Isostatic pressing device of all-solid-state battery and preparation method of all-solid-state battery

Abstract

The invention discloses an isostatic pressing device of an all-solid-state battery and a preparation method of the all-solid-state battery, the isostatic pressing device of the all-solid-state battery comprises a shell with an opening at the upper end and an upper cover, an isostatic pressing cavity is formed in the shell, the upper cover covers the upper end of the shell, a cylinder is arranged in the isostatic pressing cavity, and the upper cover covers the upper end of the shell. An all-solid-state battery and a conductive connecting piece used for being electrically connected with a tab of the all-solid-state battery are placed in the cylinder body, the cylinder body comprises a left half part, an insulating parting strip and a right half part, the left half part, the insulating parting strip and the right half part are sequentially connected, the left half part is electrically connected with the upper cover, and the insulating parting strip is electrically connected with the conductive connecting piece. The left half part is electrically connected with the shell, the right half part is electrically connected with the shell, an insulating sealing ring is arranged between the shell and the upper cover, and a tab of the all-solid-state battery is electrically connected with the left half part or the right half part through the conductive connecting piece; the device has the advantages that the isostatic pressing function and the in-situ formation function are achieved, the preparation process is shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of all-solid-state battery production equipment, and in particular relates to an isostatic pressing device for an all-solid-state battery and a method for preparing the all-solid-state battery. Background Art

[0002] As a new generation of battery technology, all-solid-state batteries offer advantages such as high energy density, long cycle life, and high safety, but they also suffer from issues such as insufficient density and poor contact between the electrode and electrolyte interfaces. To address this, those skilled in the art have developed an isostatic pressing device for all-solid-state batteries. This device is specifically designed for isostatic pressing battery materials or battery components. The device aims to improve the density, interface contact, and overall performance of battery materials, playing a vital role in the battery manufacturing process.

[0003] A conventional isostatic pressing device includes a container and a tray set inside the container. During operation, the worker places an all-solid-state battery on the tray, then closes the container and starts the device to fill the container with a high-pressure medium. The high-pressure medium acts evenly on all sides of the all-solid-state battery. After maintaining the pressure for a period of time, the pressure is released. Finally, the container is opened and the all-solid-state battery is taken out. It can be seen that the conventional isostatic pressing device has a single function. After the isostatic pressing treatment, the all-solid-state battery still needs to be in-situ formed. There are many preparation steps, resulting in low production efficiency. Therefore, it is particularly important to develop an isostatic pressing device that can combine the functions of isostatic pressing and in-situ formation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an isostatic pressing device for an all-solid-state battery and a method for preparing an all-solid-state battery. The isostatic pressing device for an all-solid-state battery has both isostatic pressing function and in-situ formation function, which helps to shorten the preparation process and improve production efficiency.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: an isostatic pressing device for an all-solid-state battery, comprising a shell with an open upper end and an upper cover, an isostatic pressing chamber formed in the shell, the upper cover is covered on the upper end of the shell, a cylinder is provided in the isostatic pressing chamber, an all-solid-state battery and a conductive connector for electrically connecting to the pole tab of the all-solid-state battery are placed in the cylinder, the cylinder comprises a left half, an insulating spacer and a right half, the left half, the insulating spacer and the right half are connected in sequence, the left half is electrically connected to the upper cover, the right half is electrically connected to the shell, an insulating sealing ring is provided between the shell and the upper cover, and the pole tab of the all-solid-state battery is electrically connected to the left half or the right half through the conductive connector.

[0006] Preferably, the conductive connector includes two clamps, the left half is electrically connected to one pole ear of the all-solid-state battery through one clamp, and the right half is electrically connected to the other pole ear of the all-solid-state battery through the other clamp, and the clamp includes a wire and a conductive clamp, one end of the wire is electrically connected to the left half or the right half, and the other end of the wire is connected to the conductive clamp, and the conductive clamp is used to clamp the pole ear of the all-solid-state battery.

[0007] Preferably, the conductive chuck includes a mounting plate, two side plates are integrally provided on the mounting plate, a clamping space is formed between the two side plates, a screw hole and a bolt are provided on one of the side plates, the pole ear of the all-solid-state battery extends into the clamping space, and the bolt passes through the screw hole and cooperates with the other side plate to clamp the pole ear of the all-solid-state battery.

[0008] Preferably, there are multiple cylinders, and the multiple cylinders are distributed in the up and down directions. All the left halves are stacked in sequence from bottom to top, and all the right halves are stacked in sequence from bottom to top. The left half located at the top layer is electrically connected to the upper cover, and the right half located at the bottom layer is electrically connected to the shell.

[0009] Preferably, the lower end surface of the cylinder is provided with a plurality of positioning grooves, and the upper end of the cylinder is provided with a plurality of positioning blocks, and the positioning blocks on the lower side of the cylinder are inserted into the positioning grooves on the upper side of the cylinder.

[0010] Preferably, a first insulating layer is provided between the cylinder located at the top layer and the upper cover, a first through hole and a first conductive member are provided on the first insulating layer, and the left half is electrically connected to the upper cover through the first conductive member; a second insulating layer is provided between the cylinder located at the bottom layer and the shell, a second through hole and a second conductive member are provided on the second insulating layer, and the right half is electrically connected to the inner bottom surface of the shell through the second conductive member.

[0011] Preferably, the side surface of the left half is provided with a plurality of first perforations, and the side surface of the right half is provided with a plurality of second perforations, and the plurality of first perforations and the plurality of second perforations correspond to each other one by one and are symmetrically distributed on the left and right sides; the conductive connector also includes a hinge structure that can be opened 180°, and the hinge structure includes a left blade and a right blade, and the right side of the left blade is rotatably connected to the left side of the right blade through a connecting shaft, and conductive rods are respectively fixedly provided on the left side of the left blade and the right side of the right blade, and the conductive rods are plugged into and matched with the first perforation or the second perforation, and one end of the wire is connected to a conductive ring, and the conductive ring is sleeved on the conductive rod.

[0012] Preferably, a sleeve and a connecting rod that slides with the sleeve is provided on the left blade or the right blade, and a laterally extending limit rod is fixedly provided at one end of the connecting rod away from the sleeve, and the limit rod is used to be plugged into and engaged with the first perforation or the second perforation.

[0013] Preferably, a tension spring is provided between the inner bottom surface of the sleeve and the connecting rod, and the tension spring is used to drive the connecting rod close to the sleeve. A baffle is fixedly provided on the side of the limiting rod, and the baffle is located between the limiting rod and the conductive rod. A limiting space is formed between the baffle and the sleeve, and the conductive ring is located in the limiting space.

[0014] And a method for preparing an all-solid-state battery, using the above-mentioned isostatic pressing device for the all-solid-state battery, comprising the following steps:

[0015] S1. Place the all-solid-state battery into the cylinder;

[0016] S2. One tab of the all-solid-state battery is electrically connected to the left half through a conductive connector, and the other tab of the all-solid-state battery is electrically connected to the right half through a conductive connector;

[0017] S3. Place the cylinder into the isostatic pressure chamber of the shell, cover it with the upper cover, and electrically connect the left half to the upper cover and the right half to the shell;

[0018] S4, connect an external power supply so that the power supply, housing, all-solid-state battery and upper cover form a closed circuit;

[0019] S5. Set the temperature and pressure parameters, start the isostatic pressing device, inject high-pressure medium into the isostatic pressing chamber, and uniformly apply the high-pressure medium to all surfaces of the all-solid-state battery, and maintain the pressure for a period of time;

[0020] S6. During the pressure holding process, turn on the power supply to perform in-situ formation of the all-solid-state battery;

[0021] S7. After the in-situ formation is completed, turn off the power supply, release the high-voltage medium, and remove the cylinder and the all-solid-state battery.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] 1. By arranging a cylinder and a conductive connector in the isostatic pressing chamber, the cylinder includes a left half, an insulating spacer and a right half. The tabs of the all-solid-state battery are electrically connected to the left half or the right half through the conductive connector. During the isostatic pressing process, the all-solid-state battery can be powered by an external power supply and then undergo in-situ formation, which helps shorten the preparation process and improve the production efficiency of the all-solid-state battery.

[0024] 2. Compared with conventional in-situ formation, the in-situ formation of all-solid-state batteries under high pressure can achieve closer contact between the electrolyte and the electrode, forming a stable and complete solid electrolyte interface (SEI film), significantly improving the active material utilization and interface compatibility of the all-solid-state battery, and ultimately improving the later cycle performance and specific capacity of the all-solid-state battery, that is, improving the performance of the all-solid-state battery;

[0025] 3. This technical solution is also suitable for testing the cycle performance of all-solid-state batteries under high pressure and has good applicability;

[0026] 4. By setting up multiple stacked cylinders in the isostatic pressing chamber, each cylinder contains an all-solid-state battery. Each operation can process multiple all-solid-state batteries at one time, greatly improving processing efficiency, shortening production cycle, and helping to increase output;

[0027] 5. Parallel processing of multiple all-solid-state batteries can reduce the frequency of workers opening and closing the upper cover, which helps to further shorten the processing time of all-solid-state batteries;

[0028] 6. The stacking design of the cylinders rationally utilizes the space of the isostatic pressure chamber, making the volume of the entire device compact, while ensuring the independent processing space of each all-solid-state battery and avoiding interference between all-solid-state batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a schematic diagram of the explosion structure of the present invention;

[0031] Figure 3 The structure of the cylinder in the present invention is shown in FIG. Figure 1 ;

[0032] Figure 4 Schematic diagram of the structure of the conductive connector in the present invention;

[0033] Figure 5 Schematic diagram of circuit connection in the present invention;

[0034] Figure 6 The structure of the cylinder in the present invention is shown in FIG. Figure 2 ;

[0035] Figure 7 It is a schematic diagram of the cross-sectional structure of the present invention;

[0036] Figure 8 for Figure 7 A magnified schematic diagram of point A in the middle;

[0037] Figure 9 for Figure 7A magnified schematic diagram of point B in the middle;

[0038] Figure 10 The structure of the cylinder in the present invention is shown in FIG. Figure 3 ;

[0039] Figure 11 Schematic diagram of the cross-sectional structure of the cylinder in the present invention;

[0040] Figure 12 for Figure 11 The enlarged schematic diagram of point C in the middle;

[0041] Figure 13 Schematic diagram of the exploded structure of the conductive connector in the present invention;

[0042] Figure 14 1 is the cycle life curve of the all-solid-state battery of Example 6 and Comparative Example 1;

[0043] Figure 15 The charge and discharge curves of the all-solid-state batteries of Example 6 and Comparative Example 1 formed in situ.

[0044] In the figure: 1, shell; 11, isostatic chamber; 2, upper cover; 3, cylinder; 31, left half; 311, first through-hole; 32, insulating spacer; 33, right half; 331, second through-hole; 34, positioning groove; 35, positioning block; 4, all-solid-state battery; 5, fixture; 51, wire; 52, conductive clamp; 521, mounting plate; 522, side plate; 523, screw hole; 524, bolt; 53 , conductive ring; 6, insulating sealing ring; 7, first insulating layer; 71, first through hole; 72, first conductive part; 8, second insulating layer; 81, second through hole; 82, second conductive part; 9, hinge structure; 91, left blade; 911, limiting groove; 92, right blade; 921, limiting plate; 93, conductive rod; 94, sleeve; 95, connecting rod; 96, limiting rod; 97, tension spring; 98, baffle. DETAILED DESCRIPTION

[0045] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0046] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] Example 1: Figures 1 to 3 As shown, an isostatic pressing device for an all-solid-state battery includes a shell 1 with an open upper end and an upper cover 2. An isostatic pressing chamber 11 is formed in the shell 1, and the upper cover 2 is covered on the upper end of the shell 1 to close the isostatic pressing chamber 11.

[0048] In this embodiment, a cylinder 3 is disposed within the isostatic pressure chamber 11. The lower end of the cylinder 3 is closed, the upper end of the cylinder 3 is open, and the side of the cylinder 3 is provided with several perforations. An all-solid-state battery 4 and a conductive connector for electrically connecting the tabs of the all-solid-state battery 4 are placed within the cylinder 3. During the preparation process, the high-pressure medium within the isostatic pressure chamber 11 can flow into the cylinder 3 through the perforations and fill the area surrounding the all-solid-state battery 4. Furthermore, the cylinder 3 includes a left half 31, an insulating spacer 32, and a right half 33. The left half 31, insulating spacer 32, and right half 33 are sequentially connected. The left half 31 is electrically connected to the upper cover 2, and the right half 33 is electrically connected to the housing 1. An insulating sealing ring 6 is disposed between the housing 1 and the upper cover 2. The provision of the insulating sealing ring 6 prevents short circuits between the housing 1 and the upper cover 2. The tabs of the all-solid-state battery 4 are electrically connected to the left half 31 or the right half 33 via the conductive connector.

[0049] It should be noted that in this solution, the shell 1, upper cover 2, left half 31, and right half 33 are all made of conductive materials. A power interface (not shown in the figure) is set on the shell 1 and the upper cover 2 to facilitate external power supply. The high-voltage medium is non-conductive.

[0050] Accordingly, the method for preparing an all-solid-state battery using the isostatic pressing device of the all-solid-state battery comprises the following steps:

[0051] S1. Place the all-solid-state battery 4 into the cylinder 3;

[0052] S2. One tab of the all-solid-state battery 4 is electrically connected to the left half 31 through a conductive connector, and the other tab of the all-solid-state battery 4 is electrically connected to the right half 33 through a conductive connector;

[0053] S3. Place the cylinder 3 into the isostatic chamber 11 of the housing 1 and cover it with the upper cover 2, so that the left half 31 is electrically connected to the upper cover 2 and the right half 33 is electrically connected to the housing 1;

[0054] S4, connect an external power supply so that the power supply, housing 1, all-solid-state battery 4 and upper cover 2 form a closed circuit;

[0055] S5. Set the temperature and pressure parameters, start the isostatic pressing device, and inject high-pressure medium into the isostatic pressing chamber 11. The high-pressure medium acts evenly on all surfaces of the all-solid-state battery 4 and maintains the pressure for a period of time.

[0056] S6. During the pressure maintenance process, turn on the power supply to perform in-situ formation on the all-solid-state battery 4;

[0057] S7. After the in-situ formation is completed, turn off the power supply, release the high-voltage medium, and take out the cylinder 3 and the all-solid-state battery 4.

[0058] It should be noted that this technical solution can also replace the power supply with a charge and discharge test device to test the cycle performance of all-solid-state batteries under high pressure.

[0059] Example 2: Figure 3 and Figure 4 As shown, the rest of the parts are the same as those in Example 1, except that the conductive connector includes two clamps 5, the left half 31 is electrically connected to one pole ear of the all-solid-state battery 4 through one clamp 5, and the right half 33 is electrically connected to the other pole ear of the all-solid-state battery 4 through another clamp 5.

[0060] In this embodiment, the clamp 5 includes a wire 51 and a conductive clamp 52. One end of the wire 51 is electrically connected to the left half 31 or the right half 33, and the other end of the wire 51 is connected to the conductive clamp 52. The conductive clamp 52 is used to clamp the pole ear of the all-solid-state battery 4. Furthermore, the conductive clamp 52 includes a mounting plate 521. Two side plates 522 are integrally provided on the mounting plate 521. A clamping space is formed between the two side plates 522. A screw hole 523 and a bolt 524 are provided on one side plate 522. The pole ear of the all-solid-state battery 4 extends into the clamping space. After the bolt 524 passes through the screw hole 523, it cooperates with the other side plate 522 to clamp the pole ear of the all-solid-state battery 4. The structure is simple, easy to operate, and the clamping stability is good.

[0061] During the isostatic pressing process, the all-solid-state battery 4 is connected to an external power source, such as the positive electrode of the all-solid-state battery 4 is led out through the fixture 5, the left half 31, and the upper cover 2, and the negative electrode of the all-solid-state battery 4 is led out through the fixture 5, the right half 33, and the shell 1, to achieve the power supply function (see Figure 5 ), capable of in-situ formation.

[0062] Example 3: Figure 2 、 Figure 3 and Figure 6 As shown, the rest of the structure is the same as that of the first embodiment, except that multiple cylinders 3 are provided, and the multiple cylinders 3 are distributed in the vertical direction. All left halves 31 are stacked sequentially from bottom to top, and all right halves 33 are stacked sequentially from bottom to top. The left half 31 located on the top layer is electrically connected to the upper cover 2, and the right half 33 located on the bottom layer is electrically connected to the housing 1. Since the space within each cylinder 3 is independent, that is, the all-solid-state batteries 4 in different cylinders 3 do not interfere with each other, multiple all-solid-state batteries 4 can be processed at one time in each operation, greatly improving processing efficiency.

[0063] In this embodiment, the lower end surface of the cylinder 3 is provided with a plurality of positioning grooves 34, and the upper end of the cylinder 3 is provided with a plurality of positioning blocks 35. The positioning blocks 35 on the lower cylinder 3 are inserted into the positioning grooves 34 on the upper cylinder 3. The addition of the positioning grooves 34 and positioning blocks 35 helps to improve the stability of the stacking of the cylinders 3. Furthermore, the lower end surface of the left half 31 is provided with a positioning groove 34, the upper end surface of the left half 31 is provided with a positioning block 35, the lower end surface of the right half 33 is provided with two positioning grooves 34, and the upper end surface of the right half 33 is provided with two positioning blocks 35. The number of positioning grooves 34 on the left half 31 and the number of positioning blocks 35 on the right half 33 are different, which has a fool-proof effect and prevents workers from misplacing the stacking, thereby improving safety.

[0064] Example 4: Figures 7 to 9 As shown, the rest of the structure is the same as that of Example 3, except that a first insulating layer 7 is provided between the uppermost cylinder 3 and the upper cover 2. The first insulating layer 7 is provided with a first through-hole 71 and a first conductive member 72, and the left half 31 is electrically connected to the upper cover 2 via the first conductive member 72. A second insulating layer 8 is provided between the lowermost cylinder 3 and the housing 1. The second insulating layer 8 is provided with a second through-hole 81 and a second conductive member 82, and the right half 33 is electrically connected to the inner bottom surface of the housing 1 via the second conductive member 82. The provision of the first insulating layer 7 and the second insulating layer 8 can prevent the positive and negative electrodes from directly contacting each other and causing a short circuit, thereby reducing the risk of failure.

[0065] Preferably, the first conductive member 72 and the second conductive member 82 are conductive springs, which have the advantages of good electrical conductivity, excellent mechanical properties, strong adaptability, and high durability, ensuring stable and continuous electrical connection between the left half 31 and the upper cover 2, and between the right half 33 and the housing 1. Of course, the first conductive member 72 and the second conductive member 82 can also be conductive metal rods.

[0066] During actual operation, the all-solid-state battery 4 is first placed in the cylinder 3, and the positive and negative electrodes of the all-solid-state battery 4 are fixed. Then the cylinder 3 is stacked in the isostatic pressing chamber 11, and the isostatic pressing chamber 11 is closed by the upper cover 2. Then, the external power supply is connected, the appropriate temperature and pressure parameters are set, and the isostatic pressing equipment is started. During the warm isostatic pressing process, the all-solid-state battery 4 is subjected to uniform pressure and temperature, and at the same time, in-situ formation is achieved to generate a stable and complete SEI film, which helps to improve the utilization rate of the battery's active materials and interface compatibility.

[0067] It should be noted that the above-mentioned insulating spacers 32, insulating sealing rings 6, first insulating layers 7, and second insulating layers 8 can be made of common insulating materials on the market, such as glass fiber reinforced plastic (GRP), silicone rubber, fiber reinforced plastic (FRP), polyethylene, polyvinyl chloride, polypropylene, ceramics, glass, polymer composite materials, etc. The specific selection depends on the use environment and will not be elaborated here.

[0068] Example 5: Figures 10 to 13 As shown, the rest of the parts are the same as those in the second embodiment, except that a plurality of first perforations 311 are provided on the side of the left half 31, and a plurality of second perforations 331 are provided on the side of the right half 33. The plurality of first perforations 311 and the plurality of second perforations 331 correspond to each other one by one and are symmetrically distributed on the left and right.

[0069] In this embodiment, the conductive connector also includes a hinge structure 9 that can be opened 180°. The hinge structure 9 includes a left blade 91 and a right blade 92. The right side of the left blade 91 is rotatably connected to the left side of the right blade 92 by a connecting shaft. A conductive rod 93 is fixedly provided on the left side of the left blade 91 and the right side of the right blade 92 respectively. The conductive rod 93 is plugged into the first through-hole 311 or the second through-hole 331. One end of the wire 51 is connected to a conductive ring 53, which is sleeved on the conductive rod 93. By setting the conductive ring 53, in actual use, one or two conductive rings 53 can be sleeved on the conductive rod 93 so that one or two clamps 5 can be extended from one conductive rod 93. When there is one clamp 5, the clamp 5 is used in conjunction with the all-solid-state battery 4 located above or below the hinge structure 9. When there are two clamps 5, the two clamps 5 correspond one-to-one to the all-solid-state batteries 4 located above and below the hinge structure 9 and are used in conjunction with each other so as to be flexibly used. Among them, a limiting groove 911 is set on the right side of the left blade 91, and the upper end of the limiting groove 911 passes through the upper end surface of the left blade 91. A limiting plate 921 is integrally provided on the left side of the right blade 92. The limiting groove 911 and the limiting plate 921 are both located above the connecting axis. When the hinge structure 9 is unfolded, the left blade 91 and the right blade 92 are located on the same plane, and the limiting plate 921 extends into the limiting groove 911 to limit the maximum unfolding angle (180°) of the hinge structure 9, avoid excessive unfolding, and have better stability.

[0070] By adding a hinge structure 9, the cylinder 3 can be divided into two independent upper and lower chambers, each of which can be used to accommodate an all-solid-state battery 4, so as to improve the applicability of the cylinder 3. In addition, the insertion of the hinge structure 9 is relatively simple. It flexibly cooperates with the first through-hole 311 on the left half 31 and the second through-hole 331 on the right half 33 through the conductive rod 93, thereby flexibly adjusting the spatial distribution inside the cylinder 3 to be suitable for all-solid-state batteries 4 of different sizes. Of course, at this time, multiple conductive connectors can be provided, and multiple conductive connectors can divide the cylinder 3 into multiple independent chambers to be suitable for multiple all-solid-state batteries 4, which will greatly improve the applicability.

[0071] In this embodiment, both the left and right blades 91 and 92 are provided with sleeves 94 and connecting rods 95 that slidably engage with the sleeves 94. A laterally extending stopper 96 is fixedly mounted on one end of the connecting rod 95, distal from the sleeves 94. The stopper 96 is configured to engage with the first through-hole 311 or the second through-hole 331. In this embodiment, the conductive rod 93 not only provides electrical connection but also cooperates with the stopper 96 to prevent the hinge structure 9 from rotating, thereby improving the structural stability.

[0072] Furthermore, a tension spring 97 is provided between the inner bottom surface of the sleeve 94 and the connecting rod 95. The tension spring 97 is used to force the connecting rod 95 toward the sleeve 94. A baffle 98 is fixedly provided on the side of the limiting rod 96. The baffle 98 is positioned between the limiting rod 96 and the conductive rod 93. A limiting space is formed between the baffle 98 and the sleeve 94, and the conductive ring 53 is positioned within the limiting space. When the conductive rod 93 and the limiting rod 96 are plugged into the two first through-holes 311 or the two second through-holes 331, the tension spring 97 stretches and generates a rebound force, which ensures that the conductive rod 93 is in close contact with the left half 31 or the right half 33, thus ensuring the stability of the electrical connection. At the same time, the baffle 98 moves with the connecting rod 95 and the limiting rod 96 to open or close the limiting space. When the limiting space is opened, the staff can install the conductive ring 53. When the limiting space is closed, the conductive ring 53 can be prevented from separating from the conductive rod 93, thus improving stability.

[0073] It should be noted that the left blade 91 and the right blade 92 are made of insulating material.

[0074] Example 6: Using LiNi as the positive electrode x Mn y Co z Taking an all-solid-state battery composed of O2[NMC], sulfide electrolyte, and silicon-based negative electrode as an example, the isostatic pressing device of the all-solid-state battery disclosed in Example 1 is used for isostatic pressing treatment. After the all-solid-state battery is placed in the isostatic pressing chamber, the temperature is set to 50°C, the pressure is set to 400 MPa, the isostatic pressing device is started, and after isostatic pressing for 0.5 h, power is turned on for in-situ formation, specifically, charging at a rate of 0.1C for 10 h, and then discharging at a rate of 0.1C for 10 h, for one cycle. After the in-situ formation is completed, the all-solid-state battery is taken out.

[0075] Comparative Example 1: Compared to Example 6, the same all-solid-state battery was used. After the all-solid-state battery was placed in the isostatic pressing chamber, the temperature was set to 50°C and the pressure was set to 400 MPa. The isostatic pressing device was started. After isostatic pressing for 0.5 hours, the all-solid-state battery was removed and transferred to the formation station. After connecting the conductive fixture, power was applied for in-situ formation. Specifically, the battery was charged at a rate of 0.1C for 10 hours and then discharged at a rate of 0.1C for 10 hours, for one cycle. The transfer process of the all-solid-state battery is expected to take 0.5 hours.

[0076] The all-solid-state batteries obtained in Example 6 and Comparative Example 1 were subjected to charge and discharge cycle tests. The battery was charged to 4.2 V at a rate of 0.5 C, and then discharged to 2.6 V at a rate of 0.5 C. The specific capacity and the number of cycles when the specific capacity dropped to 80% were recorded. The results are shown in the following tables and Figure 14 As shown:

[0077] Isostatic pressing and in-situ forming time (h) Initial specific capacity (mAh / g) Number of cycles when the specific capacity drops to 80% Example 6 20h 112 668 Comparative Example 1 21h 96.2 77

[0078] As shown in the table above, compared with conventional isostatic pressing and in-situ formation, the preparation time can be shortened by approximately 4.8%, the initial specific capacity of the all-solid-state battery can be increased by approximately 16.4%, and the number of cycles can be increased by approximately 767.5%. This shows that this technical solution can play an important role in improving the preparation process and performance of all-solid-state batteries.

[0079] For further information, see Figure 15 , are the charge and discharge curves of the all-solid-state batteries of Example 6 and Comparative Example 1 in situ formation. It can be seen from the figure that the first efficiency of the all-solid-state battery of Example 6 reaches 92.4%, while the first efficiency of the all-solid-state battery of Comparative Example 1 is only 82.7%. It can be seen that in situ formation is carried out during the isostatic pressing process, the pressure is relatively high, and the contact between the electrolyte and the electrode of the all-solid-state battery will be closer, which can form a stable and complete solid electrolyte interface (SEI film), significantly improving the active material utilization and interface compatibility of the all-solid-state battery, and ultimately improving the later cycle performance and specific capacity of the all-solid-state battery, that is, improving the performance of the all-solid-state battery.

[0080] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. An isostatic pressing device for an all-solid-state battery, comprising a shell (1) with an open upper end and an upper cover (2), wherein an isostatic pressing chamber (11) is formed in the shell (1), and the upper cover (2) covers the upper end of the shell (1), characterized in that: A cylinder (3) is provided in the isostatic chamber (11), and an all-solid-state battery (4) and a conductive connector for electrically connecting to the tab of the all-solid-state battery (4) are placed in the cylinder (3). The cylinder (3) includes a left half (31), an insulating spacer (32) and a right half (33). The left half (31), the insulating spacer (32) and the right half (33) are connected in sequence. The left half (31) is electrically connected to the upper cover (2), and the right half (33) is electrically connected to the shell (1). An insulating sealing ring (6) is provided between the shell (1) and the upper cover (2). The tab of the all-solid-state battery (4) is electrically connected to the left half (31) or the right half (33) through the conductive connector.

2. The isostatic pressing device for an all-solid-state battery according to claim 1, characterized in that: The conductive connector includes two clamps (5), the left half (31) is electrically connected to one pole tab of the all-solid-state battery (4) through one clamp (5), and the right half (33) is electrically connected to the other pole tab of the all-solid-state battery (4) through the other clamp (5), the clamp (5) includes a wire (51) and a conductive clamp (52), one end of the wire (51) is electrically connected to the left half (31) or the right half (33), and the other end of the wire (51) is connected to the conductive clamp (52), and the conductive clamp (52) is used to clamp the pole tab of the all-solid-state battery (4).

3. The isostatic pressing device for an all-solid-state battery according to claim 2, characterized in that: The conductive clamp (52) includes a mounting plate (521), two side plates (522) are integrally provided on the mounting plate (521), a clamping space is formed between the two side plates (522), a screw hole (523) and a bolt (524) are provided on one of the side plates (522), the pole ear of the all-solid-state battery (4) extends into the clamping space, and the bolt (524) passes through the screw hole (523) and cooperates with the other side plate (522) to clamp the pole ear of the all-solid-state battery (4).

4. The isostatic pressing device for an all-solid-state battery according to claim 1, characterized in that: The cylinders (3) are provided in plurality and are distributed in the vertical direction. All the left halves (31) are stacked in sequence from bottom to top, and all the right halves (33) are stacked in sequence from bottom to top. The left half (31) located in the uppermost layer is electrically connected to the upper cover (2), and the right half (33) located in the lowermost layer is electrically connected to the shell (1).

5. The isostatic pressing device for an all-solid-state battery according to claim 4, characterized in that: The lower end surface of the cylinder (3) is provided with a plurality of positioning grooves (34), and the upper end of the cylinder (3) is provided with a plurality of positioning blocks (35). The positioning blocks (35) on the lower side of the cylinder (3) are inserted into the positioning grooves (34) on the upper side of the cylinder (3).

6. The isostatic pressing device for an all-solid-state battery according to claim 4, characterized in that: A first insulating layer (7) is provided between the uppermost cylinder (3) and the upper cover (2); a first through hole (71) and a first conductive member (72) are provided on the first insulating layer (7); and the left half (31) is electrically connected to the upper cover (2) via the first conductive member (72); A second insulating layer (8) is provided between the cylinder (3) located at the bottom layer and the shell (1); a second through hole (81) and a second conductive member (82) are provided on the second insulating layer (8); and the right half (33) is electrically connected to the inner bottom surface of the shell (1) through the second conductive member (82).

7. The isostatic pressing device for an all-solid-state battery according to claim 2, characterized in that: The side surface of the left half (31) is provided with a plurality of first perforations (311), and the side surface of the right half (33) is provided with a plurality of second perforations (331), wherein the plurality of first perforations (311) and the plurality of second perforations (331) correspond to each other one by one and are symmetrically distributed on the left and right sides; The conductive connecting member further comprises a hinge structure (9) that can be opened 180 degrees, the hinge structure (9) comprising a left blade (91) and a right blade (92), the right side of the left blade (91) being rotatably connected to the left side of the right blade (92) via a connecting shaft, a conductive rod (93) being fixedly provided on the left side of the left blade (91) and the right side of the right blade (92), respectively, the conductive rod (93) being plugged into and matched with the first through-hole (311) or the second through-hole (331), one end of the electric wire (51) being connected to a conductive ring (53), the conductive ring (53) being sleeved on the conductive rod (93).

8. The isostatic pressing device for an all-solid-state battery according to claim 7, characterized in that: The left blade (91) or the right blade (92) is provided with a sleeve (94) and a connecting rod (95) that is slidably engaged with the sleeve (94); a laterally extending limiting rod (96) is fixedly provided at one end of the connecting rod (95) away from the sleeve (94); the limiting rod (96) is used to be plugged into and engaged with the first through-hole (311) or the second through-hole (331).

9. The isostatic pressing device for an all-solid-state battery according to claim 8, characterized in that: A tension spring (97) is provided between the inner bottom surface of the sleeve (94) and the connecting rod (95), and the tension spring (97) is used to drive the connecting rod (95) close to the sleeve (94). A baffle (98) is fixedly provided on the side of the limiting rod (96), and the baffle (98) is located between the limiting rod (96) and the conductive rod (93). A limiting space is formed between the baffle (98) and the sleeve (94), and the conductive ring (53) is located in the limiting space.

10. A method for preparing an all-solid-state battery, characterized in that: The isostatic pressing device for the all-solid-state battery according to claim 1 comprises the following steps: S1. Place the all-solid-state battery into the cylinder; S2. One tab of the all-solid-state battery is electrically connected to the left half through a conductive connector, and the other tab of the all-solid-state battery is electrically connected to the right half through a conductive connector; S3. Place the cylinder into the isostatic pressure chamber of the shell, cover it with the upper cover, and electrically connect the left half to the upper cover and the right half to the shell; S4, connect an external power supply so that the power supply, housing, all-solid-state battery and upper cover form a closed circuit; S5. Set the temperature and pressure parameters, start the isostatic pressing device, inject high-pressure medium into the isostatic pressing chamber, and uniformly apply the high-pressure medium to all surfaces of the all-solid-state battery, and maintain the pressure for a period of time; S6. During the pressure holding process, turn on the power supply to perform in-situ formation of the all-solid-state battery; S7. After the in-situ formation is completed, turn off the power supply, release the high-voltage medium, and remove the cylinder and the all-solid-state battery.

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