Reinforced shell and battery

Abstract

The utility model discloses a reinforced shell and a battery, the shell comprises a body and an opening, and the body is used for accommodating a battery cell; the opening is arranged at the end part of the body corresponding to a tab of the battery cell; wherein a ceramic fiber layer is arranged on the inner wall, close to one side of the battery cell, of the body, and the thickness T1 of the ceramic fiber layer and the thickness T2 of a single-layer roll core or a single-layer laminated body of the battery cell meet the condition that T1 is larger than or equal to 0.5 T2 and smaller than or equal to 2.5 T2; the single-layer roll core or the single-layer laminated body comprises a positive pole piece, a negative pole piece and a diaphragm or a solid electrolyte membrane arranged between the positive pole piece and the negative pole piece. Compared with the prior art, the heat resistance of the aluminum alloy is remarkably improved, the mechanical strength of the aluminum alloy is enhanced, the use requirement of a dry-method battery cell can be better met, and the safety and the reliability of a battery are ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a reinforced shell and battery. BACKGROUND

[0002] At present, square battery widely adopts aluminum shell as packing material, this has improved long -term life and reliability of lithium ion battery significantly. However, with the continuous development of dry method technology of lithium electricity industry, dry method electrode is more and more widely used in lithium battery, and the dry method electrode is mixed and fiberized with active material particles, conductive agent and fiberizable binder, and then is obtained by pressing, and no solvent is added in the preparation process, so the active material particles, conductive agent particles etc. of dry method electrode are combined by fiberized binder, and the cohesion is low, a small amount of powder may appear in the process of battery charging and discharging, and the falling particles can easily damage the insulating film on the inner wall of aluminum shell in the process of cell expansion, cause internal short circuit of battery and other problems, especially for dry method negative electrode, when the lithium-containing graphite in the cell interior falls off and contacts with aluminum shell, corrosion and pulverization of aluminum shell will occur, thereby causing leakage. On the other hand, the aluminum alloy material of the existing aluminum shell is soft, and the large monomer capacity cell will deform with the change of the pressure difference between the inside and outside of the cell when applied, which not only increases the difficulty of cell grouping, especially in dry method cell, when the gas production is more, the restraining capacity of aluminum shell needs to be enhanced.

[0003] In addition, the existing aluminum shell also has the following problems: since the melting point of aluminum alloy material is low, when the cell occurs thermal runaway, the temperature is easy to exceed the melting point of aluminum shell, leading to melt-through of aluminum shell, causing harmful substance leakage; the aluminum alloy has good electrical conductivity, when the insulation between the cell and the aluminum shell fails, short circuit may occur, increasing the safety hazard.

[0004] Therefore, the existing pure aluminum alloy aluminum shell needs to be further optimized to meet the reliability requirements of dry method cell. UTILITY MODEL CONTENT

[0005] Therefore, the utility model provides a reinforced shell and battery, better meet the use demand of dry method cell, ensure the safety and reliability of battery. The technical scheme of the utility model is as follows:

[0006] The utility model provides a kind of reinforced shell of battery cell, the shell includes body and opening, the body is used to accommodate the battery cell;The opening is set in the end of the body corresponding to the tab of the battery cell;Wherein, the inner wall of the body near the side of the battery cell is provided with ceramic fiber layer, and the thickness T1 of the ceramic fiber layer and the thickness T2 of single layer roll core or single layer laminated body of the battery cell satisfy, 0.5T2≤T1≤2.5T2;The single layer roll core or single layer laminated body includes positive pole piece, negative pole piece and diaphragm or solid electrolyte membrane set between the positive pole piece and the negative pole piece.

[0007] In some embodiments, the positive tab and the negative tab of the battery cell are located on one side of the battery cell, and the opening is arranged at one end of the body;The body includes two four side walls adjacent to the opening and a bottom surface opposite to the opening;Wherein, the ceramic fiber layer is continuously arranged on the four side walls and the bottom surface, and an overlapping portion is formed on each of the two opposite side walls.

[0008] In some embodiments, the positive tab and the negative tab of the battery cell are located on opposite sides of the battery cell, and the opening is arranged at both ends of the body;The body includes two four side walls adjacent to the opening;Wherein, the ceramic fiber layer is continuously arranged on the four side walls, and an overlapping portion is formed on one of the side walls.

[0009] In some embodiments, the ceramic fiber layer is an alumina fiber layer, a silicon oxide fiber layer, a silicate fiber layer, a zirconium oxide fiber layer, a nitride fiber layer, a carbide fiber layer, or a co-woven fiber layer of at least two of the above.

[0010] In some embodiments, the shell further includes a flexible polymer layer arranged between the body and the ceramic fiber layer;The flexible polymer layer is a polyimide layer, a polyethylene terephthalate layer, a polyvinylidene chloride, or a composite layer of at least two of the above.

[0011] In some embodiments, the diameter of the ceramic fiber in the ceramic fiber layer is 100-1000 nm.

[0012] In some embodiments, the radial compression rate of the ceramic fiber is 10-90%.

[0013] In some embodiments, the aspect ratio of the ceramic fiber is 100-1000.

[0014] In some embodiments, the working temperature of the ceramic fiber layer is 1200-2000℃, and the thickness deformation rate at the working temperature is less than 40%.

[0015] In some embodiments, the ceramic fiber layer has an areal density ranging from 300 g / m2 to 1500 g / m2.

[0016] In some embodiments, the ceramic fiber layer has a mass fraction of inorganic ceramic fibers ranging from 70% to 99.9%.

[0017] In some embodiments, the thickness T2 of a single layer of the winding core or a single layer of the laminate ranges from 200 μm to 600 μm.

[0018] In some embodiments, the thickness T1 of the ceramic fiber layer ranges from 300 μm to 1500 μm.

[0019] The utility model also provides a kind of battery, including any one shell of above embodiment and the electric core being arranged in the shell, the electric core includes positive pole sheet, negative pole sheet and the diaphragm or solid electrolyte membrane being arranged between the positive pole sheet and the negative pole sheet;Wherein, at least one of the positive pole sheet and the negative pole sheet includes fibrous binder.

[0020] The reinforced shell of the utility model is provided with a ceramic fiber layer on the inner wall of the body of the shell near the side of the electric core, and the thickness T1 of the ceramic fiber layer satisfies 0.5T2≤T1≤2.5T2 with the thickness T2 of a single layer of the winding core or a single layer of the laminate of the electric core. While ensuring that the shell has excellent heat resistance and puncture resistance, sufficient restraint force is generated on the electric core, the expansion of the electric core is relieved, and the cycle performance of the battery is improved. The utility model also has the following beneficial effects:

[0021] The ceramic fiber layer of the utility model is a preferred fire-retardant layer, which can form a thermal isolation layer between the heat source and the aluminum alloy layer when the electric core is in thermal runaway, effectively preventing the rapid spread of thermal runaway and improving the safety performance of the battery. At the same time, the ceramic fiber layer has excellent insulation performance, even if the bare electric core itself fails to insulate, the excellent insulation performance of the ceramic fiber layer on the inner surface of the aluminum shell can also prevent internal short circuit between the bare electric core and the aluminum shell, ensuring the electrical safety of the battery.

[0022] Secondly, the ceramic fiber layer has good electrochemical stability, can block the reaction between lithium-containing graphite and aluminum alloy, prevent corrosion and pulverization of the aluminum shell, further improve the durability and safety of the battery, and at the same time, the pressure resistance of the ceramic fiber layer aluminum shell is significantly improved, can withstand higher pressure, prevent deformation and damage of the electric core under high pressure conditions.

[0023] The rigidity of the aluminum shell is significantly increased under the holding of the ceramic fiber layer, and even after a certain number of cycles, the thickness of the square aluminum shell cell can still maintain high consistency. Under the same internal pressure, the degree of aluminum shell bulging is smaller, so the deformation of the aluminum shell is also smaller, the thickness of the cell is maintained, and the structural stability of the battery is improved. In the needle heat runaway test, the aluminum shell will not be broken and can remain intact, thereby avoiding harmful substance leakage and improving the safety of the battery.

[0024] Secondly, due to the excellent deformation recovery performance of the ceramic fiber layer, the verification result of lithium-containing graphite shows that the aluminum shell is not corroded, and the ceramic fiber layer remains intact, which eliminates the occurrence of corrosion reaction and ensures the long-term use performance of the battery. After the un-liquid-filled empty cell is subjected to vibration test and drop test, the insulation withstand voltage impedance is still maintained at a high level, indicating that the ceramic fiber layer significantly improves the mechanical durability and electrical insulation performance of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only an embodiment of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Wherein the same parts are indicated by the same reference numerals. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "bottom surface" and "top surface", "inner" and "outer" refer to the directions towards or away from the geometric center of a particular part.

[0027] Figure 1 It is the overall structure diagram of the battery of the embodiment of the present application;

[0028] Figure 2 It is the cross-sectional view of the reinforcing shell in one direction of the embodiment of the present application;

[0029] Figure 3 It is the structure diagram of the reinforcing shell of the embodiment of the present application;

[0030] Figure 4 It is another cross-sectional view of the embodiment of the present application;

[0031] Figure 5 It is another cross-sectional view of the embodiment of the present application.

[0032] In the above drawings, the meanings of the reference numerals are as follows:

[0033] 1 - housing; 11 - body; 12 - opening; 13 - side wall; 14 - bottom surface;

[0034] 2 - battery cell;

[0035] 3 - ceramic fiber layer; 31 - overlapping portion;

[0036] 41 - positive electrode tab; 42 - negative electrode tab;

[0037] 5 - top cover; 51 - positive electrode post; 52 - negative electrode post. DETAILED DESCRIPTION

[0038] The technical solutions of the present application will be described clearly and completely below in conjunction with the embodiments of the present application and the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specific embodiments are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0040] In the description of the specific embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0041] In the present application, "embodiment" means that the specific features, structures or properties described in conjunction with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments.

[0042] In the description of the embodiments of the utility model, the term "and / or" is only a kind of description of the association relationship of associated object, it indicates that there can be three kinds of relations, for example A and / or B, it can indicate: there is A alone, there are A and B simultaneously, there is B alone these three cases.In addition, the character " / " in the utility model, generally indicates that the front and rear associated objects are a kind of "or" relationship.

[0043] Throughout the utility model, numerical values represent approximate measurements or limits of a range to encompass minor deviations from a given value as well as embodiments having about the value mentioned and embodiments having the exact value mentioned. Except for the working examples provided at the end of the detailed description, all numerical values of parameters such as amounts or conditions in the specification are to be understood as being modified in all instances by the term "about" whether or not "about" actually appears before the numerical value. "About" indicates that the stated numerical value is allowed to vary from the exact value by some minor amount, to a degree that is close in a kind of way; approximately or reasonably close to the stated value; nearly. If the imprecision provided by "about" is not otherwise understood in the art with this ordinary meaning, then "about" as used in the utility model indicates at least the variation that can be produced by ordinary methods of measuring and using such parameters. For example, "about" can include variations less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in certain aspects, optionally less than or equal to 0.1%.

[0044] In addition, the disclosure of ranges includes all values and further partitioned ranges within the entire ranges, including the endpoints and subranges given for the ranges.

[0045] The embodiments of the utility model will be described in more detail below by examples. It should be noted that the embodiments of the utility model are not limited to these examples only.

[0046] At present, square battery widely adopts aluminum shell as packaging material, which significantly improves the long-term life and reliability of lithium ion battery. However, with the continuous development of dry process technology in lithium battery industry, the existing pure aluminum alloy aluminum shell needs to be further optimized to meet the reliability requirements of dry process battery.

[0047] The existing aluminum shell for dry process battery has the following problems:

[0048] The active material particles, conductive agent particles and the like of the dry process electrode are combined by fibrous binder, and the cohesion is low, so a small amount of powder may fall off during the charging and discharging process of the battery, and the falling particles are easy to damage the insulating film on the inner wall of the aluminum shell during the expansion process of the battery cell, causing internal short circuit and other problems of the battery.

[0049] For dry negative, when the lithium-containing graphite inside the battery cell falls off and contacts the aluminum shell, it will cause corrosion and pulverization of the aluminum shell, thereby causing leakage.

[0050] The aluminum alloy material of the existing aluminum shell is soft. When a large monomer capacity battery is applied, it will deform with the change of the internal and external air pressure difference of the battery, which not only increases the difficulty of the battery group, especially in the dry battery, when the gas production is more, the restraining ability of the aluminum shell needs to be enhanced.

[0051] 4. Because the melting point of the aluminum alloy material is relatively low, when the battery cell has thermal runaway, its temperature is easy to exceed the melting point of the aluminum shell, causing the aluminum shell to melt through, causing harmful substances to leak.

[0052] 5. Because the aluminum alloy has good electrical conductivity, when the insulating layer between the battery and the aluminum shell fails, it may cause a short circuit, increasing the safety hazard.

[0053] Therefore, the present application discloses a reinforced shell and a battery for solving the above problems.

[0054] One aspect of the present application provides a reinforced shell 1, in a specific embodiment, as shown in Figures 1-3 A reinforced shell 1 of a battery cell 2 is provided, the shell 1 includes a body 11 for accommodating the battery cell 2 and an opening 12, the opening 12 is provided at the end of the body 11 corresponding to the tab of the battery cell 2.

[0055] In some embodiments, as shown in Figure 1 The positive and negative tabs 41 and 42 of the battery cell 2 can be located on one side of the battery cell 2, and the body 11 has an opening 12 corresponding to the side of the battery cell 2 where the positive and negative tabs 41 and 42 are located, so that the positive and negative tabs 41 and 42 can be respectively connected to the positive and negative poles 51 and 52 of the top cover 5.

[0056] Alternatively, in other embodiments, the positive and negative tabs 41 and 42 of the battery cell 2 can be located on different sides of the battery cell 2, for example, on opposite sides of the battery cell 2, and the body 11 has openings 12 corresponding to the opposite sides of the battery cell 2 where the tabs are located, i.e. openings 12 are provided at the opposite ends of the body 11 as shown in Figure 3 So that the positive and negative tabs 41 and 42 can be respectively connected to the positive and negative poles 51 and 52 of the top cover 5, and the two-side tab battery structure is the prior art in the art, which will not be described here.

[0057] Wherein, the inner wall of the body 11 near one side of the battery cell 2 is provided with a ceramic fiber layer 3, as shown in Figure 2As shown, the thickness T1 of the ceramic fiber layer 3 and the thickness T2 of the single-layer core or single-layer laminate of the cell 2 satisfy 0.5T2≤T1≤2.5T2; the single-layer core or single-layer laminate consists of a positive electrode, a negative electrode, and a separator or solid electrolyte membrane disposed between the positive electrode and the negative electrode.

[0058] The reinforced casing is reinforced by providing a ceramic fiber layer 3 on the inner wall of the body 11 of the casing 1 near the cell 2, and the thickness T1 of the ceramic fiber layer 3 satisfies the same condition as the thickness T2 of the single-layer wound core or single-layer laminate of the cell: 0.5T2≤T1≤2.5T2. While ensuring that the casing 1 has excellent heat resistance and puncture resistance, it provides sufficient constraint force to the cell 2, alleviates the expansion of the cell, and improves the cycle performance of the battery.

[0059] In some embodiments, the positive electrode tab 41 and the negative electrode tab 42 of the battery cell 2 are located on one side of the battery cell 2, and the opening 12 is located at one end of the body 11, such as... Figure 1 As shown; the body 11 includes two or four side walls 13 adjacent to the opening 12 and a bottom surface 14 opposite to the opening 12; wherein, the ceramic fiber layer 3 is continuously disposed on the four side walls 13 and the bottom surface 14, and overlapping portions 31 are formed on the two opposite side walls 12 respectively.

[0060] In some implementations, such as Figure 3 As shown, the positive electrode tab 41 and the negative electrode tab 42 of the battery cell 2 are located on opposite sides of the battery cell 2, and the opening 12 is provided at both ends of the body 11; the body 11 includes two or four side walls 13 adjacent to the opening 12; wherein, the ceramic fiber layer 3 is continuously disposed on the four side walls 13, and an overlapping portion 31 is formed on one of the side walls 13.

[0061] In some embodiments, the ceramic fiber layer 3 is an alumina fiber layer, a silicon oxide fiber layer, a silicate fiber layer, a zirconium oxide fiber layer, a nitride fiber layer, a carbide fiber layer, or a co-woven fiber layer of at least two of these.

[0062] The ceramic fiber layer 3 of this application can be obtained by weaving one of the above-mentioned individual alumina fibers, silicon oxide fibers, silicate fibers, zirconium oxide fibers, nitride fibers, and carbide fibers. It can also be obtained by weaving two or more of the above-mentioned fibers together. This application does not impose any restrictions.

[0063] The ceramic fiber layer 3 of this invention is obtained by weaving corresponding inorganic ceramic fibers. Specifically, inorganic ceramic fibers can be obtained by methods such as melting, sol-gel, impregnation, slurry, and electrospinning.

[0064] Among them, the melting method is to melt the inorganic oxide by electric heating to form a melt, and then the melt is formed into corresponding nanofiber by different fiber forming methods. The sol-gel method prepares a solution of raw materials to form a sol, and the sol is formed into the required fiber by different fiber forming techniques, and finally the gel fiber is formed into ceramic fiber by heat treatment. The substrate fiber of the impregnation method is selected from hydrophilic viscose fibers, the substrate fiber is fully immersed in the impregnation solution, and then the impregnated substrate fiber is dried, sintered, woven and other processes to obtain corresponding inorganic fibers. The slurry method, also known as the Dupont method, disperses inorganic powder in water, and also needs to add dispersing agent, rheological additive, sintering additive and other additives in water to prepare uniform slurry. The slurry is then extruded into fibers, dried, sintered and other processes to obtain corresponding fibers. The electrospinning method is a classic preparation method, which can be used to prepare high-purity inorganic fibers with a fiber diameter of about 150 nm by combining electrospinning with high-temperature calcination.

[0065] In some embodiments, the silicate fiber layer can be an aluminum silicate fiber layer, which is obtained by spinning lithium silicate fiber; the ceramic fiber of the nitride fiber layer is selected from silicon nitride fiber Si3N4, and the ceramic fiber of the carbide fiber layer is selected from silicon carbide ceramic fiber SiC, but not limited thereto.

[0066] In some embodiments, the shell 1 further comprises a flexible polymer layer (not shown in the figure) disposed between the body 11 and the ceramic fiber layer 3; the flexible polymer layer is a polyimide layer, a polyethylene terephthalate layer, a polyvinylidene chloride, or a composite layer of at least two of them. The flexible polymer layer can provide sufficient adhesion between the ceramic fiber layer 3 and the side wall 13 and the bottom surface 14 of the body 11, ensuring the stable adhesion of the ceramic fiber layer 3.

[0067] In some embodiments, the diameter of the ceramic fiber in the ceramic fiber layer 3 is 100-1000 nm, so that the ceramic fiber layer 3 has sufficient mechanical strength to constrain the expansion of the battery cell 2.

[0068] In some embodiments, the radial compression rate of the ceramic fiber is 10%-90%, when the positive or negative electrode sheet of the battery cell 2 is dropped or the expansion of the battery cell 2 extrudes the ceramic fiber layer 3, etc., the ceramic fiber layer 3 can maintain high retractability, reduce the risk of being pierced, and avoid causing short circuit.

[0069] In some embodiments, the aspect ratio of the ceramic fiber is 100-1000, and within the above aspect ratio range, the ceramic fiber layer 3 achieves excellent mechanical strength and flexibility.

[0070] In some embodiments, the ceramic fiber layer 3 operates at a temperature of 1200℃-2000℃, and its thickness deformation rate at the operating temperature is less than 40%, thereby ensuring that the cell 2 will not explode in the event of thermal runaway and ensuring the safety of the battery.

[0071] In some embodiments, the areal density of the ceramic fiber layer 3 ranges from 300 g / m² to 1500 g / m²;

[0072] In some embodiments, the inorganic ceramic fibers in the ceramic fiber layer 3 account for 70%-99.9% of the total mass.

[0073] With the above-mentioned areal density and inorganic ceramic fiber mass ratio, the ceramic fiber layer 3 can maintain excellent mechanical strength and flexibility, thereby ensuring the stability and safety of the battery.

[0074] In some embodiments, the thickness T2 of a single layer of the core or a single layer of the laminate is 200 μm-600 μm;

[0075] In some embodiments, the thickness T1 of the ceramic fiber layer 3 is between 300 μm and 1500 μm. This thickness of the ceramic fiber layer 3 ensures sufficient rigidity, toughness, and retraction without significantly increasing the thickness of the casing 1, thereby maintaining the energy density of the battery.

[0076] This utility model also provides a battery, such as Figure 1 As shown, in some embodiments of this utility model, the battery includes a casing 1 and a battery cell 2 disposed within the casing 1. The casing 1 includes a body 11 and an opening 12. The body 11 is used to accommodate the battery cell 2; the opening 12 is disposed at the end of the body 11 corresponding to the tabs of the battery cell 2; wherein, a ceramic fiber layer 3 is disposed on the inner wall of the body 11 near the battery cell 2, such as... Figure 2 As shown, the thickness T1 of the ceramic fiber layer 3 and the thickness T2 of the single-layer core or single-layer stack of the battery cell 2 satisfy the condition 0.5T2≤T1≤2.5T2.

[0077] In some implementations, such as Figure 1 As shown, the positive electrode tab 41 and the negative electrode tab 42 of the battery cell 2 can be located on one side of the battery cell 2. The body 11 corresponds to the opening 12 on the side of the battery cell 2 where the positive electrode tab 41 and the negative electrode tab 42 are provided, so that the positive electrode tab 41 and the negative electrode tab 42 can be electrically connected to the positive electrode post 51 and the negative electrode post 52 on the top cover 5, respectively.

[0078] Alternatively, in other embodiments, the positive tab 41 and the negative tab 42 of the battery cell 2 can be located on different sides of the battery cell 2, for example, on opposite sides of the battery cell 2, and the body 11 is provided with openings 12 corresponding to the opposite sides of the battery cell 2 provided with the tabs, i.e. openings 12 are provided at opposite ends of the body 11 as shown in Figure 3 The two-side tab battery cell structure is prior art in the field, and will not be described here.

[0079] The battery cell 2 comprises a positive electrode sheet, a negative electrode sheet, and a separator or a solid electrolyte film arranged between the positive electrode sheet and the negative electrode sheet; at least one of the positive electrode sheet and the negative electrode sheet comprises a fibrous binder.

[0080] In the embodiment, at least one of the positive electrode sheet and the negative electrode sheet is obtained by dry method.

[0081] In some embodiments, the positive electrode sheet is obtained by mixing positive active material particles, a positive conductive agent, and a positive binder, then performing fiberization, and then rolling the fiberized mixture by a compression roller.

[0082] In some embodiments, the negative electrode sheet is obtained by mixing negative active material particles, a negative conductive agent, and a negative binder, then performing fiberization, and then rolling the fiberized mixture by a compression roller.

[0083] In some embodiments, the solid electrolyte film can also be obtained by dry method, i.e. mixing inorganic solid electrolyte particles or polymer electrolyte particles with a fibrous binder and performing fiberization, and then rolling the fiberized mixture by a compression roller.

[0084] The reinforced shell is provided with a ceramic fiber layer 3 on the inner wall of the body 11 of the shell 1 on the side close to the battery cell 2, and the thickness T1 of the ceramic fiber layer 3 and the thickness T2 of the single-layer winding core or the single-layer laminated body of the battery cell satisfy 0.5T2≤T1≤2.5T2; while ensuring excellent heat resistance and puncture resistance of the shell 1, sufficient constraint force is generated on the battery cell 2, the expansion of the battery cell is alleviated, and the cycle performance of the battery is improved.

[0085] The utility model also has the following beneficial effects:

[0086] The ceramic fiber layer 3 is a preferable fireproof layer, can form a thermal isolation layer between a heat source and an aluminum alloy layer when the electric core 2 is in thermal runaway, effectively prevents rapid spread of thermal runaway, and improves safety performance of the battery.

[0087] Secondly, the ceramic fiber layer 3 has good electrochemical stability, can block the reaction between lithium-containing graphite and aluminum alloy, prevents corrosion and pulverization of the aluminum shell, further improves durability and safety of the battery, and meanwhile, the pressure resistance of the aluminum shell with the ceramic fiber layer 3 is significantly improved, can withstand higher pressure, prevents deformation and damage of the electric core under high pressure conditions.

[0088] The aluminum shell in the utility model has significantly increased rigidity under the support of the ceramic fiber layer 3, and even after a certain number of cycles, the thickness of the square aluminum shell electric core can still maintain high consistency. Under the same internal pressure, the aluminum shell is less swollen, and therefore, the deformation of the aluminum shell is also small, the thickness of the electric core 2 is maintained, and the structural stability of the battery is improved. In the needle heat runaway test, the aluminum shell does not break and can remain intact, thereby avoiding leakage of harmful substances and improving the safety of the battery.

[0089] Secondly, since the ceramic fiber layer 3 has excellent deformation recovery performance, the verification result of lithium-containing graphite shows that the aluminum shell is not corroded, and the ceramic fiber layer 3 remains intact, eliminates the occurrence of corrosion reaction, ensures long-term use performance of the battery, and the insulation voltage resistance impedance of the un-liquid-filled empty electric core still maintains a high level after vibration test and drop test, indicating that the ceramic fiber layer 3 significantly improves the mechanical durability and electrical insulation performance of the battery.

[0090] It should be pointed out that the above only describes preferred embodiments of the utility model and does not limit the utility model, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A reinforced casing for an electrical cell, characterized in that, The shell comprises a body for accommodating the battery cell and an opening corresponding to the tab of the battery cell arranged at the end of the body; wherein a ceramic fiber layer is arranged on the inner wall of the body near the side of the battery cell, and the thickness T1 of the ceramic fiber layer and the thickness T2 of the single-layer wound core or single-layer laminated body of the battery cell satisfy 0.5T2≤T1≤2.5T2; the single-layer wound core or single-layer laminated body comprises a positive electrode sheet, a negative electrode sheet, and a separator or a solid-state electrolyte membrane arranged between the positive electrode sheet and the negative electrode sheet.

2. The reinforced shell of claim 1, wherein, The positive and negative tabs of the battery cell are located on one side of the battery cell, and the opening is arranged at one end of the body; the body comprises two or four side walls adjacent to the opening and a bottom surface opposite to the opening; wherein the ceramic fiber layer is continuously arranged on the four side walls and the bottom surface, and an overlapping part is formed on each of the two opposite side walls.

3. The reinforced shell according to claim 1, wherein, The positive and negative tabs of the battery cell are located on opposite sides of the battery cell, and the opening is arranged at both ends of the body; the body comprises two or four side walls adjacent to the opening; wherein the ceramic fiber layer is continuously arranged on the four side walls, and an overlapping part is formed on one of the side walls.

4. The reinforced shell according to claim 1, wherein, The ceramic fiber layer is an alumina fiber layer, a silica fiber layer, a silicate fiber layer, a zirconia fiber layer, a nitride fiber layer, a carbide fiber layer, or a co-woven fiber layer of at least two of them.

5. The reinforced shell according to claim 1, wherein, The shell further comprises a flexible polymer layer arranged between the body and the ceramic fiber layer; the flexible polymer layer is a polyimide layer, a polyethylene terephthalate layer, a polyvinylidene chloride layer, or a composite layer of at least two of them.

6. The reinforced shell of claim 1, wherein, In the ceramic fiber layer, the diameter of the ceramic fiber is 100-1000 nm, the radial compression rate is 10%-90%, and the aspect ratio is 100-1000.

7. The reinforced shell of claim 1, wherein, The working temperature of the ceramic fiber layer is 1200-2000℃, and the thickness deformation rate at the working temperature is less than 40%.

8. The reinforced shell of claim 1, wherein, The areal density of the ceramic fiber layer ranges from 300g / m² to 1500g / m².

9. The reinforced shell of claim 1, wherein, The thickness T2 of the single-layer wound core or single-layer laminated body is 200-600μm; the thickness T1 of the ceramic fiber layer is between 300μm and 1500μm.

10. A battery, characterized by The shell comprises a body for accommodating the battery cell and an opening corresponding to the tab of the battery cell arranged at the end of the body; wherein a ceramic fiber layer is arranged on the inner wall of the body near the side of the battery cell, and the thickness T1 of the ceramic fiber layer and the thickness T2 of the single-layer wound core or single-layer laminated body of the battery cell satisfy 0.5T2≤T1≤2.5T2; the single-layer wound core or single-layer laminated body comprises a positive electrode sheet, a negative electrode sheet, and a separator or a solid-state electrolyte membrane arranged between the positive electrode sheet and the negative electrode sheet.

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