple side panels. The explosion-proof valve 122 is located on any one of the above-mentioned multiple side panels. In other words, the positive electrode column 125 or the negative electrode column 126 can be located on the same side panel as the explosion-proof valve 122, or the positive electrode column 125, the negative electrode column 126 and the explosion-proof valve 122 are located on the same side panel, or the explosion-proof valve 122 is located on any side panel where no electrode column is provided.

[0052] The heat insulating sheet 123 is used to block the heat transfer between the at least one core package 124 and the shell 121. When the heat insulating sheet 123 is specifically set, at least a portion of the heat insulating sheet 123 is located between the at least one core package 124 and the shell 121, and the portion of the heat insulating sheet 123 located between the at least one core package 124 and the shell 121 is arranged toward at least one side plate among the plurality of side plates on which the explosion-proof valve 122 is not arranged.

[0053] The battery cell 12 of the present application is provided with an explosion-proof valve 122, which is used to release high-temperature gas and electrolyte to prevent the battery cell 12 from exploding when it is in thermal runaway. The heat-insulating sheet 123 inside the battery cell 12 can thermally isolate the at least one core package 124 from the shell 121 to improve the phenomenon that the heat of the core package 124 spreads to the shell 121. In this way, when the battery cell 12 is in thermal runaway, the heat-insulating sheet 123 can prevent the heat of the core package 124 from melting through the shell 121 on the one hand, and the heat-insulating sheet 123 can ensure that the internal air pressure of the battery cell 12 can open the explosion-proof valve 122 in time, thereby improving the safety of the battery cell 12. In addition, since the interior of the thermal insulation sheet 123 is thermally conductive, while blocking the heat transfer between the core package 124 and the shell 121, the heat inside the thermal insulation sheet 123 is evenly conducted to various parts of the thermal insulation sheet 123. This allows the heat distribution of the part of the core package 124 facing the thermal insulation sheet 123 to be more uniform, thereby avoiding excessive local heat in the core package 124, thereby increasing the service life of the battery cell 12.

[0054] When the battery cell 12 is specifically assembled, the core package 124 is spaced apart from the shell 121 in the accommodating cavity of the shell 121, and the electrolyte is injected between the core package 124 and the shell 121. The surface of the heat insulating sheet 123 facing the core package 124 can be directly attached to the core package 124, or the heat insulating sheet 123 may not be attached to the core package 124. Similarly, the surface of the heat insulating sheet 123 facing the shell 121 can be directly attached to the inner wall of the shell 121, or the heat insulating sheet 123 may not be attached to the inner wall of the shell 121.

[0055] Figure 3 A schematic diagram of the core package, insulating film and thermal insulation sheet provided in the embodiment of the present application. Figure 3 As shown, in one embodiment, an insulating film 127 is further provided on the outer surface of each core package 124 of the at least one core package 124. The insulating film 127 may be a mylar film, which is used to wrap the positive electrode sheet, the negative electrode sheet and the separator of the core package 124 to prevent the active materials on the positive electrode sheet and the negative electrode sheet from falling off and to avoid electrochemical corrosion of the housing 121. The insulating film 127 is located between each core package 124 and the heat insulation sheet 123, that is, the heat insulation sheet 123 is provided on the outer surface of the insulating film 127. Figure 4 Another schematic diagram of the core package, insulating film and thermal insulation sheet provided in the embodiment of the present application. Figure 4 As shown, in another embodiment, the insulating film 127 may include two layers of films, wherein one layer of the two layers of films 1271 is arranged close to the core package 124, and the other layer of the film 1272 is located at the periphery of the one layer of the film 1271, and the thermal insulation sheet 123 is located between the two layers of films, that is, the thermal insulation sheet 123 can be combined with the insulating film 127 and together with the insulating film 127 cover the core package 124.

[0056] In the battery cell 12 of the present application, in order to enable the heat insulation sheet 123 to block high temperature when thermal runaway occurs in the battery cell 12, the heat insulation sheet 123 can be made of a high temperature resistant material, for example, the melting point of the heat insulation sheet 123 can be greater than or equal to 200 degrees. In a specific embodiment, the melting point of the heat insulation sheet 123 can be greater than or equal to 400 degrees, which can further improve the high temperature resistance of the heat insulation sheet 123.

[0057] Specifically, the heat insulating sheet 123 may include at least one of a copper sheet, a tungsten sheet, a molybdenum sheet, a nickel-based metal sheet, an iron-based metal sheet, a cobalt-based metal sheet, an aluminum oxide ceramic sheet, a silicon oxide ceramic sheet, and a zirconium oxide ceramic sheet. In addition to playing a role of heat insulation, the heat insulating sheet 123 may also play a role of insulation. Specifically, the surface of the heat insulating sheet 123 facing the at least one core package 124 is covered with an insulating layer, and the insulating layer may be made by coating or coating.

[0058] In the embodiment of the present application, the area of ​​the portion of the heat insulating sheet 123 located between the at least one core package 124 and the shell 121 is greater than or equal to the area of ​​the at least one core package 124 facing the portion. In other words, the projection of the heat insulating sheet 123 on the surface of the corresponding core package 124 can completely cover the surface of the core package 124, further improving the heat barrier effect between the surface of the core package 124 and the shell 121.

[0059] In the embodiment of the present application, the shape of the heat insulation sheet 123 can be specifically set according to the shape, position and quantity of the core package 124, which will be described in detail below.

[0060] It can be understood that the thermal insulation sheet 123 being at least partially located between the core package 124 and the shell 121 means that the thermal insulation sheet 123 can be completely located between the core package 124 and the shell 121, or the thermal insulation sheet 123 can also be partially located between the core package 124 and the shell 121.

[0061] In some embodiments, the heat insulation sheet 123 may be completely located between the core package 124 and the shell 121. Figure 2 As shown, the battery cell 12 may include a core package 124, and the heat insulation sheet 123 is arranged toward one surface of the core package 124. In other words, the heat insulation sheet 123 is located between the one surface of the core package 124 and a side plate of the shell 121. In one embodiment, the shell 121 may be a square shell, the core package 124 may be a square core package, and the heat insulation sheet 123 may be a planar heat insulation sheet, so that the one surface of the core package 124, the planar heat insulation sheet and the one side plate of the shell 121 are arranged in parallel. In another embodiment, the shell 121 may also be a cylindrical shell, the core package 124 may be a cylindrical core package, and the heat insulation sheet 123 may be a circular heat insulation sheet, so that the annular side surface of the cylindrical core package, the circular heat insulation sheet, and the annular side plate of the cylindrical shell are sequentially sleeved from the inside to the outside.

[0062] In the above embodiment, the heat insulating sheet 123 is disposed toward the side plate of the housing 121 where the explosion-proof valve 122 is not disposed. In one embodiment, the positive electrode column 125, the negative electrode column 126 and the explosion-proof valve 122 are disposed together at the top of the housing 121. The heat insulating sheet 123 may be disposed toward the bottom or any side of the housing 121.

[0063] like Figure 1 As shown, in another embodiment, the battery cell 12 may include a plurality of core packages 124. The plurality of core packages 124 include at least two rows of core packages 124 sequentially arranged along a first direction A, and each row of core packages 124 includes at least one core package 124 sequentially arranged along a second direction B, wherein the first direction A is perpendicular to the second direction B. Figure 5 A schematic diagram of the core package and the heat insulation sheet provided in the embodiment of the present application. Figure 5As shown, in one embodiment, the thermal insulation sheet 123 can be arranged perpendicular to the first direction A, that is, in a row of core packages 124 located at the end of the above-mentioned multiple core packages 124, a surface of each core package 124 is arranged opposite to the thermal insulation sheet 123. Figure 6 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application. Figure 6 As shown, in another embodiment, the thermal insulation sheet 123 may also be arranged perpendicular to the second direction B, that is, in each column of core packages 124 of the above-mentioned multiple core packages 124, a surface of a core package 124 located at the same side end is arranged opposite to the thermal insulation sheet 123. Figure 7 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application. Figure 7 As shown, in another embodiment, the thermal insulation sheet 123 can also be arranged parallel to the plane where the first direction A and the second direction B are located, that is, a surface (top surface or bottom surface) of each core package 124 of the above-mentioned multiple core packages 124 is arranged opposite to the thermal insulation sheet 123.

[0064] In the above embodiment, when the thermal insulation sheet 123 is a planar thermal insulation sheet, the number of thermal insulation sheets 123 inside the battery cell 12 is not limited. For example, the battery cell 12 may include one thermal insulation sheet 123, two thermal insulation sheets 123, three thermal insulation sheets 123, four thermal insulation sheets 123 or five thermal insulation sheets 123.

[0065] Of course, in order to further improve the heat-blocking effect, the heat-insulating sheet 123 may also be disposed opposite to multiple surfaces of the at least one core package 124 . Figure 8 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application. Figure 8 As shown, in another embodiment, the heat insulation sheet 123 may also be an L-shaped heat insulation sheet, and the two adjacent surfaces of the at least one core package 124 are respectively arranged toward the two sides of the L-shaped heat insulation sheet. The heat insulation sheet 123 may be arranged opposite to the two surfaces of the core package 124. The heat insulation sheet 123 may be arranged opposite to the two surfaces of the core package 124.

[0066] Fig. 9 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application. Fig. 9 As shown, in another embodiment, the heat insulation sheet 123 may also be a U-shaped heat insulation sheet, and the at least one core package 124 is located inside the U-shaped heat insulation sheet. That is, the three side surfaces of the heat insulation sheet 123 may be arranged opposite to the three surfaces of the core package 124. Alternatively, the heat insulation sheet 123 may also be a square ring-shaped heat insulation sheet, and the at least one core package 124 may be a square core package and located inside the square ring-shaped heat insulation sheet.

[0067] In another embodiment, the heat insulation sheet 123 may also be a cylindrical heat insulation sheet, and the at least one core package 124 is located inside the cylindrical heat insulation sheet. That is, when the core package 124 is a cylindrical core package, the heat insulation sheet 123 is cylindrical, and the annular side surface and one end surface of the core package 124 are respectively arranged opposite to the heat insulation sheet 123; when the core package 124 is a square core package, the heat insulation sheet 123 is square cylindrical, and the five surfaces of the core package 124 are respectively arranged opposite to the five side surfaces of the heat insulation sheet 123.

[0068] The at least one core package 124 may include a plurality of core packages 124. In other embodiments, a portion of the heat insulating sheet 123 may be located between two adjacent core packages 124, and another portion may be located between the core package 124 and the shell 121. Fig.10 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application. Fig.10 As shown, taking the example that the at least one core package 124 includes two core packages 124, the heat insulation sheet 123 includes a core package spacer 1231 and at least one end spacer 1232. Among them, the core package spacer 1231 is located between the two core packages 124, and the at least one end spacer 1232 is located at the end of the core package spacer 1231 and between the two core packages 124 and the shell 121. In this way, the heat insulation sheet 123 can not only block the heat spread between the core package 124 and the shell 121, but also block the heat spread between the core packages 124 and the core packages 124, thereby preventing heat from spreading between the multiple core packages 124. Of course, in the embodiment of the present application, the specific number of the core package spacers 1231 can be determined according to the number of the core packages 124. For example, in one embodiment, among the multiple core packages 124, a core package spacer 1231 can be provided between any two adjacent core packages 124. In this embodiment, a plurality of core package spacers 1231 may be independently provided, or the core package spacers 1231 may be connected to form an integral structure.

[0069] Please continue reading Fig.10 In one embodiment, the at least one end spacer 1232 may include one end spacer 1232, the one end spacer 1232 is located on one side of the two core packages 124, and the one end spacer 1232 and the core package spacer 1231 are arranged in a T-shape. That is, in the two core packages 124, the two surfaces of each core package 124 are arranged opposite to the two side surfaces of the heat insulation sheet 123 respectively.

[0070] Fig.11 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application. Fig.11As shown, in another embodiment, the at least one end spacer 1232 may include two end spacers 1232, which are arranged at opposite ends of the core package spacer 1231, and the two end spacers 1232 and the core package spacer 1231 are arranged in an I-shaped shape. In this way, a part of the two end spacers 1232 and a side surface of the core package spacer 1231 enclose a U-shaped space, and one of the two core packages 124 is at least partially located in the U-shaped space, that is, the three surfaces of the one core package 124 are respectively arranged opposite to the three side surfaces of the thermal insulation sheet 123. The other part of the end spacer 1232 and the other side surface of the core package spacer 1231 enclose another U-shaped space, and the other of the two core packages 124 is at least partially located in the other U-shaped space, that is, the three surfaces of the other core package 124 are respectively arranged opposite to the three side surfaces of the thermal insulation sheet 123.

[0071] Fig.12 Another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application, Fig.13 This is another schematic diagram of the core package and the thermal insulation sheet provided in the embodiment of the present application. Fig.12 and Fig.13 As shown, in another embodiment, the at least one end spacer 1232 may include three end spacers 1232, and the three end spacers 1232 are connected in sequence in a U shape, and the core package spacer 1231 is arranged perpendicular to the three end spacers 1232. A portion of the three end spacers 1232 and a side surface of the core package spacer 1231 form a receiving space, and one of the two core packages 124 is located in the one receiving space. Another portion of the three end spacers 1232 and the other side edge of the core package spacer 1231 form another receiving space, and the other of the two core packages 124 is located in the other receiving space. Therefore, in the two core packages 124, the four surfaces of each core package 124 are respectively arranged opposite to the four side surfaces of the thermal insulation sheet 123.

[0072] Based on the same technical concept, the present application also provides an energy storage system. The energy storage system includes a battery pack 10 and a power converter according to any of the above embodiments, and the power converter is used to convert the electric energy output by the external power supply and output it to the battery pack 10. In the energy storage system of the present application, inside the battery pack 10, the thermal insulation sheet 123 can improve the heat transfer between the core pack 124 and the shell 121 of the battery cell 12 to prevent the shell 121 from being melted through. In addition, when the air pressure inside the battery cell 12 is too high, the explosion-proof valve 1212 can open and release high-temperature gas and electrolyte, thereby reducing the risks of short circuit and explosion of the battery pack 10 to improve the safety of the energy storage system.

[0073] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery cell, characterized in that: It includes a shell, a heat insulation sheet and at least one core package, wherein: The shell includes a plurality of side plates, the plurality of side plates enclose a receiving cavity, and the at least one core package is located in the receiving cavity; The shell is provided with an explosion-proof valve, and the explosion-proof valve is located on any one of the multiple side plates; The heat insulation sheet is at least partially located between the at least one core package and the shell, and the portion of the heat insulation sheet located between the at least one core package and the shell is arranged toward at least one side plate among the plurality of side plates on which the explosion-proof valve is not arranged.

2. The battery cell according to claim 1, characterized in that: The melting point of the thermal insulation sheet is greater than or equal to 200 degrees.

3. The battery cell according to claim 1 or 2, characterized in that: The outer surface of each core package of the at least one core package is also provided with an insulating film; The insulating film is located between each core package and the thermal insulation sheet; or, the insulating film includes two layers of film, and the thermal insulation sheet is located between the two layers of film.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The thermal insulation sheet includes at least one of a copper sheet, a tungsten sheet, a molybdenum sheet, a nickel-based metal sheet, an iron-based metal sheet, a cobalt-based metal sheet, an aluminum oxide ceramic sheet, a silicon oxide ceramic sheet, and a zirconium oxide ceramic sheet.

5. The battery cell according to claim 4, characterized in that: The surface of the heat insulation sheet facing the at least one core package is covered with an insulation layer.

6. The battery cell according to any one of claims 1 to 5, characterized in that: An area of ​​the portion of the heat insulation sheet located between the at least one core package and the shell is greater than or equal to an area of ​​the portion of the at least one core package facing the portion.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The heat insulation sheet is located between the at least one core package and the shell; The thermal insulation sheet is a flat thermal insulation sheet, and the at least one core package is arranged on one side of the flat thermal insulation sheet; or, the thermal insulation sheet is an L-shaped thermal insulation sheet, and two adjacent surfaces of the at least one core package are respectively arranged toward two side surfaces of the L-shaped thermal insulation sheet; or, the thermal insulation sheet is a U-shaped thermal insulation sheet, and the at least one core package is located inside the U-shaped thermal insulation sheet; or, the thermal insulation sheet is an annular thermal insulation sheet, and the at least one core package is located inside the annular thermal insulation sheet; or, the thermal insulation sheet is a cylindrical thermal insulation sheet, and the at least one core package is located inside the cylindrical thermal insulation sheet.

8. The battery cell according to any one of claims 1 to 6, characterized in that: The at least one core package comprises two core packages; The thermal insulation sheet includes a core package spacer and at least one end spacer, wherein the core package spacer is located between the two core packages, and the at least one end spacer is located at the end of the core package spacer and between the two core packages and the shell.

9. The battery cell according to claim 8, characterized in that: The at least one end spacer comprises one end spacer, the one end spacer is located at one side of the two core packages and is arranged in a T-shape with the core package spacer; or, The at least one end spacer comprises two end spacers, and the two end spacers are arranged oppositely at two ends of the core package spacer and are arranged in an I-shape with the core package spacer; or, The at least one end spacer includes three end spacers, and the three end spacers are connected in sequence in a U shape, and the core package spacer is arranged perpendicular to the three end spacers; a part of the three end spacers and a side surface of the core package spacer form a accommodating space, and one of the two core packages is located in the one accommodating space; another part of the three end spacers and the other side of the core package spacer form another accommodating space, and the other core package of the two core packages is located in the other accommodating space.

10. A battery pack, characterized in that: The invention comprises a shell and at least one battery cell according to any one of claims 1 to 9, wherein at least one of the battery cells is located in the shell, and an explosion-proof valve of at least one of the battery cells is arranged in the same direction.

11. An energy storage system, characterized in that: The energy storage system comprises the battery pack and a power converter as claimed in claim 10, wherein the power converter is used to convert the electric energy output by an external power source and output it to the battery pack.

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