Battery cell and battery assembly comprising the same

Abstract

This disclosure relates to a battery cell and a battery assembly including the battery cell. The battery cell includes: an electrode assembly formed by alternatingly stacking a plurality of positive electrodes and a plurality of negative electrodes separated by separators along a predetermined direction; a positive electrode tab electrically connected to the plurality of positive electrodes at one end in a length direction perpendicular to the predetermined direction of the electrode assembly; a negative electrode tab electrically connected to the plurality of negative electrodes at the other end in the length direction of the electrode assembly; a pouch housing the electrode assembly internally, such that at least a portion of the positive electrode tab and at least a portion of the negative electrode tab are exposed externally; and a pressure pad attached to one side of the pouch perpendicular to the predetermined direction, the thickness of the pressure pad being variable according to the distance between it and the positive electrode tab and the distance between it and the negative electrode tab, the thickness being its length in a direction perpendicular to one side of the pouch. This disclosure can reduce the amount of lithium metal deposited at the negative electrode of the battery cell.

Description

Technical Field

[0001] This disclosure relates to a battery cell and a battery assembly including the battery cell, and more specifically to a battery cell with a pressure pad attached and a battery assembly including the battery cell. Background Technology

[0002] The pouch cell is constructed by surrounding an electrode assembly, including a positive electrode, a negative electrode, and a separator, with a pouch. However, due to the manufacturing method of the electrode assembly and the stacking method of the positive and negative plates, the thickness of the electrode assembly contained in the pouch is not constant and will have thickness deviation.

[0003] Specifically, in the electrode assembly, although there is a small thickness deviation from the center of the electrode assembly to the portion within a predetermined distance, the thickness deviation increases as the distance from the center of the electrode assembly increases from the portion at a predetermined distance to the portion at a distance greater than the predetermined distance.

[0004] When the electrode assembly has the thickness deviation described above, if a force is applied to one side of the bag surrounding the electrode assembly, a relatively small force may be applied to the portion of the bag that is far from the center of the electrode assembly and adjacent to the positive and negative electrode tabs.

[0005] Thus, if a relatively small force is applied to the portion of the bag adjacent to the positive and negative electrode tabs, the interface between the positive and negative electrodes and the separator may become uneven, and the electrolyte may be unevenly distributed at the interface between the positive and negative electrodes and the separator.

[0006] As a result, the direction of movement of lithium ions through the electrolyte will deviate. If the lithium ions deviate and move towards the negative electrode, the lithium ions that cannot move into the negative electrode from the part where a large number of lithium ions are gathered in the negative electrode will be deposited on the surface of the negative electrode in the form of lithium metal.

[0007] On the other hand, when the temperature of the battery cell increases, the resistance of the predetermined part of the positive or negative electrode may decrease, causing the movement of lithium ions to deviate from the direction, and thus lithium ions will be deposited on the surface of the negative electrode in the form of lithium metal.

[0008] If lithium metal is deposited on the surface of the negative electrode, the cell capacity may be reduced and the lifespan may be shortened.

[0009] Moreover, the following problems exist: lithium deposited in metallic form may electrically connect the positive and negative electrodes, causing an internal short circuit, which may cause the battery cell to catch fire.

[0010] Therefore, there is a need to develop a battery cell and a battery assembly including the battery cell, wherein one side of the cell can be subjected to a uniform force and effectively dissipate heat, and the amount of lithium metal deposited at the negative electrode can be reduced. Summary of the Invention

[0011] Technical issues

[0012] One object of this disclosure is to provide a battery cell that can reduce the amount of lithium metal deposited at the negative electrode.

[0013] Another object of this disclosure is to provide a battery assembly including a cell that can reduce the amount of lithium metal deposited at the negative electrode.

[0014] The battery cell and battery assembly including the battery cell disclosed herein can be widely used in green technology fields such as electric vehicles. Furthermore, the battery cell and battery assembly including the battery cell disclosed herein can be used in environmentally friendly electric vehicles, hybrid vehicles, and the like to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0015] Technical solution

[0016] As a technical solution to solve the above-mentioned technical problems, a battery cell according to an embodiment of the present disclosure includes: an electrode assembly formed by alternatingly stacking a plurality of positive electrodes and a plurality of negative electrodes with separators spaced apart along a predetermined direction; a positive electrode tab electrically connected to the plurality of positive electrodes at one end in a length direction perpendicular to the predetermined direction of the electrode assembly; a negative electrode tab electrically connected to the plurality of negative electrodes at the other end in the length direction of the electrode assembly; a bag housing the electrode assembly inside, such that at least a portion of the positive electrode tab and at least a portion of the negative electrode tab are exposed to the outside; and a pressure pad attached to one side of the bag perpendicular to the predetermined direction, the thickness of the pressure pad being variable according to the distance between it and the positive electrode tab and the distance between it and the negative electrode tab, the thickness being the length in a direction perpendicular to one side of the bag.

[0017] Furthermore, in the pressure pad, the thickness of the first portion adjacent to the positive electrode tab is the first thickness, the thickness of the second portion adjacent to the negative electrode tab is the second thickness, and the thickness of the third portion other than the first and second portions is the third thickness. The first and second thicknesses may be thicker than the third thickness.

[0018] Furthermore, the positive electrode tab is located at one end of the length direction of the surface, the negative electrode tab is located at the other end of the length direction of the surface, the pressure pad extends along the length direction and can be formed to cover the area between one end of the length direction of the surface and the other end of the length direction of the surface.

[0019] Furthermore, the first portion may be disposed between one end of the pressure pad in the length direction and a position spaced apart by a first length from one end of the pressure pad in the length direction toward the other end of the pressure pad in the length direction, and the second portion may be disposed between the other end of the pressure pad in the length direction and a position spaced apart by a second length from the other end of the pressure pad in the length direction toward one end of the pressure pad in the length direction.

[0020] Furthermore, the thickness of the first part, the thickness of the second part, and the thickness of the third part can be formed at a constant value.

[0021] Furthermore, the first part may include a first cooling component for absorbing heat released from said side, and the second part may include a second cooling component for absorbing heat released from said side.

[0022] Furthermore, the thickness of the first cooling component is constant, and the first cooling component is disposed in the first portion and opposite to the surface. The thickness of the second cooling component is constant, and the second cooling component can be disposed in the second portion and opposite to the surface.

[0023] Furthermore, the first cooling component can be disposed in the first part at the maximum distance between the first cooling component and the surface, and the second cooling component can be disposed in the second part at the maximum distance between the second cooling component and the surface.

[0024] Furthermore, the pressure pad may contain rubber, and the first cooling component and the second cooling component may contain paraffin wax.

[0025] Furthermore, the first thickness of the first portion and the second thickness of the second portion may be the same, and the first length of the first portion and the second length of the second portion may be the same.

[0026] Furthermore, the first thickness and the second thickness can be more than 1.5 times and less than 3 times the third thickness, and the first length and the second length can be more than 0.25 times and less than 0.375 times the length of the pressure pad in the length direction.

[0027] As a technical solution to solve the above-mentioned technical problems, a battery assembly according to an embodiment of the present disclosure includes: a housing having an internal receiving space; and a cell assembly housed in the receiving space, which is formed by stacking a plurality of cells, wherein the cells can be cells according to an embodiment of the present disclosure.

[0028] Furthermore, the first thickness of the first portion of the battery cell can be the same as the second thickness of the second portion, and the first length of the first portion can be the same as the second length of the second portion.

[0029] Furthermore, the first thickness and the second thickness can be more than 1.5 times and less than 3 times the third thickness, and the first length and the second length can be more than 0.25 times and less than 0.375 times the distance between the positive electrode tab and the negative electrode tab.

[0030] Specific details of other embodiments for solving this technical problem are included in the specification and drawings of this invention.

[0031] Technical effect

[0032] According to the solution to the technical problem of the present disclosure as described above, in the battery cell and battery assembly including the battery cell of the present disclosure, a uniform force can be applied to one side of the cell, thereby providing the effect of reducing the amount of lithium metal deposited at the negative electrode of the battery cell.

[0033] Furthermore, the pocket side of the battery cell can effectively dissipate heat, thereby reducing the amount of lithium metal deposited at the negative electrode of the battery cell. Attached Figure Description

[0034] Figure 1 A cross-sectional view of a battery cell according to an embodiment of the present disclosure is shown.

[0035] Figure 2 This is a 3D diagram of the battery cell.

[0036] Figure 3 This is a 3D view of the pressure pad.

[0037] Figure 4 The figure shows an example of a pressure pad including a cooling component.

[0038] Figure 5 The figure shows another example of a pressure pad including a cooling component.

[0039] Figure 6 This is a side view of the pressure pad.

[0040] Figure 7 A graph showing the capacity retention and expansion rate of the cell based on the thickness of each part of the pressure pad.

[0041] Figure 8 A graph showing the capacity retention and expansion rate of the cell based on the length of each part of the pressure pad.

[0042] Figure 9This is an exploded perspective view of a battery assembly according to an embodiment of the present disclosure.

[0043] Explanation of reference numerals in the attached figures

[0044] 1: Battery Cell

[0045] 2: Battery Components

[0046] 10: Shell

[0047] 20: Battery cell assembly

[0048] 30: Busbar Component

[0049] 100: Electrode assembly

[0050] 200: Positive electrode tab

[0051] 300: Negative electrode tab

[0052] 400: bag

[0053] 500: Pressure Pad

[0054] 510: Part One

[0055] 512: First cooling component

[0056] 520: Part Two

[0057] 522: Second cooling component

[0058] 530: Part Three Detailed Implementation

[0059] The embodiments of this application will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily implement it. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Moreover, in order to clearly illustrate this application, parts unrelated to the description have been omitted in the drawings, and similar reference numerals have been given to similar parts throughout the specification.

[0060] Throughout this application, when referring to a part being "connected" to another part, this includes not only the case of a "direct connection" but also the case of an "electrical connection" between the two parts separated by other devices.

[0061] Throughout this application, when it is mentioned that a component is "on" another component, this includes not only the case where the component is in contact with the other component, but also the case where there are other components between them.

[0062] Throughout this application, when a part is referred to as "including" a component, it means that other components may also be included, but does not exclude other components, unless specifically stated to the contrary. The degree terms "about," "substantially," etc., used throughout this application, when inherent manufacturing and material tolerances exist in their meaning, are used to indicate the meaning of the numerical value or approximate numerical value, and are used to prevent unscrupulous infringers from improperly using the disclosure of precise or absolute values ​​mentioned for ease of understanding. The phrases "performing the step of..." or "the step of..." used throughout this application do not mean "the step for...".

[0063] The preferred embodiments of this disclosure will now be described in detail with reference to the accompanying drawings and the following description. However, this disclosure is not limited to the embodiments described herein, but may take other forms. Throughout this specification, the same reference numerals denote the same components.

[0064] The following describes a battery cell according to an embodiment of the present disclosure.

[0065] Figure 1 A cross-sectional view of a battery cell according to an embodiment of the present disclosure is shown.

[0066] Reference Figure 1 In general, the battery cell 1 includes an electrode assembly 100, a positive electrode tab 200, a negative electrode tab 300, a bag 400, and a pressure pad 500.

[0067] First, let’s describe the electrode assembly 100.

[0068] like Figure 1 As shown, the electrode assembly 100 can be formed by alternatingly stacking multiple positive electrodes 110 and multiple negative electrodes 120 with a separator 130 between them along a predetermined direction.

[0069] The positive electrode 110 can be formed by coating a positive electrode active material such as a transition metal oxide onto a positive electrode current collector formed of a metal foil such as aluminum.

[0070] Furthermore, the positive electrode 110 includes an uncoated portion of the positive electrode, which is a region where the positive electrode active material is not coated, and the uncoated portion of the positive electrode can serve as a pathway for current flow between the positive electrode 110 and the outside.

[0071] The negative electrode 120 can be formed by coating a negative electrode active material such as graphite or carbon onto a negative electrode current collector made of a metal foil such as copper or nickel.

[0072] Furthermore, the negative electrode 120 includes an uncoated portion of the negative electrode, which is a region where the negative electrode active material is not coated, and the uncoated portion of the negative electrode can serve as a pathway for current flow between the negative electrode 120 and the outside.

[0073] The separator 130 is located between the positive electrode 110 and the negative electrode 120, and serves to prevent short circuits and allow lithium ions to move. This separator can be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.

[0074] An electrode assembly 100 is formed by alternately stacking multiple positive electrodes 110 and multiple negative electrodes 120, spaced apart by a separator 130, in the manner described above. Figure 1 As shown, the electrode assembly 100 can be housed inside the bag 400.

[0075] Next, the positive electrode tab 200 will be explained.

[0076] like Figure 1 As shown, the positive electrode tab 200 can be electrically connected to a plurality of positive electrodes 110 at one end in the length direction (hereinafter referred to as the length direction) perpendicular to the predetermined direction of the electrode assembly 100.

[0077] Specifically, the positive electrode tab 200 can be electrically connected to the positive electrode 110 by connecting a conductive component to a plurality of uncoated positive electrode portions, or it can be formed by a plurality of uncoated positive electrode portions.

[0078] Next, the negative electrode tab 300 will be explained.

[0079] like Figure 1 As shown, the negative electrode tab 300 can be electrically connected to a plurality of negative electrodes 120 at the other end of the electrode assembly 100 along its length.

[0080] Specifically, the negative electrode tab 300 can be electrically connected to the negative electrode 120 by connecting a conductive component to a plurality of uncoated negative electrode portions, or it can be formed by a plurality of uncoated negative electrode portions.

[0081] Next, we will explain bag 400.

[0082] like Figure 1 As shown, the bag 400 internally houses the electrode assembly 100, allowing at least a portion of the positive electrode tab 200 and at least a portion of the negative electrode tab 300 to be exposed externally.

[0083] In this case, the positive electrode tab 200 can be positioned adjacent to one end of the length direction of one side of the bag 400, and the negative electrode tab 300 can be positioned adjacent to the other end of the length direction of one side of the bag 400.

[0084] This bag 400 can be formed from a soft insulating material, but the composition of the bag 400 is not limited to this.

[0085] Next, the pressure pad 500 will be explained.

[0086] Figure 2This is a 3D diagram of the battery cell.

[0087] Reference Figure 1 and Figure 2 In other words, the pressure pad 500 can be attached to one side of the bag 400 perpendicular to the predetermined direction.

[0088] Specifically, the pressure pad 500 can be formed extending in the length direction and bonded to one side of the bag 400 in such a way that it covers one end of the bag 400 in the length direction and the other end of the bag 400 in the length direction.

[0089] For example, the pressure pad 500 can be formed to completely cover one side of the bag 400 and bonded to one side of the bag 400, and may include rubber, but the composition of the pressure pad 500 is not limited to this.

[0090] When multiple cells 1 are configured to press one side of the bag 400 against each other, the pressure pad 500 can apply a force of uniform magnitude to one side of the bag 400, and can be formed such that the thickness (hereinafter referred to as the thickness) is a length in a direction perpendicular to one side of the bag 400 and varies depending on the distance between the positive electrode tab 200 and the negative electrode tab 300.

[0091] Figure 3 This is a 3D view of the pressure pad.

[0092] For example, refer to Figure 3 In general, the pressure pad 500 may include a first portion 510 adjacent to the positive electrode tab 200, a second portion 520 adjacent to the negative electrode tab 300, and a third portion 530 which is a portion other than the first portion 510 and the second portion 520.

[0093] In this case, the pressure pad 500 can be configured such that the first part 510, the second part 520 and the third part 530 are integrally formed, or it can be configured such that the first part 510 and the second part 520 are formed by pre-defined components joined to one side of the length direction and the other side of the length direction of the third part 530 extending along the length direction.

[0094] Furthermore, the first thickness T1, which is the thickness of the first part 510, and the second thickness T2, which is the thickness of the second part 520, can be made to be thicker than the third thickness T3, which is the thickness of the third part 530.

[0095] As described above, if the first portion 510 and the second portion 520 of the pressure pad 500 are formed to be thicker than the third portion 530, a uniform force can be applied to each position on one side of the bag 400 of the electrode assembly 100, which is thinner than the center portion surrounding the portion adjacent to the positive electrode tab 200 and the negative electrode tab 300.

[0096] In this case, the thickness of each of the first part 510, the second part 520 and the third part 530 can be formed constant.

[0097] On the other hand, the pressure pad 500 can be configured to effectively dissipate the heat generated from the cell 1.

[0098] Figure 4 The figure shows an example of a pressure pad including a cooling component.

[0099] Specifically, refer to Figure 4 In other words, the first portion 510 of the pressure pad 500 may include a first cooling component 512 for absorbing heat released from one side of the bag 400, and the second portion 520 may include a second cooling component 522 for absorbing heat released from one side of the bag 400.

[0100] The first cooling component 512 and the second cooling component 522 can be formed from substances with relatively high latent heat and chemical stability.

[0101] For example, the first cooling component 512 and the second cooling component 522 may be formed from paraffin wax. When the first cooling component 512 and the second cooling component 522 are formed from paraffin wax, they can be easily attached to the pressure pad 500 formed from rubber, and the first cooling component 512 and the second cooling component 522 can be manufactured at a relatively low cost.

[0102] The first cooling component 512 and the second cooling component 522 can be respectively arranged in the first part 510 and the second part 520 in various structures.

[0103] For example, such as Figure 4 As shown, the thickness of the first cooling component 512 is constant, and the first cooling component 512 can be disposed in the first part 510 and opposite one side of the bag 400. The thickness of the second cooling component 522 is constant, and the second cooling component 522 can be disposed in the second part 520 and opposite one side of the bag 400.

[0104] Figure 5 The figure shows another example of a pressure pad including a cooling component.

[0105] To give another example, such as Figure 5 As shown, the first cooling component 512 can be disposed in the first part 510 with the distance between the first cooling component 512 and one side of the bag 400 being the greatest, and the second cooling component 522 can be disposed in the second part 520 with the distance between the second cooling component 522 and one side of the bag 400 being the greatest.

[0106] That is, the first cooling component 512 may be located on the surface of the first part 510, and the second cooling component 522 may be located on the surface of the second part 520.

[0107] As described above, by including a first cooling component 512 in the first part 510 and a second cooling component 522 in the second part 520, the portions of the cell 1 adjacent to the positive electrode tab 200 and the negative electrode tab 300 effectively dissipate heat, and the temperature of the portions of the positive electrode 110 and the negative electrode 120 adjacent to the positive electrode tab 200 and the negative electrode tab 300 increases, and the resistance decreases, thereby preventing the movement of lithium ions from deviating from the direction.

[0108] Therefore, lithium ions can be prevented from accumulating in a predetermined portion of the negative electrode 120, and the amount of lithium ions that fail to move into the interior of the negative electrode 120 can be effectively reduced by depositing in metallic form on the surface of the negative electrode 120.

[0109] On the other hand, the first part 510 and the second part 520 of the pressure pad 500 can be formed to more effectively prevent the performance degradation of the cell 1 and to more effectively prevent the cell 1 from expanding.

[0110] Figure 6 This is a side view of the pressure pad.

[0111] Specifically, such as Figure 6 As shown, the first portion 510 may be disposed between one end of the pressure pad 500 in the length direction and a position separated by a first length L1 from one end of the pressure pad 500 in the length direction along the direction toward the other end of the pressure pad 500 in the length direction.

[0112] Furthermore, the second portion 520 may be disposed between the other end of the pressure pad 500 in the length direction and a position separated by a second length L2 from the other end of the pressure pad 500 in the length direction along one end of the pressure pad 500 in the length direction.

[0113] In this case, the first thickness T1 of the first part 510 and the second thickness T2 of the second part 520 can be the same, and the first length L1 of the first part 510 and the second length L2 of the second part 520 can be the same.

[0114] Furthermore, the first thickness T1 of the first part 510 and the second thickness T2 of the second part 520 can be more than 1.5 times and less than 3 times the third thickness T3 of the third part 530, and the first length L1 of the first part 510 and the second length L2 of the second part 520 can be more than 0.25 times and less than 0.375 times the length L in the length direction of the pressure pad 500.

[0115] As described above, by forming the first portion 510 and the second portion 520, the performance degradation of the cell 1 with the pressure pad 500 is prevented, and expansion is prevented.

[0116] Figure 7 A graph showing the capacity retention and expansion rate of the cell based on the thickness of each part of the pressure pad.

[0117] Specifically, refer to Figure 7 In other words, Figure 7 In the graph, the solid line represents the capacity retention rate (%) of the cell based on the thickness of the first portion 510 and the second portion 520 of the pressure pad 500, and the dashed line represents the expansion rate (%) of the cell based on the thickness of the first portion 510 and the second portion 520 of the pressure pad 500.

[0118] Furthermore, Figure ① is the figure when the thickness of the first part 510, the thickness of the second part 520, and the thickness of the third part 530 are the same; Figure ② is the figure when the thickness of the first part 510 and the thickness of the second part 520 are 1.2 times the thickness of the third part 530; Figure ③ is the figure when the thickness of the first part 510 and the thickness of the second part 520 are 1.5 times the thickness of the third part 530; Figure ④ is the figure when the thickness of the first part 510 and the thickness of the second part 520 are 3 times the thickness of the third part 530; and Figure ⑤ is the figure when the thickness of the first part 510 and the thickness of the second part 520 are 3.5 times the thickness of the third part 530.

[0119] like Figure 7 As shown, compared to the case where the thickness of the first part 510 and the thickness of the second part 520 are 1.2 or 3.5 times the thickness of the third part 530 when the pressure pad 500 is combined with the cell 1, the reduction rate of the cell capacity retention rate (%) is smaller when the pressure pad 500 with the thickness of the first part 510 and the thickness of the second part 520 are 1.5 or 3 times the thickness of the third part 530 is combined with the cell 1 as charging and discharging are repeated.

[0120] Moreover, such as Figure 7 As shown, compared to the case where the thickness of the first part 510 and the thickness of the second part 520 are 1.2 or 3.5 times the thickness of the third part 530 when the pressure pad 500 is combined with the cell 1, the increase rate of cell expansion (%) is smaller when the thickness of the first part 510 and the thickness of the second part 520 are 1.5 or 3 times the thickness of the third part 530 when the pressure pad 500 is combined with the cell 1 as charging and discharging are repeated.

[0121] In other words, when the thickness of the first part 510 and the thickness of the second part 520 are more than 1.5 times and less than 3 times the thickness of the third part 530, the pressure pad 500 is combined with the battery cell 1. It can be seen that even if the battery cell 1 is repeatedly charged and discharged, the decrease in the capacity retention rate (%) of the battery cell 1 is small, and the increase in the expansion rate (%) of the battery cell 1 is small. Therefore, the performance degradation of the battery cell 1 can be effectively prevented.

[0122] Figure 8 A graph showing the capacity retention and expansion rate of the cell based on the length of each part of the pressure pad.

[0123] Moreover, refer to Figure 8 In other words, Figure 8 In the graph, the solid line represents the capacity retention rate (%) of the cell based on the length of the first portion 510 and the second portion 520 of the pressure pad 500, and the dashed line represents the expansion rate (%) of the cell based on the length of the first portion 510 and the second portion 520 of the pressure pad 500.

[0124] Furthermore, Figure ① is the figure when the length of the first part 510 and the length of the second part 520 are 0; Figure ② is the figure when the length of the first part 510 and the length of the second part 520 are 0.125 times the length of the pressure pad 500; Figure ③ is the figure when the length of the first part 510 and the length of the second part 520 are 0.25 times the length of the pressure pad 500; Figure ④ is the figure when the length of the first part 510 and the length of the second part 520 are 0.375 times the length of the pressure pad 500; and Figure ⑤ is the figure when the length of the first part 510 and the length of the second part 520 are 0.5 times the length of the pressure pad 500.

[0125] like Figure 8 As shown, compared to the case where the length of the first part 510 and the length of the second part 520 are 0.125 times or 0.5 times the length of the pressure pad 500 combined with the cell 1, the reduction rate of the cell capacity retention rate (%) is smaller when the length of the first part 510 and the length of the second part 520 are 0.25 times or 0.375 times the length of the pressure pad 500 combined with the cell 1 as charging and discharging are repeated.

[0126] Moreover, such as Figure 8As shown, compared to the case where the length of the first part 510 and the length of the second part 520 are 0.125 times or 0.5 times the length of the pressure pad 500 combined with the cell 1, the increase rate of cell expansion rate (%) is smaller when the length of the first part 510 and the length of the second part 520 are 0.25 times or 0.375 times the length of the pressure pad 500 combined with the cell 1 as charging and discharging are repeated.

[0127] In other words, when the length of the first part 510 and the length of the second part 520 are more than 0.25 times and less than 0.375 times the length of the pressure pad 500 when the pressure pad 500 is combined with the battery cell 1, it can be seen that even if the battery cell 1 is repeatedly charged and discharged, the decrease in the capacity retention rate (%) of the battery cell 1 is small, and the increase in the expansion rate (%) of the battery cell 1 is small. Therefore, the performance degradation of the battery cell 1 can be effectively prevented.

[0128] The following describes a battery assembly according to an embodiment of the present disclosure.

[0129] Figure 9 This is an exploded perspective view of a battery assembly according to an embodiment of the present disclosure.

[0130] Reference Figure 9 In general, the battery assembly 2 may include a housing 10, a cell assembly 20, and a busbar assembly 30.

[0131] First, let’s describe the housing 10.

[0132] The housing 10 can form an internal accommodating space.

[0133] Specifically, the housing 10 can form the appearance of the battery assembly 2, such as Figure 9 As shown, it may include: a lower plate 11; a side plate 12 connected to the lower plate 11 to form a receiving space; and an upper plate 13 attached to the side plate 12 in a manner that seals the receiving space.

[0134] Next, the battery cell assembly 20 will be described.

[0135] The cell assembly 20 is housed in the housing space and can be formed by stacking multiple cells 1.

[0136] The battery cell 1 included in the battery cell assembly 20 is the same as the battery cell 1 according to an embodiment of the present disclosure, and therefore a detailed description will be omitted below.

[0137] On the other hand, the multiple cells 1 included in the cell assembly 20 can be stacked in such a way that the cells 1 adjacent to one side of the bag 400 to which the pressure pad 500 is attached are opposite each other.

[0138] Therefore, each cell 1 included in the cell assembly 20 can be pressurized by the pressure pad 500 adjacent to the cell 1, and a uniform force can be applied to each position on one side of the bag 400 surrounding the electrode assembly 100.

[0139] Next, the busbar assembly 30 will be described in detail.

[0140] Reference Figure 9 In general, the busbar assembly 30 may include: at least one busbar configured to electrically connect a plurality of cells 1 to each other; and a busbar frame configured to mount the busbar on the outside.

[0141] This busbar assembly 30 can be disposed in the receiving space and electrically connected to multiple battery cells 1. For example, the busbar assembly 30 can be disposed and housed in the receiving space with the battery cell assemblies 20 in between, so as to electrically connect to multiple stacked battery cells 1.

[0142] As described above, according to the solution to the technical problem of the present disclosure, in the battery cell and battery assembly including the battery cell, a uniform force can be applied to one side of the cell, thereby providing the effect of reducing the amount of lithium metal deposited at the negative electrode of the battery cell.

[0143] Furthermore, the pocket side of the battery cell can effectively dissipate heat, thereby reducing the amount of lithium metal deposited at the negative electrode of the battery cell.

[0144] The foregoing descriptions of this disclosure are merely exemplary. Those skilled in the art will understand that variations can be readily made in other specific forms without altering the technical concept or essential features of this disclosure. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, components described as a single entity can be implemented separately; similarly, components described as distributed can be implemented in combination.

[0145] The scope of this disclosure is defined by the appended claims, not by the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents shall be construed as being included within the scope of this disclosure.

Claims

1. A battery cell, comprising: An electrode assembly is formed by alternating layers of multiple positive electrodes and multiple negative electrodes separated by membranes along a predetermined direction; The positive electrode tab is electrically connected to the plurality of positive electrodes at one end along its length direction perpendicular to the predetermined direction of the electrode assembly; The negative electrode tab is electrically connected to the plurality of negative electrodes at the other end of the electrode assembly along the length direction. A bag that houses the electrode assembly inside, such that at least a portion of the positive electrode tab and at least a portion of the negative electrode tab are exposed to the outside; as well as A pressure pad is attached to one side of the bag, perpendicular to the predetermined direction. The thickness of the pressure pad varies depending on the distance between it and the positive electrode tab and the negative electrode tab, and the thickness is the length in the direction perpendicular to one side of the bag.

2. The battery cell according to claim 1, wherein: In the pressure pad, the thickness of the first portion adjacent to the positive electrode tab is the first thickness, the thickness of the second portion adjacent to the negative electrode tab is the second thickness, and the thickness of the third portion other than the first and second portions is the third thickness. The first and second thicknesses are thicker than the third thickness.

3. The battery cell according to claim 2, wherein: The positive electrode tab is positioned adjacent to one end of the bag along its length. The negative electrode tab is positioned adjacent to the other end of one side of the bag along its length. The pressure pad extends along the length direction and is formed between one end of the length direction covering one side of the bag and the other end of the length direction covering one side of the bag.

4. The battery cell according to claim 3, wherein: The first portion is disposed between one end of the pressure pad along its length and a position spaced a first length apart from one end of the pressure pad along its length toward the other end of the pressure pad. The second portion is disposed between the other end of the pressure pad in the length direction and a position spaced a second length apart from the other end of the pressure pad in the length direction along a direction toward one end of the pressure pad in the length direction.

5. The battery cell according to claim 4, wherein: The first thickness of the first part, the second thickness of the second part, and the third thickness of the third part are each formed at a constant thickness.

6. The battery cell according to claim 5, wherein: The first part includes a first cooling component for absorbing heat released from said side of the bag. The second part includes a second cooling component for absorbing heat released from one side of the bag.

7. The battery cell according to claim 6, wherein: The first cooling component is formed with a constant thickness, and is disposed in the first portion and opposite to one side of the bag. The second cooling component is formed to have a constant thickness and is disposed in the second portion and opposite to one side of the bag.

8. The battery cell according to claim 7, wherein: The first cooling component is positioned in the first portion such that the distance between the first cooling component and one side of the bag is maximized. The second cooling component is disposed in the second part such that the distance between the second cooling component and the said side of the bag is maximized.

9. The battery cell according to claim 8, wherein: The pressure pad contains rubber. The first cooling component and the second cooling component each contain paraffin wax.

10. The battery cell according to any one of claims 5 to 9, wherein, The first thickness of the first portion is the same as the second thickness of the second portion. The first length of the first part is the same as the second length of the second part.

11. The battery cell according to claim 10, wherein: The first thickness and the second thickness are more than 1.5 times and less than 3 times the third thickness. The first length and the second length are more than 0.25 times and less than 0.375 times the length of the pressure pad in the length direction.

12. A battery assembly, comprising: The shell has an internal space for receptacle; as well as The battery cell assembly, housed in the receiving space, is composed of multiple battery cells stacked together. The battery cell is the battery cell according to any one of claims 1 to 9.

13. The battery assembly according to claim 12, wherein: The first thickness of the first portion of the battery cell is the same as the second thickness of the second portion. The first length of the first portion of the battery cell is the same as the second length of the second portion.

14. The battery assembly of claim 13, wherein: The first thickness and the second thickness are more than 1.5 times and less than 3 times the third thickness. The first length and the second length are more than 0.25 times and less than 0.375 times the distance between the positive electrode tab and the negative electrode tab.

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