Solid-state battery and processing system thereof

Abstract

The utility model provides a solid-state battery and a processing system thereof, and belongs to the technical field of batteries, the solid-state battery comprises a positive plate, an electrolyte membrane and a negative plate, the electrolyte membrane comprises a main body part and an extension part, a first concave surface and a second concave surface are formed on the main body part, and the first concave surface and the second concave surface are respectively attached to one side of the positive plate or the negative plate in the first direction; the extension part comprises a first extension part and a second extension part which are oppositely arranged; and the first extension part and the second extension part respectively coat one side of the positive plate and one side of the negative plate in the second direction. The solid-state battery and the processing system thereof provided by the utility model solve the problems of edge micro short circuit and the like caused by stress concentration of the solid-state battery.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a kind of solid-state battery and its processing system. BACKGROUND

[0002] As the next generation of energy storage devices, solid-state batteries have become an important direction for future battery technology development due to their high energy density, safety and long life. However, the shear resistance of all-solid-state batteries, especially sulfide electrolyte membranes, is poor, and the traditional laminated structure is prone to micro-short circuit at the edge of high-capacity batteries, which reduces the reliability and safety of solid-state batteries. SUMMARY

[0003] The utility model provides a kind of solid-state battery and its processing system, can solve the problem such as edge micro-short circuit caused by stress concentration in solid-state battery preparation process.

[0004] In a first aspect, the utility model provides a kind of solid-state battery, comprising: positive sheet, electrolyte membrane and negative sheet;The electrolyte membrane includes main part and extension part, the main part is formed with first concave surface and second concave surface, the first concave surface, the second concave surface respectively adhere to one side of the positive sheet or the negative sheet in the first direction, the extension part includes oppositely arranged first extension part and second extension part, the first extension part, second extension part respectively adhere to one side of the positive sheet and the negative sheet in the second direction, the first direction and the second direction are perpendicular to each other.

[0005] Preferably, the electrolyte membrane, the positive sheet, the negative sheet are all arranged in axial symmetry.

[0006] Preferably, the main part of the electrolyte membrane includes first part and second part, in the first direction, the thickness of the first part is greater than the thickness of the second part;In the second direction, the width of the second part of the main part of the electrolyte membrane accounts for 90~99% of the total width of the whole main part.

[0007] Preferably, the main part of the electrolyte membrane includes first part and second part, in the first direction, the thickness of the first part and the second part is 3~10 μm, and along the first direction, the main part of the electrolyte membrane presents gradually increasing thickness from the center of the second part to the first part.

[0008] Preferably, the positive sheet includes third part and fourth part, in the first direction, the thickness of the third part is less than the thickness of the fourth part, and the extension part of the electrolyte membrane adheres to the side wall of the third part of the positive sheet.

[0009] Preferably, the negative electrode sheet includes a fifth portion and a sixth portion, in the first direction, the thickness of the fifth portion is smaller than the thickness of the sixth portion, and the extension portion of the electrolyte film is attached to the sidewall of the fifth portion of the negative electrode sheet.

[0010] Preferably, in the second direction, the width of the first extension portion and the second extension portion of the extension portion of the electrolyte film is 10-50 microns; in the first direction, the thickness of the extension portion of the electrolyte film is the same as the sum of the thickness of the positive electrode sheet, the thickness of the main portion of the electrolyte film and the thickness of the negative electrode sheet.

[0011] Preferably, the thickness of the positive electrode sheet is the same as the thickness of the negative electrode sheet, in the first direction, the thickness of the extension portion of the electrolyte film is the same as the sum of the thickness of the positive electrode sheet, the thickness of the main portion of the electrolyte film and the thickness of the negative electrode sheet;

[0012] In the second direction, the width of the positive electrode sheet is the same as the width of the negative electrode sheet; the width of the electrolyte film is the same as the sum of the width of the positive electrode sheet, the width of the first extension portion and the width of the second extension portion.

[0013] Preferably, the thickness of the positive electrode sheet is not the same as the thickness of the negative electrode sheet, in the first direction, the thickness of the extension portion of the electrolyte film is the same as the sum of the thickness of the positive electrode sheet, the thickness of the main portion of the electrolyte film and the thickness of the negative electrode sheet;

[0014] In the second direction, the width of the positive electrode sheet is the same as the width of the negative electrode sheet; the width of the electrolyte film is the same as the sum of the width of the positive electrode sheet, the width of the first extension portion and the width of the second extension portion.

[0015] In the second aspect, the utility model also provides a processing system of the foregoing solid-state battery, which comprises: an electrolyte film processing device, a positive electrode processing device, a negative electrode processing device, an oven, an isostatic press;

[0016] The electrolyte film processing device is used for preparing the electrolyte film of the solid-state battery.

[0017] The positive electrode processing device is used for preparing the positive electrode sheet of the solid-state battery.

[0018] The negative electrode processing device is used for preparing the negative electrode sheet of the solid-state battery.

[0019] The oven is used for drying the electrolyte film, the positive electrode sheet and the negative electrode sheet.

[0020] The isostatic press is used for heat isostatic pressing of the positive electrode sheet, the electrolyte film and the negative electrode sheet which are stacked after drying to obtain the solid-state battery;

[0021] The electrolyte film processing device comprises a coating tool head and a coating base, the coating tool head is provided with a scraper body, the center area of the scraper body is provided with a first protruding part, and the scraper body is symmetrically distributed; the center area of the coating base is provided with a second protruding part; the first protruding part and the second protruding part are both in a structure of thick in the middle and thin on both sides for the electrolyte film; the first protruding part is used for forming a first concave surface of a main body part of the electrolyte film, and the second protruding part is used for forming a second concave surface of the main body part of the electrolyte film.

[0022] Preferably, the first protruding part is the same as the second protruding part.

[0023] Preferably, the height of the first protruding part gradually decreases from the middle to both sides, and the height of the second protruding part gradually decreases from the middle to both sides.

[0024] Preferably, the oven is provided with a plurality of infrared lamps, and when the electrolyte film is placed in the oven, the infrared lamps are correspondingly arranged above the first part of the main body part of the electrolyte film.

[0025] Compared with the prior art, the solid-state battery has at least the following beneficial effects:

[0026] The solid-state battery provided by the utility model, through thickening the edge of the electrolyte film and adopting the electrolyte film to semi-cover the positive electrode sheet and the negative electrode sheet, significantly reduces the concentration effect of stress on the edge of the electrolyte film, improves the mechanical strength of the edge of the battery, reduces the generation of edge cracks, simultaneously effectively avoids the short circuit phenomenon existing in the battery lamination.

[0027] Meanwhile, the processing system of the solid-state battery provided by the utility model can prepare the electrolyte film which is thickened on the edge and can semi-cover the positive electrode sheet and the negative electrode sheet, and then the solid-state battery assembled by the electrolyte film and the positive electrode sheet and the negative electrode sheet can avoid the short circuit phenomenon in the battery lamination preparation, improve the safety performance of the battery, and is compatible with various electrolytes and electrode materials, and has wide applicability. BRIEF DESCRIPTION OF DRAWINGS

[0028] 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 embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 is a structural diagram of a solid-state battery provided by the present application;

[0030] Figure 2 is a structural diagram of an electrolyte membrane provided by the present application;

[0031] Figure 3 is a structural diagram of a coating substrate and a scraper body provided by the present application;

[0032] Figure 4 is a structural diagram of a solid-state battery provided by the comparative example 1;

[0033] Figure 5 is a structural diagram of a solid-state battery provided by the comparative example 2;

[0034] Reference signs: 10-positive electrode sheet; 20-electrolyte membrane; 30-negative electrode sheet; 201-main body part; 202-extension part; 2021-first extension part; 2022-second extension part; 2011-first part; 2012-second part; 401-coating substrate; 402-scraper body; 4021-first protruding part; 4011-second protruding part. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical scheme in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0036] As Figure 1As shown, this utility model provides a solid-state battery, which includes: a positive electrode 10, an electrolyte membrane 20, and a negative electrode 30; the electrolyte membrane includes a main body portion 201 and an extension portion 202, the main body portion 201 is formed with a first concave surface and a second concave surface, the first concave surface and the second concave surface are respectively attached to one side of the positive electrode 10 or the negative electrode 30 in a first direction, the extension portion 202 includes a first extension portion 2021 and a second extension portion 2022 disposed opposite to each other, and the first extension portion 2021 and the second extension portion 2022 respectively cover one side of the positive electrode 10 and the negative electrode 30 in a second direction, and the first direction and the second direction are perpendicular to each other.

[0037] It should be noted that the first direction is as follows: Figure 1 The vertical direction (Y direction) shown is the thickness direction of the electrolyte film in the solid-state battery; the second direction is as follows: Figure 1 The horizontal direction shown is the width direction (X direction) of the electrolyte membrane in the solid-state battery. The first direction and the second direction are perpendicular to each other.

[0038] In this utility model, such as Figure 1 As shown, the electrolyte membrane is similar to an H-shape. Therefore, the first and second concave surfaces of its main body can adhere to the positive and negative electrode sheets, and the extended part can adhere to and partially cover the positive and negative electrode sheets. This can directly avoid the short circuit phenomenon caused by the contact between the positive and negative electrode sheets of traditional stacked solid-state batteries.

[0039] In some preferred embodiments, the electrolyte membrane, positive electrode, and negative electrode are all arranged in an axisymmetric manner.

[0040] In some preferred embodiments, such as Figure 2 As shown, the main body portion 201 of the electrolyte membrane 20 includes a first portion 2011 and a second portion 2012. In a first direction, the thickness of the first portion 2011 is greater than the thickness of the second portion 2012. In a second direction, the width of the second portion 2012 of the main body portion 201 of the electrolyte membrane 20 accounts for 90 to 99% of the total width of the entire main body portion 201 (for example, it can be 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5% or 99%).

[0041] In this invention, by designing the thickness of the second part of the main body of the electrolyte membrane to be less than the thickness of the first part, the electrolyte membrane is thicker at the edges and thinner in the middle, thereby reducing the stress concentration effect at the edge of the electrolyte membrane, improving the mechanical strength of the battery edge, and reducing the phenomenon of edge cracking.

[0042] In the utility model, the positive plate and the negative plate which are embedded with the electrolyte film are all the structure of thin edge and thick middle, the expansion stress is reduced through the edge thinning design of the positive plate and the negative plate, the dropping and pulverization phenomenon caused by the expansion and shrinkage of the electrode material in the positive plate and the negative plate is prevented, and the long-term stability of the solid-state battery is improved.

[0043] In the utility model, through limiting in the first direction, the width of the second part of the main part of the electrolyte film accounts for 90~99% of the total width of the whole main part, the thickening area of the electrolyte film is controlled in the area of 1~10% of the edge of the electrolyte film, the mechanical strength and the shear resistance of the edge can be enhanced, and the crack or local damage caused by the volume expansion in the charging and discharging process can be prevented.For example, the first part of the electrolyte film which is thickened accounts for 5% of the main part, and in the width direction of the main part of the electrolyte film, the structure is 5% first part / 90% second part / 5% first part, and the thickness of the second part is less than the thickness of the first part.

[0044] In the utility model, since the edge thickness of the electrolyte film is thickened, the contact area of the positive plate, the negative plate and the electrolyte film is increased, the interface combination effect is improved, and the poor contact problem in the charging and discharging process is inhibited; meanwhile, the larger interface contact area enhances the ion transmission efficiency of the battery, and the battery rate performance can be further improved.

[0045] In some preferred embodiments, as shown in Figure 2 The main part 201 of the electrolyte film 20 includes a first part 2011 and a second part 2012, and in the first direction, the difference between the thicknesses of the first part 2011 and the second part 2012 is 3~10 μm (for example, it can be 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm or 10 μm), and along the first direction, the main part 201 of the electrolyte film gradually increases in thickness from the center of the second part 2012 to the first part 2011.

[0046] In the utility model, in order to make the edge thickening design of electrolyte membrane can give full play to its function, therefore limit the thickness difference of the first part and the second part of the main part of electrolyte membrane 3~10 μm.If the thickness difference is less than 3 μm, on the one hand, the shear resistance is insufficient, the effect of edge thickening is limited, it is difficult to effectively disperse the stress concentrated in the edge in the process of charging and discharging, leading to the electrolyte membrane edge still prone to crack or micro short circuit problem;On the other hand, the mechanical strength is insufficient, the edge thickening is insufficient to significantly improve the mechanical damage resistance of the edge, also can reduce the overall durability and safety of battery.If the thickness difference is greater than 10 μm, on the one hand, due to the edge thickness is too large, it can cause uneven stress distribution between electrolyte membrane and positive and negative pole piece, especially in the pressing and running process, the interface between the edge and the main part is prone to separation;On the other hand, the thickness of the edge region is too large, which can hinder the uniform transmission of ions in the electrolyte, thereby affecting the electrochemical performance of the all-solid-state battery.At the same time, the edge is too thick, which can cause material flowability problem in the coating and drying process, affect the coating precision and uniformity, and increase the manufacturing cost.

[0047] In some preferred embodiments, the positive pole piece includes a third part and a fourth part, in the first direction, the thickness of the third part is less than the thickness of the fourth part, and the extension part of the electrolyte membrane is attached to the side wall of the third part of the positive pole piece.

[0048] In some preferred embodiments, the negative pole piece includes a fifth part and a sixth part, in the first direction, the thickness of the fifth part is less than the thickness of the sixth part, and the extension part of the electrolyte membrane is attached to the side wall of the fifth part of the negative pole piece.

[0049] In some preferred embodiments, as shown in Figure 1 , Figure 2 In the second direction, the width of the first extension 2021 and the second extension 2022 of the extension part 202 of the electrolyte membrane 20 is 10~50 μm (for example, it can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm);In the first direction, the thickness of the extension part 202 of the electrolyte membrane 20 is the same as the sum of the thickness of the positive pole piece 10, the thickness of the main part 201 of the electrolyte membrane 20 and the thickness of the negative pole piece 30.

[0050] It should be noted that in the second direction, the width of the main part of the electrolyte membrane is the same as the width of the positive pole piece and the negative pole piece, the first extension and the second extension extending out from the left and right sides of the electrolyte membrane are used to semi-cover the positive pole piece and the negative pole piece, the width of the extension part on the left and right sides is the same, that is, the left side extends 10~50 μm, the right side extends 10~50 μm, and the thickness of the extension part is the same as the sum of the thickness of the positive pole piece, the negative pole piece and the main part of the electrolyte membrane (for example,Figure 1 For example, if the difference between the width of the electrolyte film and the width of the positive electrode sheet is 20 μm, the electrolyte film extends 10 μm on each of the left and right sides; for example, if the difference between the width of the electrolyte film and the width of the positive electrode sheet is 100 μm, the electrolyte film extends 50 μm on each of the left and right sides. Among them, as shown in Figure 2 , d 1 is the width of the first extension or the second extension, d 1∈[10μm,50μm]; d 2 is the width of the main body part of the electrolyte film, d 2 is the same as the width of the positive electrode sheet and the negative electrode sheet.

[0051] In the utility model, in order to make electrolyte film can form first concave surface and second concave surface, to form half package to positive electrode sheet, negative electrode sheet, avoid the width of electrolyte film in second direction too short and lead to extension part width is shorter, in traditional lamination process, it is easy to cause the gap or opening of both sides package position, also in order to avoid the width of electrolyte film too long and lead to extension part width is longer, and cause battery size is too big, further limit its application scene, therefore limit the width of first extension, second extension all is 10~50 μm.

[0052] In some preferred embodiments, the thickness of the positive electrode sheet is the same as the thickness of the negative electrode sheet, and in the first direction, the thickness of the extension part of the electrolyte film is the same as the sum of the thickness of the positive electrode sheet, the thickness of the main body part of the electrolyte film and the thickness of the negative electrode sheet.

[0053] In the second direction, the width of the positive electrode sheet is the same as the width of the negative electrode sheet, and the width of the electrolyte film is the same as the sum of the width of the positive electrode sheet, the width of the first extension and the width of the second extension.

[0054] In some preferred embodiments, the thickness of the positive electrode sheet is not the same as the thickness of the negative electrode sheet, and in the first direction, the thickness of the extension part of the electrolyte film is the same as the sum of the thickness of the positive electrode sheet, the thickness of the main body part of the electrolyte film and the thickness of the negative electrode sheet.

[0055] In the second direction, the width of the positive electrode sheet is the same as the width of the negative electrode sheet, and the width of the electrolyte film is the same as the sum of the width of the positive electrode sheet, the width of the first extension and the width of the second extension.

[0056] The utility model also provides a processing system of the foregoing solid-state battery, which comprises: an electrolyte film processing device, a positive electrode processing device, a negative electrode processing device, an oven, an isostatic press;

[0057] The electrolyte film processing device is used to prepare the electrolyte film of the solid-state battery.

[0058] The positive electrode processing device is used to prepare the positive electrode sheet of the solid-state battery.

[0059] The negative electrode processing device is used for preparing a negative electrode sheet of the solid-state battery;

[0060] The oven is used for drying the electrolyte film, the positive electrode sheet and the negative electrode sheet;

[0061] The isostatic press is used for heat isostatic pressing the positive electrode sheet, the electrolyte film and the negative electrode sheet which are stacked and placed after drying to obtain the solid-state battery;

[0062] As shown in Figure 3 The electrolyte film processing device comprises a coating tool bit and a coating base 401; the coating tool bit is provided with a scraper body 402, the central region of the scraper body 402 is provided with a first protruding part 4021, and the scraper body is symmetrically distributed; the central region of the coating base is provided with a second protruding part 4011; the first protruding part 4021 and the second protruding part 4011 both have a structure of thick in the middle and thin on both sides; the first protruding part 4021 is used for forming a first concave surface of the main body part of the electrolyte film of the solid-state battery, and the second protruding part 4011 is used for forming a second concave surface of the main body part of the electrolyte film of the solid-state battery.

[0063] In the utility model, since the electrolyte film is provided with two concave surfaces, the thickness of the middle region of the main body part of the electrolyte film is lower than the thickness of the edge region, therefore the conventional coating tool bit and the coating base cannot obtain the electrolyte film with the structure, and therefore it is necessary to design a special scraper body and a coating base according to the structure of the electrolyte film to obtain the electrolyte film by cooperation of the scraper body and the coating base.

[0064] In the utility model, the proportion of the edge region of the first protruding part and the second protruding part can be further limited according to the structure of the electrolyte film to prepare the required electrolyte film, and the electrolyte film is adapted to and coated with the prepared positive electrode sheet and negative electrode sheet.

[0065] In the utility model, the electrolyte film as shown in Figure 1 can be prepared by using the electrolyte film processing device first, then the positive electrode sheet and the negative electrode sheet as shown in Figure 1 can be prepared by using the positive electrode processing device and the negative electrode processing device, then the electrolyte film, the positive electrode sheet and the negative electrode sheet are dried, and then the negative electrode sheet, the electrolyte film and the positive electrode sheet are sequentially stacked and placed in sequence, and the solid-state battery as shown in Figure 1 is obtained by heat isostatic pressing.

[0066] Since the electrolyte membrane, the positive electrode sheet and the negative electrode sheet are obtained by coating, solvent volatilization treatment is required. However, the current process flow adopts the uniform heating mode, which can cause the edge thinning or edge thickening material to be cast and cracked due to the uneven thickness distribution of each part. Therefore, in order to avoid this situation, the drying oven is arranged in the processing system and the infrared local radiation heating mode is adopted for solvent volatilization treatment. The infrared radiation source (for example, infrared lamp) is installed in the drying oven, and the heat is concentrated to the area with relatively thick thickness through the directional reflection mirror.

[0067] In some preferred embodiments, as shown in FIG. 4, the first protruding part 4021 is the same as the second protruding part 4011. Figure 3

[0068] In the utility model, the main part of the prepared electrolyte membrane is in a symmetrical structure when the first protruding part is the same as the second protruding part.

[0069] In some preferred embodiments, as shown in FIG. 4, the height of the first protruding part 4021 gradually decreases from the middle to both sides, and the height of the second protruding part 4011 gradually decreases from the middle to both sides. Figure 3

[0070] In the utility model, by setting the first protruding part and the second protruding part as the structure of thick in the middle and thin on both sides, the main part of the prepared electrolyte membrane can be ensured to be in the structure of thick in the middle and thin on both sides, thereby increasing the contact area of the positive electrode sheet, the negative electrode sheet and the electrolyte membrane, inhibiting the poor contact problem in the charging and discharging process, and the larger interface contact area enhances the ion transmission efficiency of the battery, which can further improve the rate performance.

[0071] In some preferred embodiments, the first protruding part includes a middle region and an edge region, and the width of the middle region accounts for 90-99% of the total width of the first protruding part in the second direction; and the thickness of the middle region is greater than the thickness of the edge region in the first direction.

[0072] In some preferred embodiments, the second protruding part includes a middle region and an edge region, and the width of the middle region accounts for 90-99% of the total width of the second protruding part in the second direction; and the thickness of the middle region is greater than the thickness of the edge region in the first direction.

[0073] ​​It should be noted that, in the actual manufacturing process, the edge and middle region differential design is realized by synchronously adjusting the thickness of the electrolyte film and the positive electrode sheet and the negative electrode sheet, and monitoring and adjusting the edge thickness of the positive electrode sheet, the negative electrode sheet and the electrolyte film in the positive electrode processing device, the negative electrode processing device and the electrolyte film processing device, and the electrolyte film can be completely attached and coated with the edge of the positive electrode sheet and the negative electrode sheet.

[0074] In some preferred embodiments, a plurality of infrared lamps are arranged in the oven, and the infrared lamps are arranged above the first part 2011 of the main body part 201 of the electrolyte film 20 when the electrolyte film is placed in the oven.

[0075] In the utility model, the edge and the middle are heated differentially through the arrangement of multiple infrared lamps, the problem of overlapping overheating of the edge region and the middle region is avoided, and the material surface is uniformly heated by infrared radiation, which is suitable for the design of large edge thickness difference.

[0076] In one specific embodiment, a plurality of uniformly arranged infrared lamps are arranged above the oven, and the infrared lamps located at the edge region of the main body part of the electrolyte film are turned on when the electrolyte film is placed in the oven; the infrared lamps located at the fourth part of the positive electrode sheet or the sixth part of the negative electrode sheet are turned on when the positive electrode sheet or the negative electrode sheet is placed in the oven. In this way, the different structures of the materials to be dried are correspondingly turned on at different positions of the infrared lamps, so that the differential heating of different structures of the materials is realized, and the applicability of the oven is improved.

[0077] In some preferred embodiments, the isostatic press adopts a staged hot isostatic pressing process.

[0078] In the utility model, the problem of uneven local stress in a large-area battery is effectively solved by segmental pressure application and dynamic adjustment of pressure distribution, such as pre-pressing to preliminarily arrange the particles in the battery, to exclude excess gas and reduce the interface gap, to further compact the particles in the battery, to significantly reduce the gap between the electrolyte film and the positive electrode sheet and the negative electrode sheet, to improve the overall compactness and interface bonding performance, and to further improve the structural integrity of the battery. In addition, in combination with the self-adaptive pressure sensor, the pressure change can be monitored in real time in the finished solid-state battery test, so as to further ensure the stability of the solid-state battery in the working environment.

[0079] The utility model will be further described by way of example in the following, but the protection scope of the utility model is not limited to these embodiments.

[0080] In the following Example 1 and Comparative Examples 1-2, the preparation method of the electrolyte film is as follows: LPSCl powder and butyl rubber NBR with a mass ratio of 95:5 are weighed, dimethylbenzene is added as a solvent, and the raw materials are fully mixed and uniformly distributed to obtain a slurry for preparing an electrolyte film. An electrolyte film is prepared using a wet coating process by using an electrolyte film processing device as shown in Figure 3 After oven drying, an electrolyte film as shown in Figure 2 is obtained.

[0081] The preparation method of the positive electrode sheet is as follows: NCM811, LPSCl powder, VGCF and butyl rubber NBR are weighed with a mass ratio of 70:30:3:2, dimethylbenzene is added as a solvent, and the raw materials are fully mixed and uniformly distributed to form a slurry. Then, a positive electrode film is prepared by coating the slurry on an aluminum foil using a wet coating process. After oven drying, a positive electrode sheet as shown in Figure 1 is obtained.

[0082] The preparation method of the negative electrode sheet is as follows: SiO, LPSCl powder, VGCF and butyl rubber NBR are weighed with a mass ratio of 60:40:3:2, dimethylbenzene is added as a solvent, and the raw materials are fully mixed and uniformly distributed to form a slurry. Then, a negative electrode film is prepared by coating the slurry on a copper foil using a wet coating process. After oven drying, a negative electrode sheet as shown in Figure 1 is obtained.

[0083] Preparation of soft package solid-state battery: as shown in Figure 1 , the negative electrode sheet, electrolyte film and positive electrode sheet are sequentially stacked, and then placed in a hot isostatic pressing machine for hierarchical hot isostatic pressing to form a solid-state battery.

[0084] Battery performance test: the soft package batteries prepared in the examples and comparative examples are subjected to charge and discharge test, the voltage range of the test voltage is 2.5-4.3 V, the test rate is 0.3C, and the first cycle discharge specific capacity and the discharge specific capacity after 100 cycles of the battery are recorded. The capacity retention rate (%) of 100 cycles = 100 cycle discharge specific capacity / first cycle discharge specific capacity x 100%.

[0085] Example 1

[0086] As shown in Figure 1 and Figure 2 , a solid-state battery includes a positive electrode sheet 10, an electrolyte film 20 and a negative electrode sheet 30; the electrolyte film includes a main body part 201 and an extension part 202, the main body part 201 is formed with a first concave surface and a second concave surface, the first concave surface and the second concave surface are in a first direction (such as Figure 1The extension portion 202 includes a first extension portion 2021 and a second extension portion 2022 oppositely arranged and the first extension portion 2021 and the second extension portion 2022 are arranged on one side of the positive electrode sheet 10 or the negative electrode sheet 30 respectively in the second direction (Y direction shown in the figure). Figure 1 The first direction and the second direction are perpendicular to each other; the positive electrode sheet 10, the electrolyte film 20 and the negative electrode sheet 30 are arranged in axial symmetry.

[0087] The main body portion 201 of the electrolyte film 20 includes a first portion 2011 and a second portion 2012, in the first direction, the thickness of the first portion 2011 is greater than the thickness of the second portion 2012; in the second direction, the width of the second portion 2012 of the main body portion 201 of the electrolyte film 20 accounts for 90% of the total width of the main body portion 201; the main body portion 201 of the electrolyte film 20 includes a first portion 2011 and a second portion 2012, in the first direction, the difference between the thickness of the first portion 2011 and the thickness of the second portion 2012 is 5 μm; and along the first direction, the main body portion 201 of the electrolyte film gradually increases in thickness from the center of the second portion 2012 towards the first portion 2011.

[0088] In the second direction, the width of the first extension portion 2021 and the width of the second extension portion 2022 are both 30 μm; in the second direction, the width of the positive electrode sheet 10 is the same as the width of the negative electrode sheet 30; the width of the electrolyte film 20 is the same as the sum of the width of the positive electrode sheet 10, the width of the first extension portion and the width of the second extension portion; in the first direction, the thickness of the extension portion of the electrolyte film is the same as the sum of the thickness of the positive electrode sheet, the thickness of the main body portion of the electrolyte film and the thickness of the negative electrode sheet.

[0089] The first concave surface faces the positive electrode sheet 10 and is fitted with the positive electrode sheet 10, the positive electrode sheet 10 includes a third portion and a fourth portion, in the first direction, the thickness of the third portion is less than the thickness of the fourth portion, and the extension portion 202 of the electrolyte film 20 is fitted with the side wall of the third portion of the positive electrode sheet 10, that is, the positive electrode sheet 10 has a structure of thick in the middle and thin at the edges.

[0090] The second concave surface faces the negative electrode sheet 30 and is fitted with the negative electrode sheet 30, the negative electrode sheet 30 includes a fifth portion and a sixth portion, in the first direction, the thickness of the fifth portion is less than the thickness of the sixth portion, and the extension portion 202 of the electrolyte film 20 is fitted with the side wall of the fifth portion of the negative electrode sheet 30, that is, the negative electrode sheet 30 has a structure of thick in the middle and thin at the edges; the projection of the positive electrode sheet 10 and the negative electrode sheet 30 on the horizontal plane is a rectangle of 8 cm x 6 cm.

[0091] The battery performance test results are as follows: after 100 cycles, the battery still retains 80% of its specific capacity, i.e., 150mAh / g.

[0092] Comparative Example 1

[0093] like Figure 4 As shown, a solid-state battery includes: a positive electrode 10, an electrolyte membrane 20, and a negative electrode 30; in a second direction, the electrolyte membrane 20, the positive electrode 10, and the negative electrode 30 all have the same width; in a first direction, the electrolyte membrane 20 has a uniform thickness, which is the same as the thickness of the second part 2012 of the main body portion 201 of the electrolyte membrane 20 in Example 1; the positive electrode 10 and the negative electrode 30 have uniform thicknesses, and the total thickness of the solid-state battery is the same as the total thickness of the solid-state battery in Example 1.

[0094] The battery performance test results showed that the battery developed a short circuit after two cycles.

[0095] Comparative Example 2

[0096] like Figure 5 As shown, a solid-state battery includes: a positive electrode 10, an electrolyte membrane 20, and a negative electrode 30; in a second direction, the widths of the positive electrode 10 and the negative electrode 30 are the same, and the width of the electrolyte membrane 20 is 60 μm wider than the width of the positive electrode 10, and 30 μm wider on each side; in a first direction, the thickness of the electrolyte membrane is uniform, and is the same as the thickness of the second part of the main body of the electrolyte membrane in Example 1; the thicknesses of the positive electrode and the negative electrode are uniform, and the total thickness of the solid-state battery is the same as the total thickness of the solid-state battery in Example 1.

[0097] The battery performance test results are as follows: after 100 cycles, the battery can only retain 20% of its specific capacity, which is only 37.5 mAh / g.

[0098] It should be noted that, Figure 2 The dashed lines in the diagram are only used to distinguish the main body, the extension, and the first and second parts, and do not indicate that the structure or composition of the electrolyte membrane has strict divisions.

[0099] Example 2

[0100] This embodiment provides a solid-state battery processing system, including: an electrolyte membrane processing device, a positive electrode processing device, a negative electrode processing device, an oven, and an isostatic press; the electrolyte membrane processing device is used to prepare an electrolyte membrane for a solid-state battery; the positive electrode processing device is used to prepare a positive electrode sheet for a solid-state battery; the negative electrode processing device is used to prepare a negative electrode sheet for a solid-state battery; the oven is used to dry the electrolyte membrane, positive electrode sheet, and negative electrode sheet; the isostatic press is used to perform hot isostatic pressing treatment on the dried and stacked positive electrode sheet, electrolyte membrane, and negative electrode sheet to obtain a solid-state battery;

[0101] As shown in Figure 3 , the electrolyte membrane processing device comprises a coating tool head and a coating base 401; the coating tool head is provided with a scraper body 402, the central region of the scraper body 402 is provided with a first protruding part 4021, and the scraper body is symmetrically distributed; the central region of the coating base is provided with a second protruding part 4011; the first protruding part 4021 and the second protruding part 4011 both have a structure of thick in the middle and thin on both sides; the first protruding part 4021 is used to form a first concave surface of the main body part of the electrolyte membrane of the aforementioned solid-state battery, and the second protruding part 4011 is used to form a second concave surface of the main body part of the electrolyte membrane of the aforementioned solid-state battery. Since the above-mentioned electrolyte membrane is provided with two concave surfaces, the thickness of the middle region of the main body part of the electrolyte membrane is lower than the thickness of the edge region, so it is necessary to design a special scraper body and a coating base according to the structure of the above-mentioned electrolyte membrane, so as to obtain the above-mentioned electrolyte membrane by using the scraper body and the coating base in cooperation. The proportion of the edge region of the first protruding part and the second protruding part can be further limited according to the structure of the electrolyte membrane, so as to obtain the required electrolyte membrane, which is adapted to and covered by the prepared positive electrode sheet and negative electrode sheet.

[0102] First, an electrolyte membrane is prepared by using an electrolyte membrane processing device as shown in Figure 1 , then a positive electrode sheet and a negative electrode sheet are prepared by using a positive electrode processing device and a negative electrode processing device as shown in Figure 1 , then the electrolyte membrane, the positive electrode sheet and the negative electrode sheet are dried, and then the negative electrode sheet, the electrolyte membrane and the positive electrode sheet are sequentially stacked and placed, and a hot isostatic pressing treatment is performed to obtain a solid-state battery as shown in Figure 1 . The processing system is provided with an oven, and the solvent volatilization treatment is performed in the way of infrared local radiation heating. An infrared radiation source (for example, an infrared lamp) is installed in the oven, and the heat is concentrated to the region with relatively large thickness by directional reflection mirror. Specifically, when the electrolyte membrane is placed in the oven, the infrared lamp is arranged directly above the first part of the main body part of the electrolyte membrane.

[0103] It should be noted that in this document, relational terms such as first and second are used solely to distinguish one entity from another entity, without necessarily requiring or implying any actual such relationship or order between these entities.

[0104] Finally, it should be noted that: the above examples are used to illustrate the technical solutions of the present application, but not limited to; although the present application is described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still be modified to the technical solutions recorded in the foregoing examples, or part of the technical features are replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A solid-state battery, characterized by, include: A positive electrode, an electrolyte membrane, and a negative electrode; the electrolyte membrane includes a main body portion and an extension portion, the main body portion having a first concave surface and a second concave surface, the first concave surface and the second concave surface respectively adhering to one side of the positive electrode or the negative electrode in a first direction, the extension portion including a first extension portion and a second extension portion disposed opposite to each other, the first extension portion and the second extension portion respectively adhering to and covering one side of the positive electrode and the negative electrode in a second direction, the first direction and the second direction being perpendicular to each other.

2. The solid-state battery of claim 1, wherein: The electrolyte membrane, the positive electrode, and the negative electrode are all arranged in an axially symmetrical manner.

3. The solid-state battery of claim 1, wherein: The main body of the electrolyte membrane includes a first part and a second part. In a first direction, the thickness of the first part is greater than the thickness of the second part. In a second direction, the width of the second part of the main body of the electrolyte membrane accounts for 90 to 99% of the total width of the entire main body.

4. The solid-state battery of claim 1, wherein: The main body of the electrolyte membrane includes a first part and a second part. In a first direction, the thickness difference between the first part and the second part is 3~10μm, and along the first direction, the main body of the electrolyte membrane shows a gradual increase in thickness from the center of the second part toward the first part.

5. The solid-state battery of claim 1, wherein: The positive electrode sheet includes a third part and a fourth part. In the first direction, the thickness of the third part is less than the thickness of the fourth part, and the extension portion of the electrolyte membrane is attached to the sidewall of the third part of the positive electrode sheet. And / or, The negative electrode sheet includes a fifth part and a sixth part. In the first direction, the thickness of the fifth part is less than the thickness of the sixth part, and the extension portion of the electrolyte membrane is attached to the sidewall of the fifth part of the negative electrode sheet.

6. The solid-state battery of claim 1, wherein: In the second direction, the width of the first extension and the second extension of the electrolyte membrane are both 10~50μm; in the first direction, the thickness of the extension of the electrolyte membrane is the same as the sum of the thickness of the positive electrode, the thickness of the main body of the electrolyte membrane, and the thickness of the negative electrode.

7. The solid-state battery of claim 1, wherein: The thickness of the positive electrode is the same as the thickness of the negative electrode. In the first direction, the thickness of the extended portion of the electrolyte membrane is the same as the sum of the thickness of the positive electrode, the thickness of the main body portion of the electrolyte membrane, and the thickness of the negative electrode. In the second direction, the width of the positive electrode is the same as the width of the negative electrode; the width of the electrolyte membrane is the same as the sum of the width of the positive electrode, the width of the first extension, and the width of the second extension. or, The thickness of the positive electrode is different from the thickness of the negative electrode. In the first direction, the thickness of the extended portion of the electrolyte membrane is the same as the sum of the thickness of the positive electrode, the thickness of the main body portion of the electrolyte membrane, and the thickness of the negative electrode. In the second direction, the width of the positive electrode is the same as the width of the negative electrode; the width of the electrolyte membrane is the same as the sum of the width of the positive electrode, the width of the first extension, and the width of the second extension.

8. A processing system for producing a solid-state battery as claimed in any one of claims 1 to 7, characterized by include: Electrolyte membrane processing equipment, positive electrode processing equipment, negative electrode processing equipment, drying oven, isostatic press; The electrolyte membrane processing device is used for preparing the electrolyte membrane of the solid-state battery; The positive electrode processing device is used for preparing the positive electrode sheet of the solid-state battery; The negative electrode processing device is used for preparing the negative electrode sheet of the solid-state battery; The oven is used for drying the electrolyte membrane, the positive electrode sheet and the negative electrode sheet; The isostatic press is used for hot isostatic pressing the positive electrode sheet, the electrolyte membrane and the negative electrode sheet which are stacked after drying to obtain the solid-state battery; The electrolyte membrane processing device comprises a coating tool head and a coating base; the coating tool head is provided with a scraper body, the center area of the scraper body is provided with a first protruding part, and the scraper body is symmetrically distributed; the center area of the coating base is provided with a second protruding part; the first protruding part and the second protruding part are both in a structure of thick in the middle and thin on both sides, the first protruding part is used for forming a first concave surface of a main body part of the electrolyte membrane, and the second protruding part is used for forming a second concave surface of the main body part of the electrolyte membrane.

9. The processing system of claim 8, wherein: The first protruding part is the same as the second protruding part; and / or, The height of the first protruding part gradually decreases from the middle to both sides, and the height of the second protruding part gradually decreases from the middle to both sides.

10. The processing system of claim 8, wherein: The oven is provided with a plurality of infrared lamps, and when the electrolyte membrane is placed in the oven, the infrared lamps are correspondingly arranged above the first part of the main body part of the electrolyte membrane.

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