Battery

Abstract

The battery comprises a battery cell and a liquid storage part, the liquid storage part is arranged on the surface of the battery cell and is configured to store part of electrolyte of the battery, the liquid storage capacity value of the liquid storage part is between a first threshold value and a second threshold value, and the ratio of the second threshold value to the first threshold value is larger than or equal to 1 and smaller than or equal to 3.75. The electrolyte retention capacity of the battery can be improved on the premise that the energy density of the battery is not reduced, the battery can be fed back to the battery cell in the middle and later periods of long circulation, the cycle performance of the battery is improved, and performance deterioration caused by the fact that residual electrolyte in the shell of the battery is enriched at the bottom is avoided.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to a battery. Background Art

[0002] Lithium-ion batteries have high energy density, power density, and long cycle life, and play an important role in fields such as wind energy, solar power generation energy storage systems, and new energy vehicles. During long cycles, lithium-ion batteries consume a large amount of electrolyte, so it is necessary for lithium-ion batteries to have a high liquid retention capacity to avoid a decrease in cycle performance in the later stage of long cycles.

[0003] In related technologies, usually, the compaction of the positive and negative electrodes of the battery is reduced, or the thickness of the separator is increased, or the injection volume is increased, etc., to improve the liquid retention capacity of the lithium-ion battery. However, reducing the compaction of the positive and negative electrodes of the lithium-ion battery or increasing the thickness of the separator will reduce the energy density of the battery. At the same time, after increasing the injection volume, most of the injected electrolyte accumulates at the bottom of the battery case, making it difficult to distribute evenly and causing many side reactions in the electrolyte enrichment area at high temperatures, which may induce problems such as lithium deposition and deteriorate the cycle performance.

[0004] Therefore, how to avoid a decrease in the cycle performance of the battery in the later stage of long cycles on the premise of not reducing the energy density of the battery and avoiding excessive accumulation of electrolyte at the bottom of the battery case is a technical problem that needs to be solved urgently at present. Summary of the Invention

[0005] In view of the deficiencies of the prior art, this application provides a battery that can avoid a decrease in the cycle performance of the battery in the later stage of long cycles on the premise of not reducing the energy density of the battery and avoiding excessive accumulation of electrolyte at the bottom of the battery case.

[0006] This application provides a battery, which includes:

[0007] An electrode assembly;

[0008] A liquid storage member disposed on the surface of the electrode assembly;

[0009] Wherein, the liquid storage member is configured to store part of the electrolyte of the battery, the liquid storage capacity value of the liquid storage member is greater than or equal to a preset first threshold and less than or equal to a preset second threshold; the ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75; the liquid storage capacity value is configured to represent the liquid storage amount of the electrolyte stored by the liquid storage member per unit gram weight.

[0010] Further, in the battery provided by this application, the first threshold is greater than 0 and less than or equal to 8 g / g; the second threshold is greater than or equal to 8 g / g and less than or equal to 30 g / g.

[0011] Further, in the battery provided by this application, the liquid storage capacity value satisfies: Wherein, P is the liquid storage capacity value in g / g, α is the oil absorption value of the liquid storage member in g / cm 3 , β is the porosity of the liquid storage member in %, V is the volume of the liquid storage member in cm 3 , and m is the mass of the liquid storage member in g.

[0012] Furthermore, in the battery provided by the present application, the first contact angle of the liquid storage member with respect to the electrolyte is higher than the second contact angle of the battery's electrode sheet with respect to the electrolyte and / or the third contact angle of the battery's separator with respect to the electrolyte.

[0013] Even further, in the battery provided by the present application, the first contact angle is greater than or equal to 25° and less than or equal to 50°.

[0014] Furthermore, in the battery provided by the present application, the battery further includes a top cover configured to encapsulate the battery cell;

[0015] The battery cell includes a first surface, and the liquid storage member includes a first liquid storage portion provided on the first surface and / or a second liquid storage portion provided on the first surface; the first surface is provided on the side of the battery cell facing the top cover.

[0016] Even further, in the battery provided by the present application, a positive electrode tab and a negative electrode tab are further provided on the battery cell, and a positive electrode post and a negative electrode post are provided on the side of the top cover away from the first surface. The positive electrode post is connected to the positive electrode tab, and the negative electrode post is connected to the negative electrode tab.

[0017] Even further, in the battery provided by the present application, the positive electrode tab and the negative electrode tab are both on the same side of the battery cell. The first liquid storage portion is located on the side of the positive electrode tab away from the negative electrode tab, and / or the second liquid storage portion is located on the side of the negative electrode tab away from the positive electrode tab.

[0018] Even further, in the battery provided by the present application, the positive electrode tab and the negative electrode tab are both provided on the first surface.

[0019] Even further, in the battery provided by the present application, the positive electrode tab and the negative electrode tab are respectively on different sides of the battery cell.

[0020] Even further, in the battery provided by the present application, the battery cell further includes a second surface and a third surface, the second surface and the third surface are corresponding surfaces of the battery cell, and the liquid storage member further includes a third liquid storage portion provided on the second surface and / or a fourth liquid storage portion provided on the third surface;

[0021] Wherein, the third liquid storage portion is connected to the first liquid storage portion, and / or the fourth liquid storage portion is connected to the second liquid storage portion.

[0022] Even further, in the battery provided by the present application, the battery cell further includes a fourth surface, and the liquid storage member further includes a fifth liquid storage portion;

[0023] Among them, the fourth surface and the first surface are corresponding surfaces of the battery cell, and both ends of the fifth liquid storage part are respectively connected to the third liquid storage part and the fourth liquid storage part.

[0024] Furthermore, in the battery provided by the present application, the thickness ratio between the first liquid storage part and the third liquid storage part is greater than or equal to 2 and less than or equal to 30; or / and,

[0025] the thickness ratio between the first liquid storage part and the fourth liquid storage part is greater than or equal to 2 and less than or equal to 30; or / and,

[0026] the thickness ratio between the first liquid storage part and the fifth liquid storage part is greater than or equal to 2 and less than or equal to 30; or / and,

[0027] the thickness ratio between the second liquid storage part and the third liquid storage part is greater than or equal to 2 and less than or equal to 30; or / and,

[0028] the thickness ratio between the second liquid storage part and the fourth liquid storage part is greater than or equal to 2 and less than or equal to 30; or / and,

[0029] the thickness ratio between the second liquid storage part and the third liquid storage part is greater than or equal to 2 and less than or equal to 30.

[0030] Furthermore, in the battery provided by the present application, the thickness of the first liquid storage part, or / and the thickness of the second liquid storage part is greater than or equal to 1 mm and less than or equal to 3 mm, and the thickness of the third liquid storage part, or / and the thickness of the fourth liquid storage part, or / and the thickness of the fifth liquid storage part is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

[0031] Furthermore, in the battery provided by the present application, when the liquid storage member includes the first liquid storage part, the second liquid storage part, the third liquid storage part, the fourth liquid storage part and the fifth liquid storage part, the first liquid storage part, the second liquid storage part, the third liquid storage part, the fourth liquid storage part and the fifth liquid storage part are integrally formed to form the liquid storage member.

[0032] Furthermore, in the battery provided by the present application, the positive electrode post is connected to the positive electrode tab by a positive electrode adapter piece, and the negative electrode post is connected to the negative electrode tab by a negative electrode adapter piece.

[0033] Furthermore, in the battery provided by the present application, an explosion-proof valve is further provided on the top cover, and the explosion-proof valve is arranged between the positive electrode post and the negative electrode post.

[0034] Further, in the battery provided by the present application, the battery further includes a housing;

[0035] Among them, the housing is configured to assemble the liquid storage member and the battery cell.

[0036] Further, in the battery provided by the present application, the battery further includes a protective film, and the protective film is configured to wrap the housing to protect the battery cell.

[0037] Further, in the battery provided by the present application, the liquid storage member is at least one of a liquid storage member made of polyethylene fiber, a liquid storage member made of polypropylene fiber, a liquid storage member made of polyester fiber, a liquid storage member made of aramid, a liquid storage member made of polyurethane, a liquid storage member made of polyamide, a liquid storage member made of alkyl vinyl polymer, a liquid storage member made of polylactic acid, and a liquid storage member made of acrylate-styrene copolymer.

[0038] The battery provided by the present application includes a battery cell and a liquid storage member. The liquid storage member is disposed on the surface of the battery cell and is configured to store a part of the electrolyte of the battery. The liquid storage capacity value of the liquid storage member is between a first threshold and a second threshold. The ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75. It can not only improve the liquid retention capacity of the battery without reducing the energy density of the battery, but also facilitate the battery to feedback to the battery cell in the middle and late stages of long cycles, improve the cycle performance of the battery, and avoid the performance deterioration caused by the enrichment of the residual electrolyte inside the housing of the battery at the bottom. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 A schematic structural diagram of a battery provided by the prior art;

[0041] Figure 2 A schematic structural diagram of a battery provided by an embodiment of the present application;

[0042] Figure 3 A front view of a liquid storage member provided by an embodiment of the present application;

[0043] Figure 4 A front view of a battery after assembling a liquid storage member provided by an embodiment of the present application;

[0044] Figure 5 A side view of a battery after assembling a liquid storage member provided by an embodiment of the present application;

[0045] Figure 6 A front view of a battery provided by an embodiment of the present application.

[0046] Reference Signs:

[0047] 100, battery cell; 101, positive electrode tab; 102, negative electrode tab; 103, positive electrode adapter; 104, negative electrode adapter; 20, insulating film; 200, liquid storage member; 201, first liquid storage part; 202, second liquid storage part; 203, third liquid storage part; 204, fourth liquid storage part; 205, fifth liquid storage part; 300, top cover; 301, positive electrode column; 302, negative electrode column; 303, explosion-proof valve; 400, housing; 500, protective film. Detailed implementation manners

[0048] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0049] It should be understood that when used in this specification and the appended claims, the terms "including" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0050] It should also be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification of the present application and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0051] It should be further understood that the term " / and / or" used in the specification of the present application and the appended claims refers to any combination and all possible combinations of one or more of the related listed items, and includes these combinations.

[0052] In addition, in the present application, unless otherwise clearly defined or limited in the embodiments, the terms "installation", "connection", "connection" and "fixation" etc. appearing in the embodiments should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or integrated. It can be understood that it can also be a mechanical connection, an electrical connection, etc.; of course, it can also be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two components, or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific implementation situations.

[0053] Such as Figure 1As shown in the figure, the present application provides a battery, which includes a battery cell 100, an insulating film 20, a housing 400, and a protective film 500. The insulating film 20 can wrap the side surface of the battery cell 100 to play an insulating role, and the insulating film 20 can also be understood as an insulating gasket. After the battery cell 100 is wrapped by the insulating film 20, it can be assembled into the housing 400, and the housing 400 is wrapped with the protective film 500 to protect the battery cell 100.

[0054] However, the battery provided above will consume the battery during long-term cycling. In order to avoid the reduction of the cycling performance of the battery in the later stage of long-term cycling on the premise of not reducing the energy density of the battery and avoiding excessive enrichment of the electrolyte at the bottom of the battery housing 400.

[0055] Therefore, the present application provides a battery, which may include a battery cell 100, a liquid storage member 200, a housing 400, and a protective film 500. The liquid storage member 200 is disposed on the surface of the battery cell 100 and is configured to store a part of the electrolyte of the battery. The liquid storage capacity value of the liquid storage member 200 is between a first threshold and a second threshold, and the ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75. Among them, the present application can be understood as replacing the insulating film 20 Figure 1 with the liquid storage member 200. Furthermore, on the premise of not reducing the energy density of the battery, the liquid retention capacity of the battery can be improved, and it is also convenient for the battery to feedback to the battery cell 100 in the middle and later stages of long-term cycling, improving the cycling performance of the battery and avoiding the performance deterioration caused by the enrichment of the residual electrolyte inside the battery housing 400 at the bottom.

[0056] Please refer to Figure 2 and Figure 6 , Figure 2 which is a schematic structural diagram of the battery provided by the embodiment of the present application; Figure 6 which is a front view of the battery provided by the embodiment of the present application.

[0057] As Figure 2 and Figure 6 shown, the present application provides a battery, which includes:

[0058] A battery cell 100;

[0059] A liquid storage member 200, disposed on the surface of the battery cell 100;

[0060] Among them, the liquid storage member 200 is configured to store a part of the electrolyte of the battery. The liquid storage capacity value of the liquid storage member 200 is greater than or equal to a preset first threshold and less than or equal to a preset second threshold; the ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75; the liquid storage capacity value is configured to represent the liquid storage amount of the electrolyte stored by the liquid storage member 200 per unit gram weight.

[0061] In this embodiment, the liquid storage member 200 can be a lipophilic and insulating liquid storage member resistant to electrolyte, so as to avoid additional chemical reactions in the battery after the liquid storage member 200 is introduced. At the same time, the liquid storage member 200 can be specifically arranged in the redundant space between the battery cell 100 and the battery housing 400. It can also be understood that the original insulating film 20 is replaced with the liquid storage member 200. The insulating film 20 does not have the liquid storage capacity, and the liquid storage capacity value of the insulating film 20 can be understood as 0. And this application provides to replace the original insulating film 20 with the liquid storage member 200 having the liquid storage capacity, so as to improve the cycling performance of the battery in the middle and later stages without reducing the energy density of the battery. Among them, the liquid storage member 200 can be understood as a component similar to a sponge structure, that is, the liquid storage member 200 with a sponge structure.

[0062] Specifically, the material of the liquid storage member 200 can include at least one of polyethylene fiber, polypropylene fiber, polyester fiber, aramid, polyurethane, polyamide, alkyl vinyl polymer, polylactic acid, acrylate-styrene copolymer.

[0063] Furthermore, the liquid storage member 200 is at least one of the liquid storage member 200 made of polyethylene fiber, the liquid storage member 200 made of polypropylene fiber, the liquid storage member 200 made of polyester fiber, the liquid storage member 200 made of aramid, the liquid storage member 200 made of polyurethane, the liquid storage member 200 made of polyamide, the liquid storage member 200 made of alkyl vinyl polymer, the liquid storage member 200 made of polylactic acid, and the liquid storage member 200 made of acrylate-styrene copolymer.

[0064] By testing the liquid storage capacity value of the liquid storage member 200, it can be determined that the liquid storage capacity value of the liquid storage member 200 is greater than or equal to a preset first threshold and less than or equal to a preset second threshold; the ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75. Among them, the first threshold can be understood as the minimum liquid storage capacity value of the liquid storage member 200, and the second threshold can be understood as the maximum liquid storage capacity value of the liquid storage member 200. Among them, the units of the liquid storage capacity value, the first threshold, and the second threshold can be g / g.

[0065] Exemplarily, the ratio between the second threshold and the first threshold can be 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 3, 3.5, 3.75, etc.

[0066] The battery provided by the present application includes a battery cell 100 and a liquid storage member 200. The liquid storage member 200 is disposed on the surface of the battery cell 100 and is configured to store a part of the electrolyte of the battery. The liquid storage capacity value of the liquid storage member 200 is between a first threshold and a second threshold, and the ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75. It can not only improve the liquid retention capacity of the battery without reducing the energy density of the battery, but also facilitate the battery to feedback to the battery cell 100 in the middle and late stages of long-term cycling, improve the cycling performance of the battery, and avoid the performance deterioration caused by the enrichment of the residual electrolyte inside the battery case 400 at the bottom.

[0067] Further, in some embodiments, the first threshold is greater than 0 and less than or equal to 8 g / g; the second threshold is greater than or equal to 8 g / g and less than or equal to 30 g / g.

[0068] In this embodiment, the minimum liquid storage capacity value of the liquid storage member 200 can be greater than 0 and less than or equal to 8 g / g, and the maximum liquid storage capacity value of the liquid storage member 200 can be greater than or equal to 8 g / g and less than or equal to 30 g / g.

[0069] Specifically, the liquid storage capacity value of the liquid storage member 200 can be between 8 g / g and 30 g / g, the first threshold can be 8 g / g, and the second threshold can be 30 g / g. It can not only ensure that the cycling ability of the battery does not change in the middle and late stages, but also avoid the performance decline and high cost of the battery caused by excessive electrolyte filling in the early stage of the battery.

[0070] In some embodiments, the liquid storage capacity value satisfies: where P is the liquid storage capacity value, α is the oil absorption value of the liquid storage member 200, β is the porosity of the liquid storage member 200, V is the volume of the liquid storage member 200, and m is the mass of the liquid storage member 200.

[0071] In this embodiment, the liquid storage capacity value is configured to characterize the liquid storage amount of the electrolyte stored by the liquid storage member 200 per unit gram weight. It is characterized by the oil absorption value, porosity, volume and weight of the liquid storage member 200, so as to configure the battery more precisely. Thus, it can improve the liquid retention capacity of the battery without reducing the energy density of the battery, and it is also convenient for the battery to feedback to the battery cell 100 in the middle and late stages of long-term cycling, improve the cycling performance of the battery, and avoid the performance deterioration caused by the enrichment of the residual electrolyte inside the battery case 400 at the bottom. Among them, the volume of the liquid storage member 200 can be calculated from the length, width and thickness of the liquid storage member. The unit of the liquid storage capacity value can be g / g, the unit of the oil absorption value can be g / cm 3 , the unit of the volume of the liquid storage member 200 can be cm 3 , and the unit of the mass of the liquid storage member 200 can be g.

[0072] Among them, the oil absorption value refers to the ability of the liquid storage member 200 to absorb the electrolyte, which can be characterized by the volume of the electrolyte absorbed by the liquid storage member 200 per unit mass. There are various methods for measuring the oil absorption value, such as the Piran method, the uniform absorption method, and the static method. In some cases, the oil absorption value can also be measured by an oil absorption value tester, which can determine the oil absorption amount of the sample by detecting the torque change. The porosity is the percentage of the pore volume in the total volume of the material and is an important parameter for measuring the compactness of the liquid storage member 200; the porosity is the percentage of the internal pore volume in the total volume of the material.

[0073] In some embodiments, the first contact angle of the liquid storage member 200 with respect to the electrolyte is higher than the second contact angle of the battery electrode plate with respect to the electrolyte and / or the third contact angle of the battery separator with respect to the electrolyte.

[0074] Specifically, the contact angle is the angle between the tangent of the liquid-gas interface shape at the three-phase contact point and the solid surface when the liquid intersects with the solid surface. The contact angle can reflect the wettability of the liquid on the solid surface, that is, the degree of spreading of the liquid on the solid surface. The smaller the contact angle, the better the wettability of the liquid on the solid surface; conversely, the larger the contact angle, the worse the wettability.

[0075] In this embodiment, the first contact angle can characterize the degree of spreading of the electrolyte on the surface of the liquid storage member 200, the second contact angle can characterize the degree of spreading of the electrolyte on the surface of the battery electrode plate, and the third contact angle can characterize the degree of spreading of the electrolyte on the surface of the battery separator. The first contact angle is higher than the second contact angle and / or the third contact angle, which is more conducive to the battery in the middle and late stages of cycling. When the electrolyte inside the battery cell 100 is insufficient, the electrode plate and the separator can adsorb the electrolyte stored in the liquid storage member 200, thereby improving the cycling performance of the battery. Among them, the battery electrode plate and the separator can be arranged inside the battery cell 100, and the liquid storage member 200 can absorb and store the residual electrolyte outside the battery cell 100.

[0076] In some embodiments, the first contact angle is greater than or equal to 25° and less than or equal to 50°.

[0077] In this embodiment, the first contact angle of the liquid storage member 200 with respect to the electrolyte, the first contact angle is greater than or equal to 25° and less than or equal to 50°. At this time, the minimum value of the second contact angle and / or the third contact angle provided by the present application can be less than 25°, and the maximum value of the second contact angle and / or the third contact angle can be less than 50°.

[0078] Specifically, the differences between the first contact angle and the second contact angle, and between the first contact angle and the third contact angle are both small. Furthermore, it is more beneficial for the battery in the middle and late stages of cycling. When the electrolyte inside the battery cell 100 is insufficient, the electrode plate and the separator can adsorb the electrolyte stored in the liquid storage member 200, thereby improving the cycling performance of the battery. Among them, the difference can be 0.05, 0.1, 0.15, 0.2, 0.25, etc., and specifically can be between 0 and 1.

[0079] In some embodiments, such as Figure 3 , Figure 4 , Figure 5 and Figure 6 shown, the battery cell 100 includes a first surface, and the liquid storage member 200 includes a first liquid storage portion 201 provided on the first surface or / and a second liquid storage portion 202 provided on the first surface; wherein, a positive electrode tab 101 and a negative electrode tab 102 are provided on the first surface, the first liquid storage portion 201 is located on one side of the positive electrode tab 101 away from the negative electrode tab 102, or / and, the second liquid storage portion 202 is located on one side of the negative electrode tab 102 away from the positive electrode tab 101.

[0080] In this embodiment, such as Figure 3 , Figure 4 , Figure 5 and Figure 6 shown, the first surface can be located at the top of the battery cell 100, that is, the positive electrode tab 101 and the negative electrode tab 102 can be provided at the top of the battery cell 100, and the positive electrode tab 101 and the negative electrode tab 102 can be symmetrically arranged at the top. The liquid storage member 200 can include a first liquid storage portion 201 and a second liquid storage portion 202. The first liquid storage portion 201 and the second liquid storage portion 202 can be provided at the idle position at the top of the battery cell 100 and not be below the explosion-proof valve 303 of the battery, which can not only avoid interfering with the opening of the explosion-proof valve 303, but also be close to the electrode tabs of the battery. Furthermore, it is more beneficial for the battery in the middle and late stages of cycling. When the electrolyte inside the battery cell 100 is insufficient, the electrode plate and the separator can adsorb the electrolyte stored in the liquid storage member 200, thereby improving the cycling performance of the battery.

[0081] In some embodiments, such as Figure 3 , Figure 4 , Figure 5 and Figure 6 shown, the battery cell 100 further includes a second surface and a third surface. The second surface and the third surface are corresponding surfaces of the battery cell 100. The liquid storage member 200 further includes a third liquid storage portion 203 provided on the second surface or / and a fourth liquid storage portion 204 provided on the third surface; wherein, the third liquid storage portion 203 is connected to the first liquid storage portion 201, or / and, the fourth liquid storage portion 204 is connected to the second liquid storage portion 202.

[0082] In this embodiment, such as Figure 3 ,Figure 4 , Figure 5 and Figure 6 As shown in Figure 4 , Figure 5 and Figure 6 , the second surface and the third surface can be two corresponding sides of the battery cell 100, which can be understood as the left side and the right side. The liquid storage member 200 can include a third liquid storage portion 203 and a fourth liquid storage portion 204. The third liquid storage portion 203 can be disposed on the left side of the battery cell 100, and the fourth liquid storage portion 204 can be disposed on the right side of the battery cell 100. Both the third liquid storage portion 203 and the fourth liquid storage portion 204 can extend upward to connect the third liquid storage portion 203 with the first liquid storage portion 201 and connect the fourth liquid storage portion 204 with the second liquid storage portion 202. At the same time, both the third liquid storage portion 203 and the fourth liquid storage portion 204 can extend downward to be close to the bottom of the battery cell 100, thereby avoiding the enrichment of the residual electrolyte in the bottom of the battery housing 400.

[0083] In some embodiments, the positive electrode tab 101 and the negative electrode tab 102 can be disposed on different sides of the battery cell 100. That is, the positive electrode tab 101 can be disposed on the first surface, and the negative electrode tab 102 can be disposed on the second surface; or the positive electrode tab 101 can be disposed on the first surface, and the negative electrode tab 102 can be disposed on the third surface; or the positive electrode tab 101 can be disposed on the first surface, and the negative electrode tab 102 can be disposed on the fourth surface; or the positive electrode tab 101 can be disposed on the second surface, and the negative electrode tab 102 can be disposed on the first surface; or the positive electrode tab 101 can be disposed on the second surface, and the negative electrode tab 102 can be disposed on the third surface; or the positive electrode tab 101 can be disposed on the second surface, and the negative electrode tab 102 can be disposed on the fourth surface; or the positive electrode tab 101 can be disposed on the third surface, and the negative electrode tab 102 can be disposed on the first surface; or the positive electrode tab 101 can be disposed on the third surface, and the negative electrode tab 102 can be disposed on the second surface; or the positive electrode tab 101 can be disposed on the third surface, and the negative electrode tab 102 can be disposed on the fourth surface; or the positive electrode tab 101 can be disposed on the fourth surface, and the negative electrode tab 102 can be disposed on the first surface; or the positive electrode tab 101 can be disposed on the fourth surface, and the negative electrode tab 102 can be disposed on the second surface; or the positive electrode tab 101 can be disposed on the fourth surface, and the negative electrode tab 102 can be disposed on the third surface.

[0084] It should be noted that the positive electrode tab 101 and the negative electrode tab 102 can be disposed on the same side of the battery cell 100. That is, the positive electrode tab 101 and the negative electrode tab 102 can be disposed on the first surface at the same time, or can be disposed on the second surface at the same time, or can be disposed on the third surface at the same time, or can be disposed on the fourth surface at the same time. The positions of the positive electrode tab 101 and the negative electrode tab 102 can be selected according to actual applications, and the present application does not make specific limitations.

[0085] In some embodiments, such as Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the battery cell 100 further includes a fourth surface, and the liquid storage member 200 further includes a fifth liquid storage portion 205; wherein, the fourth surface and the first surface are corresponding surfaces of the battery cell 100, and both ends of the fifth liquid storage portion 205 are respectively connected to the third liquid storage portion 203 and the fourth liquid storage portion 204.

[0086] In this embodiment, the fourth surface may be located at the bottom of the battery cell 100. The liquid storage member 200 further includes a fifth liquid storage portion 205, which may be disposed at the bottom of the battery cell 100 and is respectively connected to the third liquid storage portion 203 and the fourth liquid storage portion 204, so as to further adsorb and store the residual electrolyte in the battery housing 400, avoiding the enrichment of the electrolyte at the bottom. Wherein, the width D of the fifth liquid storage portion 205 along the left and right sides of the battery cell 100 may be less than or equal to the thickness W of the battery cell 100.

[0087] In some embodiments, as Figure 2 and Figure 6 shown, the present application further provides a battery, which includes:

[0088] A battery cell 100, provided with corresponding first and fourth surfaces;

[0089] A liquid storage member 200, configured to store a part of the electrolyte of the battery;

[0090] Wherein, the liquid storage member 200 includes a fifth liquid storage portion 205, and the fifth liquid storage portion 205 is disposed at the fourth surface;

[0091] The battery cell 100 is provided with a positive electrode tab 101 and a negative electrode tab 102. The positive electrode tab 101 and the negative electrode tab 102 are disposed on the first surface, or the positive electrode tab 101 and the negative electrode tab 102 are respectively located on adjacent sides of the battery cell 100 and one of them is disposed on the first surface.

[0092] Specifically, the battery provided by the present application includes a battery cell 100 and a liquid storage member 200. The battery cell 100 is provided with corresponding first and fourth surfaces. The liquid storage member 200 is configured to store a part of the electrolyte of the battery. At the same time, the liquid storage member 200 includes a fifth liquid storage portion 205 disposed at the fourth surface. The battery cell 100 is provided with a positive electrode tab 101 and a negative electrode tab 102. The positive electrode tab 101 and the negative electrode tab 102 are disposed on the first surface, or the positive electrode tab 101 and the negative electrode tab 102 are respectively located on adjacent sides of the battery cell 100 and one of them is disposed on the first surface. Thus, it is possible to not only improve the liquid retention amount of the battery without reducing the energy density of the battery, but also facilitate the battery to feedback to the battery cell 100 in the middle and later stages of long-term cycling, improving the cycling performance of the battery and avoiding the performance deterioration caused by the enrichment of the residual electrolyte inside the battery housing at the bottom.

[0093] In some embodiments, the thickness ratio between the first liquid storage part 201 and the third liquid storage part 203 is greater than or equal to 2 and less than or equal to 30; and / or, the thickness ratio between the first liquid storage part 201 and the fourth liquid storage part 204 is greater than or equal to 2 and less than or equal to 30; and / or, the thickness ratio between the first liquid storage part 201 and the fifth liquid storage part 205 is greater than or equal to 2 and less than or equal to 30; and / or, the thickness ratio between the second liquid storage part 202 and the third liquid storage part 203 is greater than or equal to 2 and less than or equal to 30; and / or, the thickness ratio between the second liquid storage part 202 and the fourth liquid storage part 204 is greater than or equal to 2 and less than or equal to 30; and / or, the thickness ratio between the second liquid storage part 202 and the third liquid storage part 203 is greater than or equal to 2 and less than or equal to 30.

[0094] In this embodiment, by setting the thickness ratios between the first liquid storage part 201 and the third liquid storage part 203, between the first liquid storage part 201 and the fourth liquid storage part 204, between the first liquid storage part 201 and the fifth liquid storage part 205, between the second liquid storage part 202 and the third liquid storage part 203, between the second liquid storage part 202 and the fourth liquid storage part 204, and between the second liquid storage part 202 and the third liquid storage part 203 within the range of 2 to 30, it is possible to better avoid the enrichment of the residual electrolyte at the bottom inside the battery case 400 without increasing the volume of the battery, and it is also beneficial for the first liquid storage part 201 and the second liquid storage part 202 to store more electrolyte, thereby facilitating the electrolyte to better enter the inside of the electrode sheet from top to bottom during the later stage of the cycle.

[0095] Furthermore, in some embodiments, the thickness of the first liquid storage part 201 and the second liquid storage part 202 is greater than or equal to 1 mm and less than or equal to 3 mm, and the thickness of the third liquid storage part 203, the fourth liquid storage part 204, and the fifth liquid storage part 205 is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

[0096] In some embodiments, the first liquid storage part 201, the second liquid storage part 202, the third liquid storage part 203, the fourth liquid storage part 204, and the fifth liquid storage part 205 are integrally formed to form the liquid storage member 200.

[0097] In this embodiment, the first liquid storage part 201, the second liquid storage part 202, the third liquid storage part 203, the fourth liquid storage part 204, and the fifth liquid storage part 205 are integrally formed to form the liquid storage member 200, thereby facilitating the electrolyte to better enter the inside of the electrode sheet from top to bottom during the later stage of the cycle.

[0098] In some embodiments, such as Figure 6As shown, the battery further includes a top cover 300; wherein, the top cover 300 is configured to encapsulate the first surface, and a positive terminal 301 and a negative terminal 302 are provided on a side of the top cover 300 away from the first surface. The positive terminal 301 is connected to the positive tab 101, and the negative terminal 302 is connected to the negative tab 102.

[0099] In this embodiment, the top cover 300 can be made of aluminum material and can be manufactured by processes such as stamping, injection molding, and welding. The positive terminal 301 and the negative terminal 302 are provided on the top cover 300 for electrically connecting the positive and negative electrodes inside the battery to the external circuit. The positive terminal 301 and the negative terminal 302 are respectively connected to the positive tab 101 and the negative tab 102, which can form a charge and discharge circuit, enabling the battery to effectively exchange energy with an external load.

[0100] In some embodiments, as Figure 6 shown, the positive terminal 301 is connected to the positive tab 101 by a positive adapter piece 103, and the negative terminal 302 is connected to the negative tab 102 by a negative adapter piece 104. In this embodiment, the positive tab 101 and the positive terminal 301 are welded and connected through the positive adapter piece 103, while the positive tab 101 and the negative terminal 302 are welded and connected through the negative adapter piece 104.

[0101] In some embodiments, as Figure 6 shown, an explosion-proof valve 303 is further provided on the top cover 300, and the explosion-proof valve 303 is provided between the positive terminal 301 and the negative terminal 302.

[0102] The explosion-proof valve 303 is a key safety device for preventing the battery from exploding due to overvoltage or overheating during charging, discharging, or abnormal operating conditions. Its main function is to automatically open the valve and release the internal high-pressure gas when the internal pressure or temperature of the battery exceeds the set value, thereby achieving the purpose of explosion prevention.

[0103] In some embodiments, as Figure 2 and Figure 6 shown, the battery further includes a housing 400; wherein, the housing 400 is configured to assemble the liquid storage member 200 and the battery cell 100.

[0104] In this embodiment, after the liquid storage member 200 is disposed on the surface of the battery cell 100, it can be assembled into the cavity of the housing 400 together with the battery cell 100. At the same time, after the electrolyte is filled in the battery cell 100, the electrolyte will overflow into the cavity and be adsorbed and stored by the liquid storage member 200 in the cavity. Thus, the battery can feedback to the battery cell 100 in the middle and later stages of long cycling, improving the cycling performance of the battery and avoiding performance deterioration caused by the enrichment of the residual electrolyte at the bottom inside the housing 400 of the battery.

[0105] In some embodiments, the battery further includes a protective film 500 configured to wrap the housing 400 to protect the battery cell 100.

[0106] In this embodiment, the protective film 500 can be a Mylar film, which is used to protect the battery cell 100 to prevent the battery cell 100 from being scratched or short-circuited during the assembly process. At the same time, the Mylar film can also play a role in sealing and insulation, thereby ensuring the stability and safety of the electrolyte inside the battery. For example, the Mylar film can prevent the leakage of the electrolyte, and by designing its structure (such as a micro-convex structure), the liquid injection efficiency and wetting effect can be improved. Among them, the Mylar film is a oriented polyester film with excellent physical and chemical properties, such as chemical resistance, dimensional stability, thermal stability, etc.

[0107] The battery provided by the present application will be specifically described below.

[0108] Provide respectively Figure 1 the batteries shown, and three groups Figure 2 the batteries shown, which can be defined as Comparative Example 1, Example 1, Example 2, and Example 3 respectively. Among them, an insulating film 20 is used between the housing and the battery cell in the battery of Comparative Example 1; the liquid storage members 200 in Example 1, Example 2, and Example 3 are all provided on two sides, the bottom, and the top of the battery cell 100. The liquid storage capacity value of the liquid storage member 200 in Example 1 is 15 and the first contact angle is 34°. The liquid storage capacity value of the liquid storage member 200 in Example 2 is 8 and the first contact angle is 46°. The liquid storage capacity value of the liquid storage member 200 in Example 3 is 20 and the first contact angle is 31°.

[0109] The batteries provided in Comparative Example 1, Example 1, Example 2, and Example 3 are subjected to constant current charge and discharge cycling 2000 times at 45 °C at a rate of 1.0C (nominal capacity), and the capacity retention rate (C%) after 2000 cycles is calculated as (discharge capacity of the 2000th cycle / first discharge capacity) × 100%. It can be obtained that the cycling capabilities of Comparative Example 1, Example 1, Example 2, and Example 3 are 74.5%, 81.6%, 82.3%, and 83.7% respectively. It can be seen that by providing a liquid storage member on the surface of the battery cell, the present application can realize improving the liquid retention amount of the battery without reducing the energy density of the battery, and it is also convenient for the battery to feedback to the battery cell in the middle and later stages of long cycling, improving the cycling performance of the battery, and avoiding the performance deterioration caused by the enrichment of the residual electrolyte inside the housing of the battery at the bottom.

[0110] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all 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, characterized in that: include: Battery cell (100); A liquid storage member (200) is arranged on the surface of the battery core (100); The liquid storage component (200) is configured to store part of the electrolyte of the battery, and the liquid storage capacity value of the liquid storage component (200) is greater than or equal to a preset first threshold value, and less than or equal to a preset second threshold value; The ratio between the second threshold value and the first threshold value is greater than 1 and less than or equal to 3.75; the liquid storage capacity value is configured to represent the storage amount of the electrolyte stored in the liquid storage element (200) per unit gram weight.

2. The battery according to claim 1, characterized in that The first threshold is greater than 0 and less than or equal to 8 g / g; the second threshold is greater than or equal to 8 g / g and less than or equal to 30 g / g.

3. The battery according to claim 1, characterized in that The liquid storage capacity value satisfies: Wherein, P is the liquid storage capacity value g / g, α is the oil absorption value g / cm of the liquid storage member (200) 3 , β is the porosity of the liquid storage component (200), V is the volume of the liquid storage component (200), cm 3 , m is the mass g of the liquid storage component (200).

4. The battery according to claim 1, characterized in that The first contact angle of the liquid storage element (200) to the electrolyte is higher than the second contact angle of the battery electrode to the electrolyte and / or the third contact angle of the battery diaphragm to the electrolyte.

5. The battery according to claim 4, characterized in that The first contact angle is greater than or equal to 25° and less than or equal to 50°.

6. The battery according to any one of claims 1 to 5, characterized in that The battery further comprises a top cover (300), wherein the top cover (300) is configured to encapsulate the battery cell (100); The battery cell (100) comprises a first surface, and the liquid storage member (200) comprises a first liquid storage portion (201) arranged on the first surface and / or a second liquid storage portion (202) arranged on the first surface; the first surface is arranged on a side of the battery cell (100) facing the top cover (300).

7. The battery according to claim 6, characterized in that The battery cell (100) is also provided with a positive electrode lug (101) and a negative electrode lug (102); a positive electrode column (301) and a negative electrode column (302) are provided on a side of the top cover (300) away from the first surface; the positive electrode column (301) is connected to the positive electrode lug (101), and the negative electrode column (302) is connected to the negative electrode lug (102).

8. The battery according to claim 7, characterized in that The positive electrode ear (101) and the negative electrode ear (102) are both located on the same side of the battery cell (100), the first liquid storage portion (201) is located on the side of the positive electrode ear (101) away from the negative electrode ear (102), or / and the second liquid storage portion (202) is located on the side of the negative electrode ear (102) away from the positive electrode ear (101).

9. The battery according to claim 8, characterized in that The positive electrode tab (101) and the negative electrode tab (102) are both arranged on the first surface.

10. The battery according to claim 7, characterized in that The positive electrode tab (101) and the negative electrode tab (102) are respectively located on different sides of the battery cell (100).

11. The battery according to claim 6, characterized in that The battery cell (100) further comprises a second surface and a third surface, the second surface and the third surface being surfaces corresponding to the battery cell (100), and the liquid storage member (200) further comprises a third liquid storage portion (203) provided on the second surface and / or a fourth liquid storage portion (204) provided on the third surface; Wherein, the third liquid storage part (203) is connected to the first liquid storage part (201), or / and, the fourth liquid storage part (204) is connected to the second liquid storage part (202).

12. The battery according to claim 11, characterized in that The battery core (100) further includes a fourth surface, and the liquid storage member (200) further includes a fifth liquid storage portion (205); The fourth surface and the first surface are surfaces corresponding to the battery cell (100), and two ends of the fifth liquid storage portion (205) are respectively connected to the third liquid storage portion (203) and the fourth liquid storage portion (204).

13. The battery according to claim 12, characterized in that The thickness ratio between the first liquid storage part (201) and the third liquid storage part (203) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the first liquid storage part (201) and the fourth liquid storage part (204) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the first liquid storage part (201) and the fifth liquid storage part (205) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the second liquid storage part (202) and the third liquid storage part (203) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the second liquid storage portion (202) and the fourth liquid storage portion (204) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the second liquid storage portion (202) and the third liquid storage portion (203) is greater than or equal to 2 and less than or equal to 30.

14. The battery according to claim 13, characterized in that The thickness of the first liquid storage section (201) and / or the thickness of the second liquid storage section (202) is greater than or equal to 1 mm and less than or equal to 3 mm, and the thickness of the third liquid storage section (203) and / or the thickness of the fourth liquid storage section (204) and / or the thickness of the fifth liquid storage section (205) is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

15. The battery according to claim 12, characterized in that When the liquid storage component includes a first liquid storage portion (201), a second liquid storage portion (202), a third liquid storage portion (203), a fourth liquid storage portion (204) and a fifth liquid storage portion (205), the first liquid storage portion (201), the second liquid storage portion (202), the third liquid storage portion (203), the fourth liquid storage portion (204) and the fifth liquid storage portion (205) are integrally formed to form the liquid storage component (200).

16. The battery according to claim 7, characterized in that The positive electrode column (301) is connected to the positive electrode lug (101) using a positive electrode adapter sheet (103), and the negative electrode column (302) is connected to the negative electrode lug (102) using a negative electrode adapter sheet (104).

17. The battery according to claim 7, characterized in that The top cover (300) is also provided with an explosion-proof valve (303), and the explosion-proof valve (303) is arranged between the positive pole (301) and the negative pole (302).

18. The battery according to any one of claims 1 to 5, characterized in that The battery also includes a housing (400); The housing (400) is configured to assemble the liquid storage component (200) and the battery cell (100).

19. The battery according to claim 18, characterized in that The battery further comprises a protective film (500), wherein the protective film (500) is configured to wrap the housing (400) to protect the battery cell (100).

20. The battery according to any one of claims 1 to 5, characterized in that The liquid storage member (200) is at least one of a liquid storage member (200) made of polyethylene fiber material, a liquid storage member (200) made of polypropylene fiber material, a liquid storage member (200) made of polyester fiber material, a liquid storage member (200) made of aramid material, a liquid storage member (200) made of polyurethane material, a liquid storage member (200) made of polyamide material, a liquid storage member (200) made of alkylethylene polymer material, a liquid storage member (200) made of polylactic acid material, and a liquid storage member (200) made of acrylate-styrene copolymer material.

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