Restraining tray for battery

Abstract

The invention provides a restraining tray for a battery. The restraining tray for the battery is provided with a battery containing groove, and at least part of the inner wall of the battery containing groove is provided with a gasket. The compression modulus of the gasket is larger than or equal to 100 MPa. The restraining tray for the battery not only has longer service life, but also can apply stable restraining force to the battery in the formation process of the battery, so that the problem that the thickness of the battery exceeds a specified standard due to excessive expansion of a pole core in the formation process is prevented, the problem that a pole piece is wrinkled in the charging process is effectively inhibited, and the battery quality is improved. The interface between the pole piece and the diaphragm is in good contact in the whole formation process, and the formation effect of the battery is improved, so that the consistency of the electrochemical performance of the battery is improved.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage batteries, and in particular to a restraint tray for batteries. Background Art

[0002] As environmental pollution becomes increasingly prominent, humans are in urgent need of replacing polluting traditional energy with environmentally friendly new energy. Among new energy sources, wind and solar energy are often affected by weather, are intermittent and volatile, and are prone to problems such as mismatch between peak power generation and peak power consumption, as well as challenges such as insufficient grid regulation and increased difficulty in frequency stability. Therefore, energy storage technology is needed to match them to achieve peak load shaving and valley filling.

[0003] As an important component of electrochemical energy storage, lithium-ion batteries have been widely used due to their high energy density, long service life, low self-discharge rate, no memory effect and environmental friendliness. In the production of lithium-ion batteries, an important production link is formation, which mainly plays the role of activating the battery. However, during the formation process, lithium-ion batteries are prone to gas production, and the negative electrode expands due to the embedding of lithium ions, which may cause the diaphragm to shrink and the pole piece to wrinkle, ultimately affecting the appearance and performance of the battery. In order to avoid the above problems, the prior art often places the battery in a restraint tray for formation. During the formation process of the battery, a restraining force is applied to the battery to clamp the battery, thereby preventing the battery from swelling.

[0004] CN210074090U discloses a battery pressurized restraint tray, which can be equipped with a variety of width liners and length liners of different sizes. The width liners are detachably installed at the ends of the battery slot along the width direction, and the length liners are detachably installed at the ends of the battery slot along the length direction, so as to improve the compatibility of the battery pressurized restraint tray. However, when the battery pressurized restraint tray is restrained and pressurized, the battery will be completely surrounded by the battery slot, and the restraining force applied will first squeeze the raised part of the shell, making it difficult for the restraining force to act directly on the pole core, so that the expansion of the pole core cannot be effectively suppressed, and it is also difficult to effectively suppress the problem of pole piece wrinkles caused by diaphragm shrinkage, which reduces the electrochemical performance of the battery.

[0005] In order to more effectively suppress battery expansion, CN216120440U discloses a restraint tray for uniform pressure formation of square aluminum shell batteries, wherein a silicone gasket is arranged between the battery separator and the square aluminum shell battery, and the length of the silicone gasket is less than the length of the square aluminum shell battery, and the width is less than the width of the square aluminum shell battery. The restraint tray can make the battery cells more uniformly stressed and heated, improve the quality of the SEI film formed during formation, which is beneficial to the performance of the battery, and is not easy to scratch the battery shell during the formation process. However, the silicone gasket is a flexible material, and after each application of the restraining force, the silicone gasket will rebound, which is likely to cause the deformation of the battery and the restraining force to be unstable, which is not conducive to the consistency of the battery; and after each application of pressure, the silicone gasket will produce a large deformation, and after multiple applications of pressure, the silicone gasket may not be able to rebound completely, so that the thickness of the silicone gasket has changed significantly compared with the initial thickness, which in turn causes the silicone gasket to fail, affecting the service life of the restraint tray.

[0006] Therefore, it is necessary to provide a new battery restraint tray, which not only has a long service life, but also can apply a stable restraining force to the battery during the formation process of the battery, preventing the electrode core from excessively expanding during the formation process and causing the battery thickness to exceed the specified standard. At the same time, it can effectively suppress the wrinkling problem of the electrode sheet in the battery during the charging process, so that the interface between the electrode sheet and the diaphragm is in better contact during the entire formation process, thereby improving the formation effect of the battery, thereby obtaining a battery with high consistency of electrochemical performance. Summary of the invention

[0007] The embodiment of the present application provides a battery restraint tray, which not only has a long service life, but also can apply a stable restraining force to the battery during the formation process of the battery, thereby preventing the electrode core from excessively expanding during the formation process and causing the battery thickness to exceed the specified standard. At the same time, it effectively suppresses the wrinkling problem of the electrode sheet in the battery during the charging process, ensures good interface contact between the electrode sheet and the diaphragm, improves the formation effect of the battery, and thus obtains a battery with high consistency of electrochemical performance.

[0008] A battery restraint tray, wherein the battery restraint tray has a battery receiving slot, and at least a portion of the inner wall of the battery receiving slot is provided with a gasket;

[0009] The compression modulus of the gasket is ≥100 MPa.

[0010] When the battery restraint tray of the present application clamps the battery during the formation process, it can promote the discharge of gas generated during the formation process, avoid excessive expansion of the battery, effectively suppress the wrinkling problem of the battery pole piece during the charging process, improve the formation effect of the battery, and thus improve the electrochemical performance of the battery. At the same time, the compression modulus of the gasket in the battery restraint tray of the embodiment of the present application is ≥100MPa. After each application of the restraining force, the gasket itself will undergo a slight deformation, and it is not easy to rebound significantly, so that the restraining force on the battery can be kept stable, which is helpful for the consistency of the formation interface, and thus can improve the thickness consistency and capacity consistency of the battery; and because the gasket in the present application undergoes only a slight deformation after multiple applications of pressure, and the thickness of the gasket hardly changes significantly, the gasket has a long service life, which helps to extend the service life of the battery restraint tray.

[0011] As described above, in the battery restraint tray, when the gasket is selected from glass fiber gasket, aluminum alloy gasket or stainless steel gasket, during the battery formation process, if the gasket contacts with the electrolyte, the gasket is not easily corroded by the electrolyte, which helps to extend the service life of the battery restraint tray.

[0012] In the above-mentioned restraint tray for a battery, the spacer has a through hole in the thickness direction.

[0013] When the gasket has through holes in the thickness direction, it can not only help dissipate heat of the battery during the formation process and improve the safety of the formation process, but also reduce the amount of gasket used and save production costs.

[0014] In the battery restraint tray as described above, the cross-sectional area of ​​the through hole accounts for 30-70% of the surface area of ​​the gasket.

[0015] When the cross-sectional area of ​​the through hole accounts for 30-70% of the surface area of ​​the gasket, the heat dissipation of the battery during the formation process can be improved without excessive compression of the battery shell and excessive expansion of the battery, thereby improving the safety of the formation process.

[0016] As described above, in the battery restraint tray, wherein the thickness of the gasket is 1-100 mm, it can save gasket material and thus production costs while avoiding excessive squeezing of the battery shell during the formation process, avoiding excessive expansion of the battery, and maintaining the consistency of the battery.

[0017] The battery restraint tray as described above, wherein the battery receiving slot is used to receive a battery, the battery comprises a shell and a pole core, the shell has a pole core receiving cavity, the pole core is received in the pole core receiving cavity, and at least a portion of the outer surface of the shell is disposed adjacent to the gasket;

[0018] The outer edge of the orthographic projection of the gasket on the surface of the pole core opposite to the gasket is located within the edge of the surface of the pole core opposite to the gasket.

[0019] When the outer edge of the gasket's orthographic projection on the surface is within the edge of the surface, it means that the surface of the gasket is smaller than the surface of the pole core. During the formation process of the battery, the gasket can fully squeeze the pole core in the battery, avoid the bulge of the battery shell from being subjected to force, further promote the discharge of gas generated during the formation process, avoid excessive expansion of the battery, effectively suppress the wrinkling problem of the battery pole piece during the charging process, and improve the electrochemical performance of the battery.

[0020] The battery restraint tray as described above, wherein the dimension of the gasket extending in the first direction accounts for 60-90% of the dimension of the surface of the pole core arranged opposite thereto extending in the first direction; and / or,

[0021] The dimension of the gasket extending in the second direction accounts for 60-90% of the dimension of the surface of the pole core arranged opposite thereto extending in the second direction, and the second direction is perpendicular to the first direction.

[0022] In the present application, when the dimension of the gasket extending in the first direction accounts for the dimension of the surface of the pole core arranged opposite to it extending in the first direction, and / or the dimension of the gasket extending in the second direction accounts for the dimension of the surface of the pole core arranged opposite to it extending in the second direction, and when the above relationship is satisfied, the gasket can be used to more fully and directly squeeze the pole core while saving gaskets, thereby avoiding excessive deformation of the protrusion of the shell due to squeezing, and at the same time avoiding excessive expansion of the battery during the formation process, avoiding wrinkles on the pole piece, and improving the electrochemical performance of the battery.

[0023] The battery restraint tray as described above, wherein the corners of the gasket are rounded. By rounding the corners of the gasket, the gasket is not likely to damage the battery shell when the battery restraint tray applies a restraining force, and the battery can be prevented from over-expanding and wrinkling of the electrode while keeping the shell intact.

[0024] The battery restraint tray as described above, wherein the battery restraint tray further comprises an outer frame and a partition, wherein the partition is arranged inside the outer frame to divide the outer frame into N battery receiving slots, where N≥2;

[0025] The gasket is arranged on at least a portion of the surface of the partition.

[0026] The present application uses partitions to divide the outer frame into N battery accommodating slots, which can realize batch formation of batteries and improve production efficiency.

[0027] The battery restraint tray as described above, wherein the battery restraint tray further comprises an outer frame, a partition and a support, wherein the partition is arranged inside the outer frame to divide the outer frame into N battery receiving slots, where N≥2;

[0028] The support member is arranged on at least a portion of the surface of the partition, and the gasket is arranged on at least a portion of the surface of the support member away from the partition.

[0029] In the present application, the size of the support member can be selected according to the size of the battery, and the support member can be used to adjust the space of the battery receiving slot, so that the battery restraint tray of the present application can be suitable for batteries of more sizes.

[0030] Compared with the prior art, this application has at least the following beneficial effects:

[0031] 1) The battery restraint tray of the present application can promote the discharge of gas generated during the formation process when used to clamp the battery, avoid excessive expansion of the battery, effectively suppress the wrinkling problem of the battery pole piece during the charging process, improve the formation effect of the battery, and thus improve the electrochemical performance of the battery;

[0032] 2) The compression modulus of the gasket in the battery restraint tray of the embodiment of the present application is ≥100MPa. After each application of the restraining force, the gasket with a specific compression modulus in the present application is not easy to rebound, so that the restraining force on the battery can be kept stable, which helps to obtain a battery with high consistency in thickness and capacity;

[0033] 3) After multiple pressures are applied, the gasket in the present application undergoes only slight deformation, and the thickness of the gasket hardly changes significantly. The gasket has a long service life, which helps to extend the service life of the battery restraint tray;

[0034] 4) The battery restraint tray of the present application helps to discharge the gas generated by the battery during the formation process, and helps to dissipate the heat of the battery during the formation process, thereby improving the safety of the formation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technology descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 This is a schematic diagram of the surface structure of the gasket in the first embodiment of the present application;

[0037] Figure 2 This is a schematic diagram of the surface structure of the gasket in the second embodiment of the present application;

[0038] Figure 3 This is a schematic diagram of the surface structure of a gasket in the third embodiment of the present application;

[0039] Figure 4 This is a schematic diagram of the structure of a battery in some embodiments of the present application;

[0040] Figure 5 A top view of a battery restraint tray in a first embodiment of the present application;

[0041] Figure 6 A top view of a battery restraint tray in a second embodiment of the present application;

[0042] Figure 7 A top view of a battery restraint tray in a third embodiment of the present application;

[0043] Figure 8 It is a capacity diagram of the battery after being formed with a restraint tray in Example 1 and Comparative Example 1 of the present application;

[0044] Fig. 9 This is a morphology diagram of the electrode in the battery after the battery is formed by the restraint tray in Example 1 of the present application;

[0045] Fig.10 This is a morphology diagram of the battery electrode after the battery injection molding tray is formed in Comparative Example 2 of the present application;

[0046] Fig.11 It is a cycle capacity curve diagram of the battery after being formed by the restraint tray for the battery in Example 1 of the present application and the injection molded tray for the battery in Comparative Example 2.

[0047] Description of reference numerals:

[0048] 11: Gasket;

[0049] 12: outer frame;

[0050] 13: Battery;

[0051] 14: partition;

[0052] 15: Supporting member;

[0053] 111: rounded corners;

[0054] 112: through hole;

[0055] 131: Pole core;

[0056] 132: Shell. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The terms used in the implementation mode of this application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. The implementation mode of the embodiments of the present application will be described in detail in combination with the accompanying drawings.

[0058] The embodiment of the present application provides a battery restraint tray, the battery restraint tray having a battery receiving slot, at least part of the inner wall of the battery receiving slot being provided with a gasket;

[0059] The compression modulus of the gasket is ≥100MPa.

[0060] The battery restraint tray of the present application has a battery receiving slot, which is used to accommodate the battery. The battery restraint tray applies a restraining force to the battery through the side wall of the battery receiving slot to prevent the battery from over-expanding during the formation process.

[0061] The present application does not specifically limit the specific shape of the battery receiving groove, as long as the shape of the battery receiving groove can match the shape of the battery. For example, the shape of the battery is a hexahedral structure, and the shape of the battery receiving groove can be a hexahedral cavity.

[0062] In the present application, a gasket may be provided on a portion of the inner wall of the battery receiving slot, or may be provided on the entire inner wall of the battery receiving slot, and the gasket is located between the battery and the inner wall of the battery receiving slot.

[0063] In some embodiments, a gasket may be provided between the side of the battery and the inner wall of the battery receiving groove; a gasket may be provided between the bottom surface of the battery and the battery receiving groove; a gasket may be provided between the side of the battery and the inner wall of the battery receiving groove, and a gasket may be provided between the bottom surface of the battery and the battery receiving groove at the same time.

[0064] Specifically, the gasket disposed between the side surface of the battery and the inner wall of the battery receiving groove, and / or the gasket disposed between the bottom surface of the battery and the battery receiving groove may be an integral structure or a split structure;

[0065] When the gasket is a split structure, M gaskets are randomly arranged between the side of the battery and the inner wall of the battery receiving groove, and / or, M gaskets are randomly arranged between the side of the battery and the inner wall of the battery receiving groove, M≥2.

[0066] Illustratively, the compression modulus of the gasket in the present application may be 100 MPa, 101 MPa, 200 MPa, 400 MPa, 800 MPa, 2000 MPa, 4000 MPa, or a range consisting of any two of them.

[0067] The compression modulus of the present application refers to the stress required for a material to produce a unit deformation under pressure. In some embodiments, the compression modulus of the gasket can be obtained by Formula 1.

[0068]

[0069] In formula 1, l is the initial thickness of the gasket;

[0070] S is the surface area of ​​the gasket;

[0071] F is the force applied perpendicularly to the gasket surface;

[0072] △l is the change in gasket thickness before and after force is applied.

[0073] In a specific embodiment, F may be 8000N.

[0074] When the battery restraint tray of the present application applies a restraining force to the battery, the gasket can squeeze the pole core, which can promote the discharge of the gas generated during the formation process, avoid excessive expansion of the battery, effectively suppress the wrinkling problem of the battery pole piece during the charging process, improve the formation effect of the battery, and thus improve the electrochemical performance of the battery. At the same time, compared with the existing silicone gaskets (compression modulus is usually around 15MPa), the gasket with a specific compression modulus in the present application has a small rebound after each restraining force is applied, which can keep the restraining force on the battery stable, help to obtain a battery with high thickness consistency and high capacity consistency, and broaden the application scenarios of the battery; and after the gasket in the present application is subjected to multiple pressures, the gasket itself only undergoes a slight deformation, and the thickness of the gasket hardly changes significantly. The gasket has a long service life, which helps to extend the service life of the battery restraint tray.

[0075] The battery restraint tray of the present application can be used in any battery formation process. For example, the battery can be a lead-acid battery, a sodium battery, a magnesium battery, an aluminum battery, a potassium battery or a lithium-ion battery.

[0076] In some embodiments, the battery restraint tray of the present application can be particularly used for batteries with a wound structure (including batteries with a core), which can prevent the pole pieces in the core from wrinkling during the formation process and improve the electrochemical performance of the battery.

[0077] Furthermore, when the compression modulus of the gasket is 100-1000 MPa, the expansion of the pole core and the wrinkling of the pole piece can be avoided as much as possible without deforming the separator, so that the battery has better electrochemical performance.

[0078] The material of the gasket is not particularly limited in the present application, as long as the compression modulus of the gasket is ≥ 100 MPa. In some embodiments of the present application, the gasket can be selected from a glass fiber gasket, an aluminum alloy gasket or a stainless steel gasket.

[0079] The above-mentioned glass fiber gasket, aluminum alloy gasket or stainless steel gasket can be purchased commercially or made in the laboratory.

[0080] In the present application, the glass fiber gasket is glass fiber reinforced plastic, and the glass fiber gasket may include acrylonitrile butadiene styrene plastic (ABS) and glass fiber. In some embodiments, in the glass fiber gasket, the mass percentage of ABS may be 75%, and the mass percentage of glass fiber may be 25%. During the formation process of the battery, if the glass fiber gasket contacts the electrolyte, it is not easily corroded by the electrolyte, thereby helping to extend the service life of the battery restraint tray.

[0081] The aluminum alloy in the aluminum alloy gasket may be at least one of 1 series aluminum alloy, 2 series aluminum alloy, 3 series aluminum alloy, 4 series aluminum alloy, 5 series aluminum alloy, 6 series aluminum alloy and 7 series aluminum alloy.

[0082] In some embodiments, the surface of the aluminum alloy gasket and the stainless steel gasket may have an anti-corrosion coating. When the electrolyte contacts the gasket during the formation process, the anti-corrosion coating can prevent the electrolyte from corroding the gasket, thereby extending the service life of the battery restraint tray. For example, the anti-corrosion coating may be a Teflon coating.

[0083] The present application does not particularly limit the shape of the gasket, and the surface of the gasket may be a regular shape, such as a circle, a rectangle, a triangle or an ellipse; the surface of the gasket may also be an irregular shape.

[0084] In some embodiments of the present application, when the surface of the gasket is rectangular, the surface shape of the gasket is highly consistent with the outer surface shape of the battery, and the gasket can squeeze the pole core over a larger area, so that the restraining force of the battery restraint tray is more applied to the pole core of the battery, further avoiding excessive expansion of the pole piece in the pole core to produce wrinkles or poor appearance, improving the formation effect, and thereby improving the electrochemical performance of the battery.

[0085] Figure 1 FIG. 1 is a schematic diagram of the surface structure of the gasket in the first embodiment of the present application. Figure 1As shown, in some embodiments of the present application, the corners of the gasket 11 may be rounded.

[0086] For example, Figure 1 As shown, when the surface of the gasket 11 is a rectangle, the four corners of the rectangle can be rounded to make the four corners of the rectangle rounded 111, and each edge of the gasket 11 can be rounded.

[0087] The present application rounds the corners of the gasket 11 so that when the battery restraint tray applies a restraining force, the gasket 11 is not likely to damage the battery casing, thereby preventing the battery from over-expanding and wrinkling the electrode while keeping the casing intact.

[0088] Figure 2 This is a schematic diagram of the surface structure of the gasket in the second embodiment of the present application; Figure 3 FIG. 1 is a schematic diagram of the surface structure of the gasket in the third embodiment of the present application. Figure 2 or Figure 3 As shown, in some embodiments of the present application, the gasket 11 has a through hole 112 in the thickness direction.

[0089] The present application does not particularly limit the shape of the through hole 112 . The cross-sectional shape of the through hole 112 may be a regular shape (eg, circular, triangular, rectangular, elliptical), or an irregular shape.

[0090] Specifically, Figure 2 As shown, the cross-sectional shape of the through hole 112 may be a rectangle; Figure 3 As shown, the cross-sectional shape of the through hole 112 may be circular. It is also understood that the same gasket may have through holes 112 of various shapes.

[0091] In some embodiments, the corners of the through hole 112 on the surface of the gasket 11 may be rounded to further prevent the gasket 11 from damaging the housing during the formation process.

[0092] The present application does not limit the distribution positions of the through holes 112 in the gasket 11 . The through holes 112 may be arranged regularly or irregularly.

[0093] When the gasket 11 has a through hole 112 in the thickness direction, it not only helps to dissipate heat of the battery during the formation process, thereby improving the safety of the formation process, but also can reduce the amount of the gasket 11 used and save production costs.

[0094] Furthermore, in some embodiments of the present application, when the cross-sectional area of ​​the through hole 112 accounts for 30-70% of the surface area of ​​the gasket 11, it is possible to improve the exhaust and heat dissipation of the battery during the formation process without excessive expansion of the battery and wrinkles of the pole piece in the pole core, thereby improving the safety of the battery formation process.

[0095] In some embodiments, the cross-sectional area of ​​the through hole 112 may be considered equal everywhere.

[0096] Exemplarily, the cross-sectional area of ​​the through hole 112 accounts for 30%, 40%, 45%, 50%, 55%, 60%, 65%, 70% of the surface area of ​​the gasket 11 or a range consisting of any two thereof.

[0097] The present application can also further select the thickness of the gasket 11, in order to avoid excessive expansion of the battery during the formation process, prevent the pole piece in the pole core from wrinkling, and maintain the consistency of the battery, thereby saving the material of the gasket 11 and thus saving production costs.

[0098] For example, in some embodiments of the present application, the thickness of the gasket 11 is 1-100 mm.

[0099] Exemplarily, the thickness of the gasket 11 may be 1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 60 mm, 90 mm, 100 mm, or a range consisting of any two of them.

[0100] Furthermore, when the thickness of the gasket 11 is 2-30 mm, the production cost can be further saved while avoiding excessive expansion of the battery and wrinkling of the pole piece.

[0101] Figure 4 Schematic diagram of the structure of the battery in some embodiments of the present application. Figure 4 As shown, in some embodiments of the present application, the battery receiving slot is used to receive the battery 13, the battery 13 includes a shell 132 and a pole core 131, the shell 132 has a pole core receiving cavity, the pole core 131 is received in the pole core receiving cavity, and at least part of the outer surface of the shell 132 is disposed adjacent to the gasket 11;

[0102] The outer edge of the orthographic projection of the gasket 11 on the surface of the pole core 131 opposite to it is located within the edge of the surface of the pole core 131 opposite to it.

[0103] The present application does not specifically limit the pole core 131 , and the pole core 131 may be a pole core 131 commonly used in the art, for example, a wound core or a stacked core.

[0104] The present application does not impose any particular limitation on the housing 132, as long as it can accommodate the pole core 131 and seal the pole core 131. For example, the housing 132 may be an aluminum housing.

[0105] It can be understood that, usually, in order to improve the volume energy density of the battery, the pole core 131 of the battery 13 almost completely occupies the pole core accommodating cavity of the shell 132 (at least 90%).

[0106] In the present application, the surface of the pole core 131 arranged opposite to the gasket 11 refers to the surface of the pole core 131 that is parallel to the gasket 11. When the pole core 131 is a stacked core, the stacked core can be regarded as a hexahedron, including a top surface, a bottom surface arranged opposite to the top surface, and four side surfaces, wherein the shell 132 corresponding to the top surface of the stacked core is in contact with the air, and the bottom surface and the four side surfaces can be respectively arranged opposite to the gasket 11. When the pole core 131 is a winding core, the winding core is flattened in the radial direction, and the winding core includes two side surfaces with the largest area and arranged oppositely, a top surface and a bottom surface arranged oppositely, and two arcuate side surfaces (the arcuate side surfaces can be regarded as planes), wherein the shell 132 corresponding to the top surface of the winding core is in contact with the air, and the bottom surface and all side surfaces can be arranged opposite to the gasket 11.

[0107] Furthermore, when the two side surfaces with the largest area and arranged opposite to each other are arranged opposite to the gasket 11, the battery restraint tray of the present application can better alleviate the expansion of the battery 13 during the formation process, effectively suppress the occurrence of wrinkles on the electrode of the battery 13 during the charging process, and make the interface between the electrode and the diaphragm in good contact during the entire formation process, thereby improving the formation effect of the battery.

[0108] In the present application, the orthographic projection of the gasket 11 on the surface of the pole core 131 opposite to the gasket 11 refers to the projection formed on the surface of the pole core 131 when the incident light irradiates the gasket 11 in a direction perpendicular to the surface of the pole core 131 opposite to the gasket 11.

[0109] When the outer edge of the orthographic projection of the gasket 11 on the surface is within the edge of the surface, it means that the surface of the gasket 11 is smaller than the surface of the pole core 131. At this time, during the formation process of the battery, the gasket 11 can fully squeeze the pole core 131 in the battery to avoid the bulge of the battery shell 132 from being subjected to force, and can more likely avoid the expansion of the battery and the wrinkles of the pole piece in the pole core 131, thereby improving the electrochemical performance of the battery 13.

[0110] In some embodiments, when the center line of the orthographic projection coincides with the center line of the surface of the pole core 131, when the battery uses a restraint tray to apply a restraint force, the gasket 11 can squeeze the center of the pole core 131, further avoiding excessive expansion of the battery and wrinkling of the pole piece in the pole core 131, so that the battery 13 has better electrochemical performance.

[0111] In some embodiments of the present application, the dimension of the gasket 11 extending in the first direction accounts for 60-90% of the dimension of the surface of the pole core 131 opposite thereto extending in the first direction; and / or,

[0112] The dimension of the gasket 11 extending in the second direction accounts for 60-90% of the dimension of the surface of the pole core 131 opposite thereto extending in the second direction, and the second direction is perpendicular to the first direction.

[0113] The present application does not specifically limit the first direction and the second direction, as long as the first direction is perpendicular to the second direction. In some embodiments, the surface of the pole core is a rectangle, and if the first direction is the length direction of the rectangle, the second direction is the width direction of the rectangle; if the first direction is the width direction of the rectangle, the second direction is the length direction of the rectangle.

[0114] Exemplarily, the dimension of the gasket 11 extending in the first direction may account for 60%, 65%, 70%, 75%, 80%, 82%, 85%, 90% or any two thereof of the dimension of the surface of the pole core 131 opposite thereto extending in the first direction; and / or,

[0115] The dimension of the gasket 11 extending in the second direction may be 60%, 65%, 70%, 75%, 80%, 82%, 85%, 90% or any two thereof of the dimension of the surface of the pole core 131 opposite thereto extending in the second direction.

[0116] In the present application, when the dimension of the gasket 11 extending in the first direction accounts for the dimension of the surface of the pole core 131 arranged opposite to it extending in the first direction, and / or the dimension of the gasket 11 extending in the second direction accounts for the dimension of the surface of the pole core 131 arranged opposite to it extending in the second direction, and when the above relationship is satisfied, the gasket 11 can be used to more fully and directly squeeze the pole core 131 while saving the gasket 11, thereby avoiding excessive deformation of the protrusion of the shell due to squeezing, and at the same time avoiding excessive expansion of the battery 13 during the formation process, avoiding wrinkles in the pole piece, and improving the electrochemical performance of the battery 13.

[0117] Figure 5 A top view of a battery restraint tray in a first embodiment of the present application; Figure 6 A top view of a battery restraint tray in a second embodiment of the present application; Figure 7 FIG. 1 is a top view of a battery restraint tray in the third embodiment of the present application. Figure 5-7 As shown, in some embodiments of the present application, the battery restraint tray further includes an outer frame 12 and a partition 14, wherein the partition 14 is disposed inside the outer frame 12 to divide the outer frame 12 into N battery receiving slots, where N ≥ 2;

[0118] The gasket 11 is disposed on at least a portion of the surface of the partition plate 14 .

[0119] The present application does not impose any particular limitation on the specific shape of the outer frame 12 , as long as it can form a battery receiving slot.

[0120] The present application does not limit the specific shape, location and method of setting of the partition 14, as long as the outer frame can be divided into N battery receiving slots; the present application does not limit the number and size of the partitions 14, and the number and size of the partitions 14 can be selected according to the expected number of battery receiving slots.

[0121] In the present application, the gasket 11 may be disposed on the entire surface of the partition 14 , or the gasket 11 may be disposed on a partial surface of the partition 14 .

[0122] Exemplarily, the outer frame 12 includes two first fixing plates arranged opposite to each other, two second fixing plates arranged opposite to each other, and a base, the two first fixing plates and the two second fixing plates are vertically fixed above the base, the first fixing plates and the second fixing plates are perpendicular to each other, the first fixing plates, the second fixing plates, and the base are surrounded to form a receiving cavity, the partition 14 is arranged in the receiving cavity, and the receiving cavity is divided into N battery receiving slots, and the gasket 11 is arranged on at least a portion of the surface of the partition 14;

[0123] like Figure 5 or Figure 6 As shown, N=4, the battery restraint tray includes three partitions 14, and the three partitions 14 are respectively arranged parallel to a fixed plate of the outer frame 12, and there is a gap between any two partitions 14;

[0124] like Figure 7 As shown, N=6, the battery restraint tray may include three partitions 14, namely a first partition, a second partition and a third partition, wherein the size of the first partition is larger than that of the second partition, the two ends of the first partition are respectively vertically connected to the two first fixing plates of the outer frame 12, the second partition is perpendicular to and passes through the first partition, the two ends of the second partition are respectively vertically connected to the two second fixing plates of the outer frame 12, the third partition is perpendicular to and passes through the first partition, the two ends of the third partition are respectively vertically connected to the two second fixing plates of the outer frame 12, the second partition is parallel to the first partition and there is a gap between them, the second partition can be clamped with the first partition, and the third partition can be clamped with the first partition;

[0125] When N=6, the battery restraint tray may include five partitions 14 , each of which is arranged parallel to a fixing plate of the outer frame 12 , and there is a gap between any two partitions 14 .

[0126] In some embodiments, the battery restraint tray may further include a guide rod and a pressure plate, wherein both ends of the guide rod are respectively vertically connected to the two first fixed plates of the outer frame 12, and L partitions 14 are slidably connected to the guide rods and can slide freely, and a battery receiving groove for placing batteries is formed between adjacent battery partitions 14, wherein a pressure plate is slidably provided on one side of the partition 14.

[0127] The present application does not limit the arrangement of the gasket and the partition. The gasket 11 and the partition 14 may be an integral structure or a separate structure. The gasket 11 and the partition 14 may be bonded together by adhesive or fixed together by screws.

[0128] The present application does not particularly limit the material of the outer frame 12 . In some embodiments, the material of the outer frame 12 may be an aluminum alloy material.

[0129] The present application does not particularly limit the material of the partition 14 . In some embodiments, the material of the partition 14 may be an aluminum alloy material.

[0130] The present application uses a partition 14 to divide the outer frame 12 into N battery accommodating slots, which can realize batch formation of batteries 13 and improve production efficiency.

[0131] like Figure 6 As shown, in some embodiments of the present application, the battery restraint tray further includes an outer frame 12, a partition 14 and a support 15, wherein the partition 14 is disposed inside the outer frame 12 to divide the outer frame 12 into N battery receiving slots, where N ≥ 2;

[0132] The support member 15 is disposed on at least a portion of the surface of the partition 14 , and the gasket 11 is disposed on at least a portion of the surface of the support member 15 away from the partition 14 .

[0133] It can be understood that in some embodiments of the present application, the partition 14, the support member 15 and the gasket 11 are stacked in sequence.

[0134] In the present application, the size of the support member 15 can be selected according to the size of the battery 13, and the support member 15 can be used to adjust the space of the battery receiving slot, so that the battery restraint tray of the present application can be suitable for batteries 13 of more sizes.

[0135] The present application does not impose any particular limitation on the material of the support member 15 , as long as it can adjust the space of the battery receiving slot.

[0136] In the present application, the partition 14, the support member 15 and the gasket 11 may be an integrated structure, or the partition 14, the support member 15 and the gasket 11 may be a separate structure.

[0137] In some embodiments of the present application, the gasket 11 and the support member 15 may be fixed together to obtain a support gasket, and then the support gasket and the partition 14 may be fixed together to achieve the fixation of the partition 14, the support member 15 and the gasket 11. The fixing method of the present application may be adhesive fixing or screw fixing.

[0138] The battery obtained after being formed by the battery restraint tray of the present application can be used as a driving source or energy storage source of electronic equipment, so as to make the electronic equipment perform well in service life and improve the satisfaction of the use of the electronic equipment.

[0139] Among them, electronic devices may include but are not limited to consumer products, vehicles, communication equipment, base stations, etc. Specifically, they may be mobile phones, tablet computers, laptops, ultra-mobile personal computers (ultra-mobile personal computers, UMPCs), handheld computers, walkie-talkies, netbooks, POS machines, personal digital assistants (personal digital assistants, PDAs), wearable devices, virtual reality equipment, base station power supplies, energy storage power stations, new energy vehicles, trams, high-speed rail emergency power supplies, UPS power supplies, flexible wearable devices, and other mobile or fixed terminals with batteries.

[0140] In some embodiments, the electronic device further includes an electrical component, and the battery obtained after the battery restraint tray of the present application is used to provide power for the electrical component. It is understandable that the electronic device may further include a housing, and the electrical component and the battery are located in the housing.

[0141] The solution of the present application is described in detail below through specific embodiments.

[0142] Example 1

[0143] The battery restraint tray of this embodiment includes:

[0144] Outer frame, partitions and gaskets;

[0145] The partition is arranged inside the outer frame, dividing the outer frame into 6 battery receiving slots, the batteries are received in the battery receiving slots, the battery comprises a shell and a pole core, the shell has a pole core receiving cavity, the pole core is received in the pole core receiving cavity, gaskets are respectively arranged between the two outer surfaces of the battery with the largest area and arranged oppositely and the partitions, and the gaskets are embedded in the surface of the partitions;

[0146] The outer shell is an aluminum shell, and the pole core is a winding core;

[0147] The outer edge of the orthographic projection of the gasket on the surface of the pole core opposite to it is located within the edge of the surface of the pole core opposite to it;

[0148] The partition is a 6 series aluminum alloy partition, and the aluminum alloy model is 6061;

[0149] The gasket is a glass fiber gasket, which includes acrylonitrile-butadiene-styrene plastic (ABS) and glass fiber. In the glass fiber gasket, the mass percentage of ABS is 75%, the mass percentage of glass fiber is 25%, and the compression modulus is 400 MPa;

[0150] The surface of the gasket is rectangular, and its corners are rounded;

[0151] The gasket has through holes in the thickness direction. The cross-sectional area of ​​the through holes is circular. The total surface area of ​​the through holes accounts for 40% of the surface area of ​​the gasket. The thickness of the gasket is 4 mm.

[0152] The length direction of the gasket extending in the surface of the pole core opposite to it accounts for 70% of the length of the surface of the pole core opposite to it, and the width direction of the gasket extending in the surface of the pole core opposite to it accounts for 70% of the width of the surface of the pole core opposite to it.

[0153] Comparative Example 1

[0154] The battery restraint tray of this comparative example includes:

[0155] Outer frame, partitions and gaskets;

[0156] The partition is arranged inside the outer frame, dividing the outer frame into 6 battery receiving slots, the batteries are received in the battery receiving slots, the battery comprises a shell and a pole core, the shell has a pole core receiving cavity, the pole core is received in the pole core receiving cavity, gaskets are respectively arranged between the two outer surfaces of the battery with the largest area and arranged oppositely and the partitions, and the gaskets are embedded in the surface of the partitions;

[0157] The outer shell is an aluminum shell, and the pole core is a winding core;

[0158] The outer edge of the orthographic projection of the gasket on the surface of the pole core opposite to it is located within the edge of the surface of the pole core opposite to it;

[0159] The partition is a 6 series aluminum alloy partition, and the aluminum alloy model is 6061;

[0160] The gasket is a silicone gasket, the Shore hardness of the silicone gasket is 45A, and its compression modulus is 15MPa;

[0161] The gasket has through holes in the thickness direction. The cross-sectional area of ​​the through holes is circular. The total surface area of ​​the through holes accounts for 40% of the surface area of ​​the gasket. The thickness of the gasket is 4 mm.

[0162] The length direction of the gasket extending in the surface of the pole core opposite to it accounts for 70% of the length of the surface of the pole core opposite to it, and the width direction of the gasket extending in the surface of the pole core opposite to it accounts for 70% of the width of the surface of the pole core opposite to it.

[0163] Comparative Example 2

[0164] This comparative example used an injection molded tray for a battery.

[0165] Test example

[0166] Preparation of the battery to be formed

[0167] The positive electrode sheet, the separator and the negative electrode sheet are stacked in sequence and then wound to obtain a winding core, which is placed in an aluminum shell. The top cover and the shell of the aluminum shell are welded, and then an airtightness inspection and baking are performed. Then, an electrolyte is injected into the aluminum shell, and a formation nail is inserted. After high-temperature immersion, a battery to be formed is obtained;

[0168] The positive electrode sheet includes an aluminum foil and a positive electrode active layer disposed on two surfaces of the aluminum foil, and the positive electrode active layer includes lithium iron phosphate, a binder PVDF, and a conductive agent SP, wherein the mass ratio of the lithium iron phosphate, the binder, and the conductive agent is 96:1:3;

[0169] The negative electrode sheet includes a copper foil and a negative electrode active layer disposed on two surfaces of the copper foil, wherein the negative electrode active layer includes graphite, a binder CMC and SBR, and a conductive agent SP, wherein the mass ratio of graphite, binder, and conductive agent is 95.4:1.6:1.8:1.2;

[0170] The electrolyte includes LiPF6, EC and DEC, the concentration of LiPF6 is 1 mol / L, and the volume ratio of EC and DEC is 1:1.

[0171] Performance Testing

[0172] 1. Capacity

[0173] The batteries to be formed in the test example are placed in the battery restraint trays in Example 1 and Comparative Example 1, respectively, and the batteries are subjected to formation treatment. A preload of 5000N is applied to the batteries through the battery restraint trays, and the batteries are formed to 60% SOC. After two injections, aging, and sealing pin welding, the batteries are finally divided at 0.2C to obtain the divided capacities of the batteries.

[0174] Figure 8 This is a diagram of the capacity distribution of the batteries after the batteries are formed using a restraint tray in Example 1 and Comparative Example 1 of the present application.

[0175] from Figure 8It can be seen that the battery formed by the battery restraint tray in the embodiment of the present application has a narrower capacity distribution, indicating that the present application can maintain a stable restraint force on the battery during the formation process by arranging a gasket with a high compression modulus on the inner wall of the battery restraint tray, thereby obtaining a battery with high capacity consistency.

[0176] 2. Cycle performance

[0177] The battery to be formed in the test example is placed in the battery restraint tray of Example 1, and the battery is subjected to a formation treatment. A preload of 5000N is applied to the battery through the battery restraint tray, and the battery is formed to 60% SOC. After two injections, aging, sealing pin welding, and capacity separation, a finished battery is obtained;

[0178] The battery to be formed in the test example is placed in the battery injection molding tray in comparative example 2, and the battery is subjected to formation treatment. A preload of 5000N is applied to the battery through the battery injection molding tray, and the battery is formed to 60% SOC. After secondary injection, aging, sealing nail welding, and capacity division, a finished battery is obtained.

[0179] The finished batteries obtained in Example 1 and Comparative Example 2 were disassembled, and the pole pieces in the finished batteries of Example 1 and Comparative Example 2 were obtained respectively, and the morphologies of the pole pieces were observed.

[0180] Fig. 9 This is a morphology diagram of the electrode in the battery after the battery is formed by the restraint tray in Example 1 of the present application; Fig.10 This is a morphology diagram of the electrode in the battery after the battery is formed using the injection molding tray in Comparative Example 2 of the present application.

[0181] from Fig. 9 and Fig.10 It can be seen that compared with the battery formed by the injection molding tray, the battery formed by the restraint tray in the embodiment of the present application has almost no wrinkles on the surface of the electrode, which helps to improve the cycle performance of the battery. This shows that the restraint tray for the battery of the present application can apply a stable restraining force to the battery during the formation process of the battery to avoid wrinkles on the electrode, thereby improving the interface performance of the electrode, allowing the electrode and the diaphragm to fully contact, improving the formation effect of the battery, and can also improve the cycle performance of the battery.

[0182] The finished batteries obtained in Example 1 and Comparative Example 2 were subjected to a cycle performance test, and the cycle performance test specifically includes:

[0183] 1) In an environment of 25°C, discharge the finished battery at a constant current of 0.2C to 2.5V and let it stand for 30 minutes;

[0184] 0.2C CCCV to 3.65V / 0.05C cutoff, let stand for 30min;

[0185] Discharge at 0.2C constant current to 2.5V and let stand for 30min;

[0186] 0.2C CCCV to 3.65V / 0.05C cutoff, let stand for 30min;

[0187] Discharge at 0.2C constant current for 2.5h (50% SOC), and let stand for 30min;

[0188] At 50% SOC, the fixture is installed with an initial preload of 300kgf;

[0189] Discharge at 0.2C constant current to 2.5V, let stand for 30min; leave in 25℃ environment for 4 hours;

[0190] 2) Charge at 1C constant current and constant voltage until the battery is cut off at 3.65V / 0.05C;

[0191] Let stand for 60 minutes; discharge at 1C constant current to 2.5V;

[0192] Let stand for 60 minutes;

[0193] 3) Repeat step 2) to cycle.

[0194] Fig.11 It is a cycle capacity curve diagram of the battery after being formed using the restraint tray for the battery in Example 1 of the present application and the injection molded tray for the battery in Comparative Example 2.

[0195] from Fig.11 It can be seen that the battery formed by the battery restraint tray in the embodiment of the present application has a more excellent cycle performance, which means that the present application can apply a stable restraining force to the electrode core in the battery during the formation process of the battery by arranging a gasket with a high compression modulus on the inner wall of the battery restraint tray, discharge the gas generated by the battery during the formation process, avoid excessive expansion of the battery during the formation process, avoid wrinkles on the electrode sheet, improve the interface performance of the electrode sheet, enable sufficient contact between the electrode sheet and the diaphragm, improve the formation effect of the battery, and thus improve the cycle performance of the battery.

[0196] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery restraint tray, characterized in that: The battery restraint tray has a battery receiving slot, and at least part of the inner wall of the battery receiving slot is provided with a gasket; The compression modulus of the gasket is ≥100 MPa.

2. The battery restraint tray according to claim 1, characterized in that: The gasket is selected from glass fiber gasket, aluminum alloy gasket or stainless steel gasket.

3. The battery restraint tray according to claim 1 or 2, characterized in that: The gasket has a through hole in the thickness direction.

4. The battery restraint tray according to claim 3, characterized in that: The cross-sectional area of ​​the through hole accounts for 30-70% of the surface area of ​​the gasket.

5. The battery restraint tray according to any one of claims 1 to 4, characterized in that: The thickness of the gasket is 1-100 mm.

6. The battery restraint tray according to any one of claims 1 to 5, characterized in that: The battery receiving slot is used to receive a battery, the battery comprising a shell and a pole core, the shell having a pole core receiving cavity, the pole core being received in the pole core receiving cavity, and at least a portion of the outer surface of the shell being disposed adjacent to the gasket; The outer edge of the orthographic projection of the gasket on the surface of the pole core opposite to the gasket is located within the edge of the surface of the pole core opposite to the gasket.

7. The battery restraint tray according to claim 6, characterized in that: The dimension of the gasket extending in the first direction accounts for 60-90% of the dimension of the surface of the pole core arranged opposite thereto extending in the first direction; and / or, The dimension of the gasket extending in the second direction accounts for 60-90% of the dimension of the surface of the pole core arranged opposite thereto extending in the second direction, and the second direction is perpendicular to the first direction.

8. The battery restraint tray according to any one of claims 1 to 7, characterized in that: The corners of the gasket are rounded.

9. The battery restraint tray according to any one of claims 1 to 8, characterized in that: The battery restraint tray further comprises an outer frame and a partition, wherein the partition is arranged inside the outer frame to divide the outer frame into N battery receiving slots, where N≥2; The gasket is arranged on at least a portion of the surface of the partition.

10. The battery restraint tray according to any one of claims 1 to 9, characterized in that: The battery restraint tray further comprises an outer frame, a partition and a support member, wherein the partition is arranged inside the outer frame to divide the outer frame into N battery receiving slots, where N≥2; The support member is arranged on at least a portion of the surface of the partition, and the gasket is arranged on at least a portion of the surface of the support member away from the partition.

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