Preparation method of special-shaped solid-state unit cell, unit cell and battery

Abstract

The invention provides a preparation method of a special-shaped solid unit cell, a unit cell and a battery, and the preparation method comprises the following steps: S1, fixedly arranging electrolyte membranes on two sides of a negative pole piece to obtain an electrolyte membrane / negative pole composite structure, and putting the composite structure into a first special-shaped clamp; s2, carrying out first isostatic pressing treatment on a first special-shaped clamp bearing the composite structure of the electrolyte membrane / negative electrode; s3, after the first isostatic pressing treatment, obtaining an electrolyte membrane / negative electrode composite pole piece which is profiled with the clamping bin of the first special-shaped clamp; s4, fixing the positive pole piece on the two sides of the electrolyte membrane / negative pole composite pole piece, and putting the positive pole piece and the negative pole composite pole piece into a second special-shaped clamp; s5, carrying out second isostatic pressing treatment on the second special-shaped clamp bearing the positive electrode / electrolyte membrane / negative electrode composite structure; s6, after second isostatic pressing treatment, obtaining a unit battery cell which is profiled with the clamping bin of the second special-shaped clamp; and the preparation process of the unit cell is simple, the compatibility of the unit cell is high, and mass production is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a method for preparing a special-shaped solid-state unit battery cell, a special-shaped solid-state unit battery cell and a special-shaped all-solid-state battery. Background Art

[0002] With the continuous development of science and technology, human beings' demand for energy is increasing day by day. Nowadays, lithium batteries have been widely used in automobiles, mobile phones, tablet computers and other devices. Especially with the improvement of people's material living standards, the demand for lithium batteries is also increasing. Among them, new demands have been put forward for lithium batteries that can be used in special scenarios such as VR glasses and Bluetooth headsets.

[0003] Since traditional square shell, soft pack and cylindrical batteries are all rectangular or cylindrical, they cannot meet the application in the above scenarios. At the same time, compared with traditional liquid lithium batteries, all-solid-state batteries have higher energy density and safety. Therefore, in order to meet people's expectations for high energy density and high safety batteries, it is urgent to develop a special-shaped all-solid-state battery with a special appearance.

[0004] However, isostatic pressing technology is often used in the preparation of all-solid-state batteries to improve battery performance and quality, but it also results in high density and poor toughness of the battery electrodes, making them difficult to bend. There is currently no solution for preparing special-shaped all-solid-state batteries. Summary of the invention

[0005] The purpose of the present invention is to provide an improved method for preparing special-shaped solid-state unit cells, special-shaped solid-state unit cells and special-shaped solid-state batteries to address the problem that the application of isostatic pressing technology in battery preparation makes it impossible to obtain special-shaped all-solid-state batteries with special appearance and morphology, and to solve one of the above-mentioned technical problems.

[0006] The specific technical solutions of the present invention are as follows:

[0007] First, the present invention provides a method for preparing a special-shaped solid-state unit battery cell, comprising the following steps:

[0008] S1: fixing the electrolyte membrane on both sides of the negative electrode plate to obtain an electrolyte membrane / negative electrode composite structure, and placing the electrolyte membrane / negative electrode composite structure into a first special-shaped fixture;

[0009] S2: performing a first isostatic pressing process on the first special-shaped fixture carrying the composite structure of the electrolyte membrane / negative electrode;

[0010] S3: After the first isostatic pressing treatment, an electrolyte membrane / negative electrode composite electrode sheet conforming to the clamping chamber of the first special-shaped clamp is obtained;

[0011] S4: fixing the positive electrode sheet on both sides of the electrolyte membrane / negative electrode composite sheet to obtain a positive electrode / electrolyte membrane / negative electrode composite structure, and placing the positive electrode / electrolyte membrane / negative electrode composite structure into a second special-shaped fixture;

[0012] S5: performing a second isostatic pressing process on the second special-shaped fixture carrying the composite structure of the positive electrode / electrolyte membrane / negative electrode;

[0013] S6: After the second isostatic pressing treatment, a unit cell having a shape similar to the clamping bin of the second anisotropic clamp is obtained.

[0014] In a possible implementation manner, the solid electrolyte in the electrolyte membrane is a sulfide solid electrolyte, a halide solid electrolyte, or a composite electrolyte of sulfide and halide.

[0015] In a possible implementation manner, the first isostatic pressing treatment satisfies at least one of the following characteristics:

[0016] Isostatic pressure is 50~500MPa;

[0017] Isostatic pressing temperature is 20-120°C;

[0018] The isostatic pressing time is 1 to 500 minutes.

[0019] In a possible implementation manner, the second isostatic pressing treatment satisfies at least one of the following characteristics:

[0020] Isostatic pressure is 100~600MPa;

[0021] Isostatic pressing temperature is 20-120°C;

[0022] The isostatic pressing time is 1 to 500 minutes.

[0023] In a possible implementation manner, the clamping bin of the first special-shaped clamp and the clamping bin of the second special-shaped clamp have the same shape.

[0024] In a possible implementation manner, the first special-shaped fixture and the second special-shaped fixture satisfy at least one of the following:

[0025] The clamping compartment of the first special-shaped clamp is provided with a first permeable layer, and the first permeable layer is used to fit with two side surfaces of the composite structure of the electrolyte membrane / negative electrode;

[0026] A second permeable layer is disposed inside the second special-shaped fixture, and the second permeable layer is bonded to two side surfaces of the composite structure of the positive electrode / electrolyte membrane / negative electrode.

[0027] In a possible implementation manner, the first permeable layer and the second permeable layer satisfy at least one of the following:

[0028] The first permeable layer comprises at least one of non-woven fabric, foam and sponge;

[0029] The second permeable layer includes at least one of non-woven fabric, foam and sponge.

[0030] In a possible implementation manner, the preparation method satisfies at least one of the following:

[0031] The thickness of the first permeable layer is 0.1 to 1 mm;

[0032] The thickness of the second permeable layer is 0.1 to 1 mm;

[0033] The curvature of the positive electrode sheet is 0 to 20 degrees;

[0034] The bending curvature of the negative electrode plate is 0-20.

[0035] Second, the present invention provides a special-shaped solid-state unit battery cell, which is prepared by the above-mentioned preparation method.

[0036] Third, the present invention provides a special-shaped all-solid-state battery, which is obtained by stacking multiple special-shaped solid-state unit cell layers, connecting the pole ears in parallel, and finally welding the pole ears and packaging to obtain the special-shaped solid-state battery, wherein the special-shaped solid-state unit cell layer is the special-shaped solid-state unit cell as described above.

[0037] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0038] The present invention can obtain an electrolyte membrane / negative electrode composite plate that is shaped like the clamping bin of the first special-shaped clamp by performing a first isostatic pressing treatment on the electrolyte membrane / negative electrode composite structure in the first special-shaped clamp; and obtain a unit battery cell that is shaped like the clamping bin of the first special-shaped clamp by using a second special-shaped clamp to perform a second isostatic pressing on the positive electrode plate and the electrolyte membrane / negative electrode composite plate. Since the first special-shaped clamp and the second special-shaped clamp have simple structures, the preparation process of the special-shaped unit battery cell is simple and efficient. At the same time, by correspondingly arranging the first permeable layer and the second permeable layer inside the first special-shaped clamp and the second special-shaped clamp, the isostatic liquid can be allowed to penetrate while maintaining the shape of the unit battery cell and the electrolyte membrane / negative electrode composite plate, thereby improving the isostatic pressing effect. The material cost of the first permeable layer and the second permeable layer is low, which can reduce the preparation cost of the battery cell; and the unit battery cell and the electrolyte membrane / negative electrode composite plate obtained after isostatic pressing are highly compatible with the lamination process and equipment in the industry, and are convenient for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 A flow chart showing a method for preparing a special-shaped solid-state unit battery cell provided by the present invention is shown;

[0041] Figure 2 A schematic diagram of the cross-sectional structure of an electrolyte membrane / negative electrode composite electrode sheet provided according to the present invention is shown;

[0042] Figure 3 A schematic diagram of the cross-sectional structure of a unit cell provided according to the present invention is shown;

[0043] Figure 4 A schematic cross-sectional structure diagram of a first special-shaped fixture provided according to the present invention on which an electrolyte membrane / negative electrode composite electrode sheet is placed is shown;

[0044] Figure 5 A schematic cross-sectional structure diagram of a second special-shaped fixture on which a unit battery cell is placed according to the present invention is shown;

[0045] Figure 6 A schematic cross-sectional structure diagram of an S-shaped clamp provided according to the present invention is shown;

[0046] The reference numerals in the accompanying drawings are as follows:

[0047] 1-electrolyte membrane, 2-negative electrode sheet, 3-positive electrode sheet, 4-first special-shaped fixture, 5-first permeation layer, 6-second special-shaped fixture, 7-second permeation layer, 10-electrolyte membrane / negative electrode composite sheet, 20-unit battery cell, 30-S-type fixture. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0049] For the following defined terms, these definitions shall apply unless a different definition is given elsewhere in the claims or specification. All numerical values, whether or not explicitly indicated, are defined herein as modified by the term "about". The term "about" generally refers to a numerical range that is considered by those skilled in the art to be equivalent to the stated values ​​to produce substantially the same properties, functions, results, etc. A numerical range indicated by a lower value and a higher value is defined to cover all numerical values ​​included in this numerical range and all subranges included in this numerical range.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including", "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] The following describes the embodiments of the present invention in conjunction with the accompanying drawings. Figure 1-6 The drawings do not have any limiting effect on the disclosed content recorded in the claims.

[0052] First, an embodiment of the present invention provides a method for preparing a special-shaped solid-state unit battery cell 20, comprising the following steps:

[0053] S1: The electrolyte membrane 1 is fixedly arranged on both sides of the negative electrode plate 2 to obtain an electrolyte membrane / negative electrode composite structure, and the electrolyte membrane / negative electrode composite structure is placed in a first special-shaped fixture 4;

[0054] Specifically, the electrolyte membrane 1 can be fixedly connected to both sides of the negative electrode plate 2 by means of adhesive pressing.

[0055] Specifically, before the electrolyte membrane / negative electrode composite structure is placed in the first special-shaped fixture 4 in S1, it needs to be sealed. The sealing process can use a sealing bag to seal the electrolyte membrane / negative electrode composite structure, thereby effectively protecting the internal environment of the electrolyte membrane / negative electrode composite structure, preventing the intrusion of moisture, oxygen and other impurities, and maintaining the electrochemical stability of the electrolyte membrane 1 and the negative electrode plate 2. This is crucial for the long-term stable operation of the battery.

[0056] Specifically, the sealing bag may be a polypropylene (PP) film, a polyethylene (PE) film, a polyvinyl chloride (PVC) film, or a polyethylene terephthalate (PET) film.

[0057] S2: subjecting the first special-shaped fixture 4 carrying the composite structure of the electrolyte membrane / negative electrode to a first isostatic pressing treatment;

[0058] It should be noted that isostatic pressing is a treatment method that applies isotropic pressure to an object through a liquid medium, which can improve the density and uniformity of composite materials and metal materials, thereby improving the strength and durability of the materials. In the preparation process of batteries, isostatic pressing technology introduces high-pressure liquid into the positive and negative electrode materials of the battery, so that the electrolyte solution inside the battery is more evenly distributed between the electrodes, thereby improving the energy density and cycle life of the battery. In addition, isostatic pressing technology can also reduce defects and stress concentration inside the battery, improving the safety performance of the battery.

[0059] Specifically, the first special-shaped clamp 4 has a clamping chamber, and the electrolyte membrane / negative electrode composite structure after sealing is accommodated in the clamping chamber, and the two side surfaces of the electrolyte membrane / negative electrode composite structure are in contact with the clamping chamber.

[0060] Specifically, the processing parameters of the first isostatic pressing process at least meet one of the following characteristics: the isostatic pressing pressure is 50-500 MPa; the isostatic pressing temperature is 20-120° C.; and the isostatic pressing time is 1-500 min.

[0061] Exemplarily, the first special-shaped fixture 4 carrying the composite structure of the electrolyte membrane / negative electrode is placed in an isostatic pressing device, and the parameters of the isostatic pressing device are adjusted so that the isostatic pressing pressure can be 300 MPa, the isostatic pressing temperature is 60° C., and the isostatic pressing time is 10 min.

[0062] Specifically, the shape of the clamping bin of the first special-shaped clamp 4 can be C-shaped or S-shaped, etc., and can be designed according to actual specific usage requirements, which is not limited in this embodiment.

[0063] like Figure 6 Shown in FIG. 3 is an S-shaped clamp 30 having an S-shaped clamping chamber.

[0064] Specifically, after the first isostatic pressing treatment, the composite structure of the electrolyte membrane / negative electrode built into the first special-shaped fixture 4 can be bent according to the designed shape of the clamping compartment of the first special-shaped fixture 4 .

[0065] S3: After the first isostatic pressing treatment, an electrolyte membrane / negative electrode composite electrode sheet 10 conforming to the clamping chamber of the first special-shaped clamp 4 is obtained;

[0066] Specifically, the electrolyte membrane / negative electrode composite electrode sheet 10 after the first isostatic pressing treatment has the same shape as the clamping chamber of the first special-shaped clamp 4 .

[0067] S4: Fix the positive electrode sheet 3 on both sides of the electrolyte membrane / negative electrode composite sheet 10 to obtain a positive electrode / electrolyte membrane / negative electrode composite structure, and place the positive electrode / electrolyte membrane / negative electrode composite structure into a second special-shaped fixture 6;

[0068] Specifically, before step S4, since the outer surface of the electrolyte membrane / negative electrode composite electrode sheet 10 after the first isostatic pressing treatment is tightly attached to the sealing bag, the sealing bag needs to be disassembled.

[0069] Specifically, the positive electrode plate 3 can be fixed on both sides of the electrolyte membrane / negative electrode composite plate 10 by gluing and pressing.

[0070] Specifically, the pressed composite structure of the positive electrode / electrolyte membrane / negative electrode is sealed by a sealing bag to ensure the stability of its internal chemical properties.

[0071] Specifically, the sealed positive electrode / electrolyte membrane / negative electrode composite structure is placed in the clamping chamber of the second special-shaped clamp 6, and the two side surfaces of the positive electrode / electrolyte membrane / negative electrode composite structure are in contact with the inner wall of the clamping chamber.

[0072] S5: performing a second isostatic pressing treatment on the second special-shaped fixture 6 carrying the composite structure of the positive electrode / electrolyte membrane / negative electrode;

[0073] Specifically, the processing parameters of the second isostatic pressing process at least meet one of the following characteristics: the isostatic pressing pressure is 100-600 MPa; the isostatic pressing temperature is 20-120° C.; and the isostatic pressing time is 1-500 min.

[0074] Exemplarily, the second special-shaped fixture 6 carrying the composite structure of the electrolyte membrane / negative electrode is placed in an isostatic pressing device, and the parameters of the isostatic pressing device are adjusted so that the isostatic pressing pressure can be 400 MPa, the isostatic pressing temperature is 60° C., and the isostatic pressing time is 10 min.

[0075] Specifically, the shape of the clamping bin of the second special-shaped clamp 6 can be C-shaped or S-shaped, etc., and can be designed according to actual specific usage requirements, which is not limited in this embodiment.

[0076] Specifically, after the second isostatic pressing treatment, the composite structure of the positive electrode / electrolyte membrane / negative electrode built into the second special-shaped fixture 6 can be bent according to the designed shape of the clamping compartment of the second special-shaped fixture 6 .

[0077] S6: After the second isostatic pressing treatment, a unit cell 20 conforming to the clamping bin of the second anisotropic clamp is obtained.

[0078] Specifically, the shape of the positive electrode / electrolyte membrane / negative electrode composite electrode sheet 10 after the second isostatic pressing treatment is the same as the shape of the clamping chamber of the second special-shaped clamp 6 .

[0079] Specifically, since the outer surface of the positive electrode / electrolyte membrane / negative electrode composite electrode sheet 10 after the second isostatic pressing treatment is tightly attached to the sealing bag, the sealing bag needs to be disassembled.

[0080] In some embodiments, the solid electrolyte in the electrolyte membrane 1 in step S1 is a sulfide solid electrolyte, a halide solid electrolyte, or a composite electrolyte of sulfide and halide.

[0081] Preferably, the solid electrolyte in the electrolyte membrane 1 is a sulfide and halide composite electrolyte.

[0082] In some embodiments, the clamping bin of the first special-shaped clamp 4 and the clamping bin of the second special-shaped clamp 6 have the same shape.

[0083] Specifically, the material clamped in the clamping compartment of the second special-shaped clamp 6 is a composite structure of positive electrode / electrolyte membrane / negative electrode, and the material clamped in the clamping compartment of the first special-shaped clamp 4 is a composite structure of electrolyte membrane / negative electrode; the composite structure of positive electrode / electrolyte membrane / negative electrode is thicker than the composite structure of electrolyte membrane / negative electrode, so the longitudinal width of the clamping compartment of the second special-shaped clamp 6 is greater than the longitudinal width of the clamping compartment of the first special-shaped clamp 4.

[0084] In some embodiments, in the method for preparing the special-shaped solid-state unit battery cell 20, the first special-shaped clamp 4 and the second special-shaped clamp 6 satisfy at least one of the following: the clamping bin of the first special-shaped clamp 4 is provided with a first permeable layer 5, and the first permeable layer 5 is used to fit with the two side surfaces of the composite structure of the electrolyte membrane / negative electrode; the interior of the second special-shaped clamp 6 is provided with a second permeable layer 7, and the second permeable layer 7 is fitted with the two side surfaces of the composite structure of the positive electrode / electrolyte membrane / negative electrode.

[0085] Specifically, in step S1 , the first permeable layer 5 is arranged to fit the inner wall of the clamping chamber of the first special-shaped clamp 4 , so as to fit the two side surfaces of the composite structure of the electrolyte membrane / negative electrode.

[0086] Specifically, the second permeable layer 7 in step S4 is arranged to fit the inner wall of the clamping chamber of the second special-shaped clamp 6, so as to fit the two side surfaces of the composite structure of the positive electrode / electrolyte membrane / negative electrode.

[0087] In the present application, by setting a first permeable layer 5 on the inner wall of the clamping chamber of the first special-shaped clamp 4 and a second permeable layer 7 on the inner wall of the clamping chamber of the second special-shaped clamp 6, it is possible to allow isostatic liquid to penetrate while maintaining the shapes of the electrolyte membrane / negative electrode composite electrode sheet 10 and the positive electrode / electrolyte membrane / negative electrode composite electrode sheet, thereby improving the effects of the first isostatic pressing treatment and the second isostatic pressing treatment, respectively.

[0088] In some embodiments, the first permeable layer 5 and the second permeable layer 7 satisfy at least one of the following conditions: the first permeable layer 5 includes at least one of non-woven fabric, foam and sponge; the second permeable layer 7 includes at least one of non-woven fabric, foam and sponge.

[0089] Exemplarily, the first permeable layer 5 and the second permeable layer 7 may both be non-woven fabrics, and the cost of the permeable layer materials is low, which can reduce the preparation cost of the battery cell.

[0090] In some embodiments, the preparation method satisfies at least one of the following: the permeation layer thickness of the first permeation layer 5 is 0.1 to 1 mm; the permeation layer thickness of the second permeation layer 7 is 0.1 to 1 mm; the bending curvature of the positive electrode plate 3 is 0 to 20; and the bending curvature of the negative electrode plate 2 is 0 to 20.

[0091] Second, an embodiment of the present invention provides a special-shaped solid-state unit battery cell 20, and the special-shaped solid-state unit battery cell 20 is obtained by the above-mentioned preparation method.

[0092] Specifically, a special-shaped solid-state unit battery cell 20 conforming to the shape of the clamping bin of the first special-shaped clamp 4 is produced.

[0093] Third, an embodiment of the present invention provides a special-shaped all-solid-state battery, which is obtained by stacking multiple special-shaped solid-state unit cells 20 layers, connecting the pole ears in parallel, and finally welding the pole ears and packaging to obtain the special-shaped solid-state battery, wherein the special-shaped solid-state unit cell layer is the special-shaped solid-state unit cell 20 as described above.

[0094] Specifically, the number of stacking layers of the special-shaped solid-state unit cells 20 in the special-shaped solid-state battery is 1 to 20 pcs. During the stacking process, it is necessary to ensure that each cell is in close contact with each other without obvious gaps, thereby improving the energy density and performance of the battery.

[0095] Specifically, the positive and negative electrode tabs are aligned respectively, and then conventional tab welding and aluminum-plastic film packaging are performed to form the final multi-layer finished battery.

[0096] Specifically, the shape of the finally manufactured special-shaped solid-state battery is similar to the special-shaped solid-state unit battery cell 20 .

[0097] Specifically, the prepared special-shaped solid-state battery is subjected to charge and discharge tests to test its electrochemical performance, and the charge and discharge range of the charge and discharge test of the special-shaped solid-state battery is 2.8 to 4.2V.

[0098] Embodiment 1

[0099] This embodiment provides a preparation process of a special-shaped solid-state battery. Figure 1-6 , specifically including the following steps:

[0100] First, the sulfide electrolyte membrane and the negative electrode plate 2 are stacked and pressed to form an electrolyte membrane / negative electrode composite structure, and then sealed with a sealing bag and placed in a clamping bin of a first special-shaped clamp 4, and a 0.5 mm thick non-woven fabric penetration layer is provided on each of the two side walls of the clamping bin of the first special-shaped clamp 4 in contact with the electrolyte membrane / negative electrode composite structure; the first special-shaped clamp 4 with the built-in electrolyte membrane / negative electrode composite structure is placed in an isostatic pressing device for a first isostatic pressing treatment, the isostatic pressing pressure is 300 MPa, the isostatic pressing temperature is 60° C., and the isostatic pressing time is 10 min;

[0101] Further, the sealing bag on the isostatically pressed electrolyte membrane / negative electrode composite structure is disassembled to obtain an electrolyte membrane / negative electrode composite electrode sheet 10 conforming to the clamping bin of the first special-shaped clamp 4, the curvature of the negative electrode electrode sheet 2 is 10, and the length of the negative electrode electrode sheet 2 is 20 cm and the width is 10 cm;

[0102] Further, the positive electrode sheet 3 and the electrolyte membrane / negative electrode composite sheet 10 are stacked and pressed to form a composite structure of positive electrode / electrolyte membrane / negative electrode, and the composite structure is sealed with a sealing bag and placed in the clamping compartment of the second special-shaped fixture 6; a 0.5 mm thick non-woven fabric penetration layer is provided on each of the two side walls of the clamping compartment of the second special-shaped fixture 6 that are in contact with the composite structure of the positive electrode / electrolyte membrane / negative electrode; the second special-shaped fixture 6 with the composite structure of the positive electrode / electrolyte membrane / negative electrode built in isostatic pressing equipment is placed for a second isostatic pressing treatment, the isostatic pressing pressure is 400 MPa, the isostatic pressing temperature is 60° C., and the isostatic pressing time is 10 min;

[0103] Further, the sealing bag on the composite structure of the positive electrode / electrolyte membrane / negative electrode after isostatic pressing is disassembled to obtain a unit battery cell 20 that is shaped like the clamping bin of the second special-shaped fixture 6, and 5 pcs of unit battery cells 20 are stacked, the tabs are welded, and the aluminum-plastic film is encapsulated to obtain a special-shaped all-solid-state battery;

[0104] Finally, the prepared special-shaped all-solid-state battery was subjected to a pressurized charge and discharge test, with a charge cut-off voltage of 4.2V and a discharge cut-off voltage of 2.8V, to test the battery coulombic efficiency and cycle performance.

[0105] Embodiment 2

[0106] This embodiment provides a preparation process of a special-shaped solid-state battery. Figure 1-6 , specifically including the following steps:

[0107] First, the sulfide electrolyte membrane and the negative electrode plate 2 are stacked and pressed to form an electrolyte membrane / negative electrode composite structure, and then sealed with a sealing bag and placed in a clamping bin of a first special-shaped clamp 4, and a 0.1 mm thick non-woven fabric penetration layer is provided on each of the two side walls of the clamping bin of the first special-shaped clamp 4 in contact with the electrolyte membrane / negative electrode composite structure; the first special-shaped clamp 4 with the built-in electrolyte membrane / negative electrode composite structure is placed in an isostatic pressing device for a first isostatic pressing treatment, with an isostatic pressing pressure of 50 MPa, an isostatic pressing temperature of 20° C., and an isostatic pressing time of 1 min;

[0108] Further, the sealing bag on the isostatically pressed electrolyte membrane / negative electrode composite structure is disassembled to obtain an electrolyte membrane / negative electrode composite electrode sheet 10 conforming to the clamping bin of the first special-shaped clamp 4, the curvature of the negative electrode electrode sheet 2 is 1, and the length of the negative electrode electrode sheet 2 is 20 cm and the width is 10 cm;

[0109] Further, the positive electrode sheet 3 and the electrolyte membrane / negative electrode composite sheet 10 are stacked and pressed to form a composite structure of positive electrode / electrolyte membrane / negative electrode, and the composite structure is sealed with a sealing bag and placed in the clamping compartment of the second special-shaped fixture 6; a 0.1 mm thick non-woven fabric penetration layer is provided on each of the two side walls of the clamping compartment of the second special-shaped fixture 6 that are in contact with the composite structure of the positive electrode / electrolyte membrane / negative electrode; the second special-shaped fixture 6 with the composite structure of the positive electrode / electrolyte membrane / negative electrode built in isostatic pressing equipment is placed for a second isostatic pressing treatment, the isostatic pressing pressure is 100 MPa, the isostatic pressing temperature is 20° C., and the isostatic pressing time is 1 min;

[0110] Further, the sealing bag on the composite structure of the positive electrode / electrolyte membrane / negative electrode after isostatic pressing is disassembled to obtain a unit battery cell 20 that is shaped like the clamping bin of the second special-shaped fixture 6, and 5 pcs of unit battery cells 20 are stacked, the tabs are welded, and the aluminum-plastic film is encapsulated to obtain a special-shaped all-solid-state battery;

[0111] Finally, the prepared special-shaped all-solid-state battery was subjected to a pressurized charge and discharge test, with a charge cut-off voltage of 4.2V and a discharge cut-off voltage of 2.8V, to test the battery coulombic efficiency and cycle performance.

[0112] Embodiment 3

[0113] This embodiment provides a preparation process of a special-shaped solid-state battery. Figure 1-6 , specifically including the following steps:

[0114] First, the sulfide electrolyte membrane and the negative electrode plate 2 are stacked and pressed to form an electrolyte membrane / negative electrode composite structure, and then sealed with a sealing bag and placed in a clamping bin of a first special-shaped clamp 4, and a 1.0 mm thick non-woven fabric penetration layer is provided on each of the two side walls of the clamping bin of the first special-shaped clamp 4 in contact with the electrolyte membrane / negative electrode composite structure; the first special-shaped clamp 4 with the built-in electrolyte membrane / negative electrode composite structure is placed in an isostatic pressing device for a first isostatic pressing treatment, the isostatic pressing pressure is 500 MPa, the isostatic pressing temperature is 120° C., and the isostatic pressing time is 500 min;

[0115] Further, the sealing bag on the isostatically pressed electrolyte membrane / negative electrode composite structure is disassembled to obtain an electrolyte membrane / negative electrode composite electrode sheet 10 conforming to the clamping bin of the first special-shaped clamp 4, the curvature of the negative electrode electrode sheet 2 is 20, and the length of the negative electrode electrode sheet 2 is 20 cm and the width is 10 cm;

[0116] Further, the positive electrode sheet 3 and the electrolyte membrane / negative electrode composite sheet 10 are stacked and pressed to form a composite structure of positive electrode / electrolyte membrane / negative electrode, and the composite structure is sealed with a sealing bag and placed in the clamping compartment of the second special-shaped fixture 6; a 1.0 mm thick non-woven fabric penetration layer is provided on each of the two side walls of the clamping compartment of the second special-shaped fixture 6 that are in contact with the composite structure of the positive electrode / electrolyte membrane / negative electrode; the second special-shaped fixture 6 with the composite structure of the positive electrode / electrolyte membrane / negative electrode built in isostatic pressing equipment is placed for a second isostatic pressing treatment, the isostatic pressing pressure is 600 MPa, the isostatic pressing temperature is 120° C., and the isostatic pressing time is 500 min;

[0117] Further, the sealing bag on the composite structure of the positive electrode / electrolyte membrane / negative electrode after isostatic pressing is disassembled to obtain a unit battery cell 20 that is shaped like the clamping bin of the second special-shaped fixture 6, and 5 pcs of unit battery cells 20 are stacked, the tabs are welded, and the aluminum-plastic film is encapsulated to obtain a special-shaped all-solid-state battery;

[0118] Finally, the prepared special-shaped all-solid-state battery was subjected to a pressurized charge and discharge test, with a charge cut-off voltage of 4.2V and a discharge cut-off voltage of 2.8V, to test the battery coulombic efficiency and cycle performance.

[0119] Embodiment 4:

[0120] This embodiment provides a preparation process of a special-shaped solid-state battery. Figure 1-6 , specifically including the following steps:

[0121] First, the sulfide electrolyte membrane and the negative electrode plate 2 are stacked and pressed to form an electrolyte membrane / negative electrode composite structure, and then sealed with a sealing bag and placed in a clamping bin of a first special-shaped clamp 4, and a 0.5 mm thick sponge penetration layer is provided on each of the two side walls of the clamping bin of the first special-shaped clamp 4 in contact with the electrolyte membrane / negative electrode composite structure; the first special-shaped clamp 4 with the built-in electrolyte membrane / negative electrode composite structure is placed in an isostatic pressing device for a first isostatic pressing treatment, the isostatic pressing pressure is 300 MPa, the isostatic pressing temperature is 60° C., and the isostatic pressing time is 10 min;

[0122] Further, the sealing bag on the isostatically pressed electrolyte membrane / negative electrode composite structure is disassembled to obtain an electrolyte membrane / negative electrode composite electrode sheet 10 conforming to the clamping bin of the first special-shaped clamp 4, the bending rate of the negative electrode electrode sheet 2 is 10, and the length of the negative electrode electrode sheet 2 is 20 cm and the width is 10 cm;

[0123] Further, the positive electrode sheet 3 and the electrolyte membrane / negative electrode composite sheet 10 are stacked and pressed to form a composite structure of positive electrode / electrolyte membrane / negative electrode, and the composite structure is sealed with a sealing bag and placed in the clamping compartment of the second special-shaped fixture 6; a 0.5 mm thick sponge penetration layer is provided on each of the two side walls of the clamping compartment of the second special-shaped fixture 6 that are in contact with the composite structure of the positive electrode / electrolyte membrane / negative electrode; the second special-shaped fixture 6 with the composite structure of the positive electrode / electrolyte membrane / negative electrode built in isostatic pressing equipment is placed for a second isostatic pressing treatment, the isostatic pressing pressure is 400 MPa, the isostatic pressing temperature is 60° C., and the isostatic pressing time is 10 min;

[0124] Further, the sealing bag on the composite structure of the positive electrode / electrolyte membrane / negative electrode after isostatic pressing is disassembled to obtain a unit battery cell 20 that is shaped like the clamping bin of the second special-shaped fixture 6, and 5 pcs of unit battery cells 20 are stacked, the tabs are welded, and the aluminum-plastic film is encapsulated to obtain a special-shaped all-solid-state battery;

[0125] Finally, the prepared special-shaped all-solid-state battery was subjected to a pressurized charge and discharge test, with a charge cut-off voltage of 4.2V and a discharge cut-off voltage of 2.8V, to test the battery coulombic efficiency and cycle performance.

[0126] In the above embodiments, the pressurized charge and discharge test of the special-shaped all-solid-state battery is carried out to test the first coulombic efficiency and cycle performance of the battery. The specific test statistical results are shown in Table 1.

[0127] Table 1:

[0128]

[0129]

[0130] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0131] The present application adopts a method of performing a first isostatic pressing treatment on the electrolyte membrane / negative electrode composite structure in the first special-shaped clamp 4 to obtain an electrolyte membrane / negative electrode composite electrode sheet 10 that is shaped like the clamping bin of the first special-shaped clamp 4; and by using the second special-shaped clamp 6 to perform a second isostatic pressing on the positive electrode sheet 3 and the electrolyte membrane / negative electrode composite electrode sheet 10, a unit battery cell 20 that is shaped like the clamping bin of the first special-shaped clamp 4 is obtained. Since the first special-shaped clamp 4 and the second special-shaped clamp 6 have simple structures, the preparation process of the special-shaped unit battery cell 20 is simple and efficient. At the same time, by correspondingly arranging the first permeation layer 5 and the second permeation layer 7 in the first special-shaped clamp 4 and the inside of the first special-shaped clamp 4, it can While maintaining the shape of the unit battery cell 20 and the electrolyte membrane / negative electrode composite plate 10, isostatic pressing liquid is allowed to penetrate, thereby improving the isostatic pressing effect. The material cost of the first permeation layer 5 and the second permeation layer 7 is low, which can reduce the preparation cost of the battery cell; and the unit battery cell 20 and the electrolyte membrane / negative electrode composite plate 10 obtained after isostatic pressing are highly compatible with the stacking process and equipment in the industry, and are convenient for mass production; at the same time, it can be seen from the test statistical results that the first coulomb efficiency of the special-shaped all-solid-state battery prepared by using the first special-shaped clamp 4 and the second special-shaped clamp 6 is above 80%, and the capacity retention rate after 400 cycles is above 85%, which meets the electrochemical performance requirements of the battery test.

[0132] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0133] It should be noted that all the features recorded in the present invention (including technical features recorded in different embodiments) can be combined arbitrarily under reasonable circumstances, and new technical solutions formed by the combination are all within the protection scope of the present invention.

[0134] What is described above are only some embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art should understand that the present invention may be subject to various changes and improvements, and any modifications, equivalent substitutions and improvements made in accordance with the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A method for preparing a special-shaped solid-state unit battery cell, characterized in that: The following steps are involved: S1: fixing the electrolyte membrane on both sides of the negative electrode plate to obtain an electrolyte membrane / negative electrode composite structure, and placing the electrolyte membrane / negative electrode composite structure into a first special-shaped fixture; S2: performing a first isostatic pressing process on the first special-shaped fixture carrying the composite structure of the electrolyte membrane / negative electrode; S3: After the first isostatic pressing treatment, an electrolyte membrane / negative electrode composite electrode sheet conforming to the clamping chamber of the first special-shaped clamp is obtained; S4: fixing the positive electrode sheet on both sides of the electrolyte membrane / negative electrode composite sheet to obtain a positive electrode / electrolyte membrane / negative electrode composite structure, and placing the positive electrode / electrolyte membrane / negative electrode composite structure into a second special-shaped fixture; S5: performing a second isostatic pressing process on the second special-shaped fixture carrying the composite structure of the positive electrode / electrolyte membrane / negative electrode; S6: After the second isostatic pressing treatment, a unit cell having a shape similar to the clamping bin of the second anisotropic clamp is obtained.

2. The method for preparing a special-shaped solid-state unit battery cell according to claim 1, characterized in that: The solid electrolyte in the electrolyte membrane is a sulfide solid electrolyte, a halide solid electrolyte or a composite electrolyte of sulfide and halide.

3. The method for preparing a special-shaped solid-state unit battery cell according to claim 1, characterized in that: The first isostatic pressing treatment satisfies at least one of the following characteristics: Isostatic pressure is 50~500MPa; Isostatic pressing temperature is 20-120°C; The isostatic pressing time is 1 to 500 minutes.

4. The method for preparing a special-shaped solid-state unit battery cell according to claim 1, characterized in that: The second isostatic pressing treatment satisfies at least one of the following characteristics: Isostatic pressure is 100~600MPa; Isostatic pressing temperature is 20-120°C; The isostatic pressing time is 1 to 500 minutes.

5. The method for preparing a special-shaped solid-state unit battery cell according to any one of claims 1 to 4, characterized in that: The clamping bin of the first special-shaped clamp and the clamping bin of the second special-shaped clamp have the same shape.

6. The method for preparing a special-shaped solid-state unit battery cell according to claim 5, characterized in that: The first special-shaped fixture and the second special-shaped fixture satisfy at least one of the following: The clamping compartment of the first special-shaped clamp is provided with a first permeable layer, and the first permeable layer is used to fit with two side surfaces of the composite structure of the electrolyte membrane / negative electrode; A second permeable layer is disposed inside the second special-shaped fixture, and the second permeable layer is bonded to two side surfaces of the composite structure of the positive electrode / electrolyte membrane / negative electrode.

7. The method for preparing a special-shaped solid-state unit battery cell according to claim 6, characterized in that: The first permeable layer and the second permeable layer satisfy at least one of the following: The first permeable layer comprises at least one of non-woven fabric, foam and sponge; The second permeable layer includes at least one of non-woven fabric, foam and sponge.

8. The method for preparing a special-shaped solid-state unit battery cell according to claim 7, characterized in that: The preparation method satisfies at least one of the following: The thickness of the first permeable layer is 0.1 to 1 mm; The thickness of the second permeable layer is 0.1 to 1 mm; The curvature of the positive electrode sheet is 0 to 20 degrees; The bending curvature of the negative electrode plate is 0-20.

9. A special-shaped solid-state cell, characterized in that: The special-shaped solid-state unit battery cell is prepared by the preparation method described in any one of claims 1-8.

10. A special-shaped all-solid-state battery, which is obtained by stacking a plurality of special-shaped solid-state unit core layers, connecting the pole ears in parallel, and finally welding the pole ears and packaging to obtain the special-shaped solid-state battery, characterized in that: The special-shaped solid-state unit battery core layer is the special-shaped solid-state unit battery core according to claim 9.

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