A solid-state battery in-situ polymerization solidification process

Abstract

The application belongs to the technical field of electrochemical energy storage batteries, and particularly relates to a solid-state battery in-situ polymerization solidification process. The baked battery roll core without external packaging is placed in an in-situ solidification and formation integrated device; the in-situ polymerization solidification precursor is injected into the device for first pressurization and first heating, so that the precursor is fully infiltrated into the electrode; after the precursor infiltrates the electrode, second pressurization and second heating are performed, so that the precursor is formed into a polymer solid-state electrolyte through in-situ polymerization solidification; after solidification, the battery roll core is charged and formed through an external circuit under the conditions of the second pressurization and the second heating; and the formed roll core is loaded into an external packaging material, so that the solid-state battery is obtained. The application effectively solves the problems of poor in-situ polymerization effect and poor electrode / electrolyte interface contact performance of the solid-state battery using a metal material as a shell due to slow heat conduction and the fact that the rigid shell cannot transmit pressure to the roll core, and the cycle performance and safety of the prepared solid-state battery are greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochemical energy storage batteries, and particularly relates to a solid-state battery in-situ polymerization solidification process. BACKGROUND

[0002] New energy as a national strategic emerging industry has been rapidly developed in recent years. As an important support and auxiliary technology of the new energy industry, electrochemical energy storage devices have become a global research and development hotspot. With the rapid development of portable consumer electronics, mobile communication, new energy electric vehicles and the like, higher requirements are put forward for the energy density, charge-discharge cycle life, capacity retention rate and cycle efficiency of batteries, and various new battery technologies, such as lithium ion batteries, sodium ion batteries, magnesium batteries and lithium-sulfur batteries, have been greatly developed. These batteries are traditionally mainly based on liquid electrolyte, have low flash point, and the polyolefin separators have poor thermal stability, are prone to combustion and explosion in the case of internal short circuit and thermal runaway, and are prone to dendrite generation in the case of large current charge and discharge, and there is a risk of puncturing the separator to cause internal short circuit. Solid-state batteries replace the traditional liquid electrolyte with solid-state electrolyte, and are considered to be the most optimal and most promising technical solution in terms of comprehensive performance.

[0003] In recent years, the in-situ polymerization concept has been proposed, that is, an in-situ solidification precursor formed by mixing a solution of electrolyte salt, small molecule monomer with unsaturated bonds and initiator is injected into the battery, and the organic polymer solid-state electrolyte can be generated by initiating polymerization in the battery. The outer packaging material of the existing battery is an aluminum plastic film, a steel shell or an aluminum shell, and the general process is to place the roll core in the outer packaging material, then inject the in-situ solidification precursor, and then perform in-situ polymerization solidification. However, when a metal outer packaging material such as a steel shell or an aluminum shell is used, since the metal outer packaging material is a rigid shell, it is difficult to directly transmit the pressure to the roll core through the rigid shell after the in-situ solidification precursor is injected into the rigid shell and then subjected to pressure and heat for in-situ polymerization solidification. As a result, effective and stable interface contact cannot be formed between the electrode and the electrolyte, and the interface contact resistance is large. In addition, the temperature cannot be rapidly and uniformly transmitted from the outside to the inside, resulting in that the outer layer of the roll core has formed a solid-state electrolyte, while the inner layer is still a quasi-solid-state or has not been in-situ polymerization solidified, so that the effect of in-situ polymerization solidification cannot be achieved. SUMMARY

[0004] The present application aims to provide a solid-state battery in-situ polymerization solidification process.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] A solid-state battery in-situ polymerization solidification process comprises the following steps:

[0007] (1) placing the roll core of the battery without outer packaging after baking in an in-situ solidification and formation integrated device, and sealing;

[0008] (2) injecting the in-situ polymerization solidified precursor into the in-situ solidification and formation integrated device, and vacuumizing;

[0009] (3) after injecting the precursor, using the device to perform first pressurizing and first heating, so that the precursor is fully infiltrated into the electrode;

[0010] (4) after the precursor infiltrates the electrode, using the device to perform second pressurizing and second heating, so that the precursor is formed into a polymer solid electrolyte through in-situ polymerization solidification;

[0011] (5) after solidification, under the conditions of second pressurizing and second heating, charging the battery roll core through an external circuit;

[0012] (6) packaging the roll core after step (5) into an outer packaging material, thereby obtaining a solid-state battery.

[0013] The thickness of the battery roll core without packaging is 3-15 mm; a thickness less than 3 mm is not conducive to improving the energy density of the battery, and a thickness greater than 15 mm is not conducive to rapid temperature conduction from the outside to the inside, poor in-situ polymerization effect, and easy to cause the degree of polymerization of the solid-state electrolyte to gradually decrease from the outside to the inside along the thickness direction of the roll core, even the outside has been over-polymerized, while the inside has not been completely polymerized, causing uneven ion transmission and heat dissipation, and easily causing thermal runaway safety consequences such as smoking and fire. The injection amount of the in-situ polymerization solidified precursor is 2-5 g / Ah, an injection amount less than 2 g / Ah is insufficient, which reduces the cycle performance of the battery, and an injection amount greater than 5 g / Ah is too much, which reduces the energy density of the battery.

[0014] The first pressurizing pressure in step (4) is 0.3-1 MPa, the first heating temperature is 30-45℃, and the time is 10-30 h;

[0015] The first pressurizing pressure is less than 0.3 MPa, the injected electrolyte has poor infiltration effect due to the lack of capillary action, the pressure is greater than 1 MPa, which easily causes the precursor to be squeezed out from the inside of the battery core; the first heating temperature is less than 30℃, which causes a large temperature difference with the second heating temperature, and when the second heating, the time required for the temperature to be conducted from the outermost side of the roll core to the center is long, which affects the in-situ polymerization and solidification effect, the temperature is greater than 45℃, which easily causes uneven in-situ polymerization and solidification inside and outside, and the precursor cannot be fully infiltrated with the electrode; the time is less than 10 h, and the electrolyte cannot be fully infiltrated with the electrode, and the time is greater than 30 h, which affects the production efficiency.

[0016] The second pressurizing pressure in step (5) is 0.3-2 MPa, the second heating temperature is 50-90℃, and the time is 10-30 h.

[0017] The second pressurization pressure is less than 0.3 MPa, the contact performance between the polymer solid electrolyte and the electrode is poor in the in-situ polymerization solidification process, the battery cycle performance is poor, the pressure is greater than 2 MPa, and the winding core is easily short-circuited; the second heating temperature is less than 50 DEG C, the liquid precursor cannot be in-situ polymerized and solidified, the temperature is greater than 90 DEG C, which exceeds the temperature required for in-situ polymerization reaction, and excessive polymerization is caused, thereby affecting the polymerization effect; the time is less than 10 h, the in-situ polymerization reaction is insufficient, and the time is greater than 30 h, which exceeds the time required for in-situ polymerization reaction and affects the production efficiency.

[0018] The charging formation current ratio is 0.02C-0.2C.

[0019] The charging formation current ratio is less than 0.05C, the charging time is long, the production efficiency is affected, the current ratio is greater than 0.2C, a uniform electrolyte film cannot be formed on the surface of the electrode, and the battery cycle performance is reduced.

[0020] The winding core shape is square or cylindrical.

[0021] The outer packaging material can be one of a steel shell and an aluminum shell.

[0022] A solid-state battery prepared by an in-situ polymerization solidification process, the winding core after formation is taken out, placed in an outer packaging material, sealed, and formed into a solid-state battery.

[0023] An in-situ solidification and formation integrated device of a solid-state battery of the process, comprising a first mold body (1), a second mold body (2), and a third mold body (3), wherein the second mold body (2) is sealingly connected with the first mold body (1), the third mold body (3) is slidingly accommodated in a through hole formed on the second mold body (2) and sealingly abuts against the inner wall of the through hole formed on the second mold body (2); one side of the first mold body (1) away from the second mold body (2) is provided with a heating plate A (101), the other side of the first mold body (1) toward the second mold body (2) is provided with a groove B (104), the groove B (104) contains an insulating plate A (102), and a liquid injection / vacuum extraction port (106) is formed on the groove wall of the groove B (104) and penetrates the first mold body (1); one side of the third mold body (3) toward the first mold body (1) is provided with an insulating plate B (305), the other side of the third mold body (3) away from the first mold body (1) is provided with a heating plate B (301), and a solid-state lithium battery winding core is placed between the insulating plate A (102) and the insulating plate B (305); an electrode assembly (204) is installed on the second mold body (2), and the electrode assembly (204) abuts against the positive electrode tab and the negative electrode tab of the solid-state lithium battery winding core.

[0024] The first mold body (1) is provided with a groove A (103) on the side facing away from the second mold body (2), and the heating plate A (101) is accommodated in the groove A (103); the groove A (103) is separated from the groove B (104) by a partition plate.

[0025] The first mold body (1) is provided with a tab placement area A (107) for placing the positive and negative tab of the solid-state lithium battery roll core on the other side facing the second mold body (2), and the tab placement area A (107) is in communication with the groove B (104).

[0026] The solid-state lithium battery roll core is provided with an insulating pad (108) between the groove wall of the groove B (104) provided with the liquid injection / vacuum port (106), and a gap is left between the solid-state lithium battery roll core and the groove wall of the groove B (104) provided with the liquid injection / vacuum port (106) through the insulating pad (108).

[0027] The second mold body (2) is provided with an annular sealing groove A (201) on the side facing the first mold body (1), and the sealing groove A (201) is located on the periphery of the through hole; the sealing groove A (201) is provided with a sealing ring A (202) for sealing with the first mold body (1).

[0028] The second mold body (2) is provided with a tab placement area B (206) for placing the positive and negative tab of the solid-state lithium battery roll core on the side facing the first mold body (1); the electrode assembly (204) is divided into a positive electrode assembly and a negative electrode assembly; the positive electrode assembly and the negative electrode assembly respectively pass through the second mold body (2) and abut against the positive and negative tabs of the solid-state lithium battery roll core in the tab placement area B (206); the positive electrode assembly comprises a positive electrode core and a positive insulating sleeve sleeved outside the positive electrode core; the negative electrode assembly comprises a negative electrode core and a negative insulating sleeve sleeved outside the negative electrode core.

[0029] The third mold body (3) is provided with an annular sealing groove B (303) on the outer side; the sealing groove B (303) is provided with a sealing ring B (304) for sealing with the inner wall of the through hole provided on the second mold body (2); the third mold body (3) is provided with a protrusion (306) on the side facing the first mold body (1); the insulating plate B (305) abuts against the protrusion (306); the third mold body (3) is provided with a groove C (302) on the other side facing away from the first mold body (1); and the heating plate B (301) is accommodated in the groove C (302).

[0030] The number of roll cores in the solid-state battery is 1-10, and the connection mode between the roll cores can be series connection, parallel connection or series-parallel connection.

[0031] The in-situ polymerization solid-state precursor is not particularly limited, and any polymer solid electrolyte precursor meeting the battery performance can be used, which can be a common polymer solid electrolyte precursor in the art or a deep eutectic precursor.

[0032] The battery core without external packaging can be one of a lithium battery, a sodium battery, a magnesium-sulfur battery, and a lithium-sulfur battery.

[0033] The present application has the advantages and positive effects that:

[0034] The present application is aimed at a solid-state battery with a metal material as a shell, which is formed by placing the battery core of the battery solidified by in-situ polymerization through a specific device of the present application in an external packaging material, and the battery core is first in-situ polymerized and solidified, then is formed into a battery, and is sealed in a shell, effectively solving the problem that the solid-state battery with a metal material as a shell has slow heat conduction, and the rigid shell cannot transmit pressure to the core, resulting in poor in-situ polymerization effect and poor electrode / electrolyte interface contact performance, and the prepared solid-state battery has greatly improved cycle performance and safety.

[0035] The application realizes in-situ polymerization solidification and formation by adopting a specific in-situ solidification and formation integrated device for solid-state battery, which has simple structure and is convenient to disassemble and assemble, can effectively solve the problems that the pressure is difficult to conduct and the temperature cannot be rapidly and uniformly conducted to the battery roll core in the in-situ solidification process of the solid-state battery adopting metal outer packaging material, greatly improves the in-situ polymerization effect; the device is provided with insulating pads on both sides of the liquid injection / vacuum extraction port, so that a vertical distance is left between the bottom of the solid-state lithium battery roll core and the liquid injection / vacuum extraction port, liquid injection is facilitated, and the insulating effect between the solid-state lithium battery roll core and the first mold body is also achieved. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a three-dimensional structure schematic diagram of the device adopted by the embodiment of the application;

[0037] Figure 2 It is a three-dimensional structure schematic diagram of the device adopted by the embodiment of the application;

[0038] Figure 3 It is a three-dimensional structure schematic diagram of the device adopted by the embodiment of the application;

[0039] Figure 4 It is an exploded view of the device adopted by the embodiment of the application;

[0040] Figure 5 It is a structure schematic diagram of the front face of the first mold body in the device adopted by the embodiment of the application;

[0041] Figure 6 It is a structure schematic diagram of the back face of the first mold body in the device adopted by the embodiment of the application;

[0042] Figure 7 It is a local enlarged view of the liquid injection / vacuum extraction port at the bottom of the upper groove B of the first mold body in the device adopted by the embodiment of the application;

[0043] Figure 8 It is a structure schematic diagram of the front face of the second mold body in the device adopted by the embodiment of the application;

[0044] Figure 9 It is a structure schematic diagram of the back face of the second mold body in the device adopted by the embodiment of the application;

[0045] Figure 10 It is an exploded view of the third mold body in the device adopted by the embodiment of the application;

[0046] Figure 11 It is an exploded view of the third mold body in the device adopted by the embodiment of the application;

[0047] Figure 12 It is a disassembled pole piece diagram of the embodiment 3 of the application;

[0048] Figure 13 This is a disassembled electrode diagram of Comparative Example 1 of the present invention.

[0049] Wherein: 1 is the first mold body, 101 is the heating plate A, 102 is the insulating plate A, 103 is the groove A, 104 is the groove B, 105 is the screw, 106 is the liquid injection / vacuum port, 107 is the electrode tab placement area A, and 108 is the insulating pad.

[0050] 2 is the second mold body, 201 is the sealing groove A, 202 is the sealing ring A, 203 is the perforation, 204 is the electrode assembly, 205 is the square hole, and 206 is the tab placement area B.

[0051] 3 is the third mold body, 301 is the heating plate B, 302 is the groove C, 303 is the sealing groove B, 304 is the sealing ring B, 305 is the insulating plate B, and 306 is the protrusion. Detailed Implementation

[0052] The present invention will now be described through specific embodiments. Unless otherwise specified, all technical means used in this invention are methods well known to those skilled in the art. Furthermore, the embodiments should be understood as illustrative, not limiting, of the scope of the invention; the essence and scope of the invention are defined only by the claims. For those skilled in the art, various changes or modifications to the material composition and dosage in these embodiments without departing from the essence and scope of the invention also fall within the protection scope of this invention.

[0053] Example 1

[0054] like Figures 1-4 As shown, the device of the present invention includes a first mold 1, a second mold 2, and a third mold 3. The second mold 2 is sealed to the first mold 1. The third mold 3 is slidably accommodated in a through hole in the second mold 2 and is sealed against the inner wall of the through hole in the second mold 2 to accommodate the volume expansion of the battery during in-situ polymerization and formation after the solid-state lithium battery core is injected with electrolyte. A heating plate A101 is provided on the side of the first mold 1 facing away from the second mold 2, and a groove B104 is provided on the other side of the first mold 1 facing the second mold 2. The first mold 1 has an insulating plate A102 and a liquid injection / vacuum extraction port 106 on the wall of the groove B104. The liquid injection / vacuum extraction port 106 passes through the first mold 1. The third mold 3 has an insulating plate B305 on the side facing the first mold 1 and a heating plate B301 on the other side of the third mold 3 away from the first mold 1. The solid lithium battery core is placed between the insulating plate A102 and the insulating plate B305. The second mold 2 has an electrode assembly 204 installed on it. The electrode assembly 204 abuts against the positive and negative electrode tabs of the solid lithium battery core.

[0055] like Figures 1-7As shown, the first mold body 1 of the embodiment is square, and a recess A103 is formed on the side of the first mold body 1 facing away from the second mold body 2, and the heating plate A101 is accommodated in the recess A103, and the recess A103 is separated from the recess B104 by a partition plate. The recess A103 and the recess B104 of the embodiment are both square grooves, and the heating plate A101 of the embodiment is a square plate.

[0056] As shown, the other side of the first mold body 1 of the embodiment faces the second mold body 2, and the other side of the first mold body 1 is provided with tab placement areas A107 for placing the positive and negative tab of the solid-state lithium battery roll core. The tab placement areas A107 of the embodiment are two, located above the square recess B104, and correspond to the positive and negative tabs respectively. The two tab placement areas 107 are both in communication with the recess B104.

[0057] The liquid injection / vacuum port 106 can be formed on the groove wall at the bottom of the square recess B104, or on the groove walls on the left and right sides. In the embodiment, the liquid injection / vacuum port 106 is formed on the groove wall at the bottom of the square recess B104. An insulating pad 108 is provided between the solid-state lithium battery roll core and the groove wall of the recess B104 where the liquid injection / vacuum port 106 is formed. The insulating pad 108 ensures that there is a vertical distance between the solid-state lithium battery roll core and the groove wall of the recess B104 where the liquid injection / vacuum port 106 is formed, facilitating liquid injection, and also serving as an insulating layer between the solid-state lithium battery roll core and the first mold body 1. The liquid injection / vacuum port 106 is multiple (three in the embodiment), and an insulating pad 108 is provided between adjacent two liquid injection / vacuum ports 106.

[0058] The insulating plate A102 of the embodiment is provided with an extension at the opposite ends of the side facing the groove wall of the recess B104 where the liquid injection / vacuum port 106 is formed. The extension extends from the two ends of the insulating plate A102 to the groove wall of the recess B104 where the liquid injection / vacuum port 106 is formed, and abuts against the groove wall of the recess B104 where the liquid injection / vacuum port 106 is formed. This facilitates liquid injection on the basis of insulation.

[0059] The embodiment is provided with a screw 105 at each corner of the square first mold body 1, and the first mold body 1 is connected to the second mold body 2 by the screw 105.

[0060] As shown in Figures 1-4 and Figures 8-9 As shown, the second mold body 2 of the embodiment is a square plate frame structure, and the through hole formed on the second mold body 2 is a square hole 205.

[0061] The second mold body 2 of the embodiment is provided with tab placement areas B206 for placing positive and negative electrode tabs of the solid-state lithium battery jelly-roll on the side facing the first mold body 1, and the tab placement areas B206 are two and correspond to the positive and negative electrode tabs respectively. An electrode assembly 204 is arranged on the other side of the second mold body 2 away from the first mold body 1, and the electrode assembly 204 is divided into a positive electrode assembly and a negative electrode assembly, and the positive and negative electrode assemblies respectively pass through the second mold body 2 and abut against the positive and negative electrode tabs of the solid-state lithium battery jelly-roll in the tab placement areas B206. The positive electrode assembly includes a positive electrode core and a positive electrode insulating sleeve sleeved outside the positive electrode core, and the negative electrode assembly includes a negative electrode core and a negative electrode insulating sleeve sleeved outside the negative electrode core; the positive electrode assembly is aligned with the tab placement areas A107 and the tab placement areas B206 where the positive electrode tabs are placed respectively, and the negative electrode assembly is aligned with the tab placement areas A107 and the tab placement areas B206 where the negative electrode tabs are placed respectively.

[0062] The second mold body 2 of the embodiment is provided with a ring-shaped sealing groove A201 on the side facing the first mold body 1, and the sealing groove A201 is located at the periphery of the tab placement areas B206 and the square hole 205, and the sealing groove A201 contains a sealing ring A202 for sealing with the first mold body 1.

[0063] The first mold body 1 is provided with a screw rod 105 for connecting with the second mold body 2, and the second mold body 2 is provided with a perforation 203 for the screw rod 105 to pass through; the embodiment is provided with one screw rod 105 at each corner of the square first mold body 1, and each screw rod 105 is located at the periphery of the grooves A101 and B102; the perforations 203 are correspondingly provided at the four corners of the square second mold body 2, and each perforation 203 is located at the periphery of the sealing groove A201; each screw rod 105 is tightened by a nut after passing through the corresponding perforation 203, thereby realizing the connection between the first mold body 1 and the second mold body 2.

[0064] As shown in Figures 1-4 and Figures 10-11 The third mold body 3 of the embodiment is square, and the outer side of the third mold body 3 is provided with a ring-shaped sealing groove B303, and the sealing groove B303 contains a sealing ring B304 for sealing with the inner wall of the square hole 205 provided on the second mold body 2. The third mold body 3 is provided with a protrusion 306 on the side facing the first mold body 1, and the protrusion 306 of the embodiment is square, and an insulating plate B305 abuts against the protrusion 306. The other side of the third mold body 3 away from the first mold body 1 is provided with a groove C302, and a heating plate B301 is contained in the groove C302; during in-situ polymerization, pressure can be applied to the groove C302. The groove C302 of the embodiment is square, and the heating plate B301 of the embodiment is correspondingly a square plate.

[0065] Embodiment 2

[0066] The installation process of the solid-state battery in-situ solidification and formation integrated device is as follows:

[0067] In the first step, the insulating plate A102 is placed at the groove B104 of the first mold body 1, and the square solid-state lithium battery roll core is placed on the insulating plate A102. The positive and negative tabs of the square solid-state lithium battery roll core are respectively fixed on the tab placement area A107 above the groove B104, and the insulating pad 108 is placed at the bottom of the solid-state lithium battery roll core.

[0068] In the second step, the insulating plate B305 is placed at the protrusion 306 of the third mold body 3, and the sealing ring B304 is placed at the sealing groove B303. Then, the front surface of the third mold body 3 (i.e. the surface facing the first mold body 1) is aligned with the groove B104 of the back surface of the first mold body 1 (i.e. the surface facing the second mold body 2), and the whole is covered on the first mold body 1.

[0069] In the third step, the sealing ring A202 is placed at the sealing groove A201 of the second mold body 2, the screw rod 105 provided on the back surface of the first mold body 1 is aligned with the through hole 203 of the second mold body 2, the second mold body 2 is covered on the first mold body 1 through the third mold body 3, and the screw rod 105 is tightened with the nut.

[0070] In the fourth step, the heating plate A101 is placed at the groove A103 on the first mold body 1, and the heating plate B301 is placed at the groove C302 on the third mold body 3.

[0071] In the fifth step, a certain amount of electrolyte is injected through the liquid injection / vacuum extraction port 106, and then vacuum extraction is performed to make the electrolyte fully infiltrate the solid-state lithium battery roll core.

[0072] In the sixth step, the heating plates A101 and B301 are preheated to a set first heating temperature (30-45℃) by an external power supply, and a set first pressurizing pressure (0.3-1 MPa) is applied to the third mold body 3. At the same time, the temperature is raised to a set second heating temperature (50-90℃), and the pressure is raised to a second pressurizing pressure (0.3-2 MPa). The solid-state lithium battery roll core is heated and pressurized to make the liquid electrolyte fully polymerize and solidify in-situ.

[0073] In the seventh step, the electrochemical charging and discharging equipment is connected to the electrode assembly 204 through wires, the charging current is changed, and the solid-state lithium battery roll core is formed.

[0074] In the eighth step, after the formation is completed, the solidified solid-state lithium battery roll core is taken out and placed in a metal outer packaging shell, welded and sealed to form a solid-state lithium battery product.

[0075] Example 3

[0076] Using the above device, the square battery roll core after baking in a conventional manner was taken, the positive active material was LiNi 0.8 Co 0.1 Mn 0.1 O2, the negative active material was silicon-carbon composite material, the core thickness was 7 mm, and the design capacity was 20 Ah; the core was placed on the insulation plate A102 of the in-situ solidification and formation integrated device in Example 1, and was sealed; a liquid mixture formed by methyl methacrylate (2-(((2-oxo-1,3-dioxolan-4-yl) methoxy) formamido) ethyl ester, butanedinitrile, lithium bistrifluoromethanesulfonylimide, lithium difluoro(oxalato)borate and azobis isobutyronitrile in a mass ratio of 3:10:7:0.3:0.5 was injected into the core through the injection port 106, the injection amount was 3.1 g / Ah, and after the injection was completed, the device was vacuumized; after the vacuumization was completed, the device was subjected to first pressurization and first heating by the screw pressurization mechanism and the heating mechanism, the first pressurization pressure was 0.5 MPa, the first heating temperature was 35 DEG C, and the time was 24 h, so that the precursor was fully infiltrated into the electrode; then the device was subjected to second pressurization and second heating, the second pressurization pressure was 1.5 MPa, the second heating temperature was 60 DEG C, and the time was 6 h, so that the precursor was in-situ polymerized and solidified to form a polymer solid electrolyte; on this basis, the second pressurization pressure and the second heating temperature were kept unchanged, the electrode port of the device was externally connected to a charging and formation device, and the battery was charged and formed, and the formation current rate was 0.1 C; after the formation was completed, the core was taken out of the device, was placed in an aluminum shell outer packaging material, was sealed, and a solid-state lithium battery was formed.

[0077] Test results: the energy density of the above battery was 245.6 Wh / kg, the capacity retention rate was 93.53% after 1000 times of continuous charge-discharge at a 0.5 C rate current, and the average charge-discharge efficiency was 99.65%; as shown in Figure 12 , it was found that the precursor was completely in-situ polymerized and solidified to form a polymer solid electrolyte after the battery was disassembled.

[0078] Comparative Example 1

[0079] The roll core after drying in Example 1 was directly placed into an aluminum shell outer packaging material, the in-situ polymerization and solidification precursor was injected, vacuumization was performed, and when the first pressurization was 0.5 MPa, it was found that the aluminum shell was hard in texture, and could not effectively transmit the pressure to the core; the second pressurization was also invalid, and the second heating heat could not be quickly transmitted to the inside of the core; at this time, it was found that the solid electrolyte had been solidified along the outside of the core thickness direction, and there was still some liquid in-situ polymerization and solidification precursor left in the inside of the core after the battery was disassembled, as shown in Figure 13As shown, no polymer solid-state electrolyte is converted, no real solid-state lithium battery is formed.

[0080] Tested: the energy density of the above battery is 245.6 Wh / kg, the capacity retention rate of the above battery is 86.82% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulombic efficiency is 96.35%, and in terms of safety, the needle test shows that the battery smokes, ignites, but does not explode.

[0081] Comparative Example 2

[0082] The thickness of the winding core of Example 1 is changed to 2 mm, and the rest is the same as Example 1.

[0083] Tested: the energy density of the above battery is 210.3 Wh / kg, the capacity retention rate is 92.56% after 1000 times of continuous charge and discharge at 0.5C rate, the average charge and discharge efficiency is 98.36%, and in terms of safety, the needle test shows that the battery does not smoke, does not ignite, and does not explode, and it can be seen that when the winding core thickness does not reach the corresponding thickness, the energy density decreases, and the capacity retention rate and the average charge and discharge efficiency decrease.

[0084] Comparative Example 3

[0085] The thickness of the winding core of Example 1 is changed to 18 mm, and the rest is the same as Example 1.

[0086] Tested: the energy density of the above battery is 248.6 Wh / kg, the capacity retention rate is 78.24% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulombic efficiency is 96.35%, and in terms of safety, the needle test shows that the battery smokes, but does not ignite and does not explode.

[0087] Comparative Example 4

[0088] The in-situ polymerization solidified precursor in Example 1 is changed to 1.5 g / Ah, and the rest is the same as Example 1.

[0089] Tested: the energy density of the above battery is 205.3 Wh / kg, the capacity retention rate is 64.25% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulombic efficiency is 92.36%, and in terms of safety, the needle test shows that the battery does not smoke, does not ignite, and does not explode.

[0090] Comparative Example 5

[0091] The in-situ polymerization solidified precursor in Example 1 is changed to 5.5 g / Ah, and the rest is the same as Example 1.

[0092] Test: The energy density of the above battery is 198.7 Wh / kg, the capacity retention rate is 90.61% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulomb efficiency is 97.14%, and in terms of safety, the needle test shows that the battery smokes, but does not catch fire or explode. It can be seen that when the amount of in-situ polymerization solidification precursor added is too much, the energy density of the battery decreases, the safety becomes poor, and the capacity retention rate and the average coulomb efficiency decrease.

[0093] Comparative Example 6

[0094] In Example 1, the second pressurizing pressure is changed to 0.2 MPa, and the rest is the same as Example 1.

[0095] Test: The energy density of the above battery is 244.5 Wh / kg, the capacity retention rate is 86.48% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulomb efficiency is 96.11%, and in terms of safety, the needle test shows that the battery does not smoke, catch fire or explode.

[0096] Comparative Example 7

[0097] In Example 1, the second pressurizing pressure is changed to 5 MPa, and the rest is the same as Example 1. Test: The winding core is short-circuited.

[0098] Comparative Example 8

[0099] In Example 1, the second heating temperature is changed to 40℃, and the rest is the same as Example 1. After disassembling the battery, it is found that the liquid in-situ polymerization solidification precursor does not in-situ polymerize and solidify.

[0100] Test: The energy density of the above battery is 243.1 Wh / kg, the capacity retention rate is 79.82% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulomb efficiency is 96.39%, and in terms of safety, the needle test shows that the battery smokes and catches fire, but does not explode.

[0101] Comparative Example 9

[0102] In Example 1, the second heating temperature is changed to 100℃, and the rest is the same as Example 1. After disassembling the battery, it is found that the liquid in-situ polymerization solidification precursor is over-polymerized and solidified due to the high temperature, and the electrolyte is brittle.

[0103] Test: The energy density of the above battery is 210.2 Wh / kg, the capacity retention rate is 72.25% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulomb efficiency is 94.38%, and in terms of safety, the needle test shows that the battery smokes, but does not catch fire or explode.

[0104] Comparative Example 10

[0105] The second pressurization and the second heating time in Example 1 is changed to 8h, and the rest is the same as Example 1. After the battery is disassembled, it is found that some liquid in-situ polymerization solidification precursor has not been polymerized and solidified.

[0106] Test: The energy density of the above battery is 245.6Wh / kg, the capacity retention rate of the above battery is 83.62% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulomb efficiency is 97.66%, and in terms of safety, the needle test shows that the battery smokes and ignites, but does not explode.

[0107] Comparative Example 11

[0108] The charge formation current rate in Example 1 is changed to 0.5C, and the rest is the same as Example 1.

[0109] Test: The energy density of the above battery is 245.1Wh / kg, the capacity retention rate of the above battery is 78.46% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulomb efficiency is 95.05%, and in terms of safety, the needle test shows that the battery smokes and ignites, but does not explode.

[0110] Example 4

[0111] According to the device design of Example 1, the three same winding cores after formation in Example 3 are placed in the aluminum shell outer packaging material, and the connection mode of the three winding cores is parallel.

[0112] Test: The energy density of the battery is 249.3Wh / kg, the capacity retention rate of the above battery is 93.26% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulomb efficiency is 99.56%, and in terms of safety, the needle test shows that the battery does not smoke, does not ignite, and does not explode.

[0113] Example 5

[0114] The device of Example 1 is used, and the winding core and the winding core after in-situ polymerization solidification condition formation in Example 3 are placed in the steel shell outer packaging material.

[0115] Test: The energy density of the battery is 230.6Wh / kg, the capacity retention rate of the above battery is 93.51% after 1000 times of continuous charge and discharge at 0.5C rate, the average coulomb efficiency is 99.63%, and in terms of safety, the needle test shows that the battery does not smoke, does not ignite, and does not explode.

[0116] Example 6

[0117] Take the square battery roll core after roasting, the positive active material is lithium manganate, the negative active material is graphite material, the roll core thickness is 8 mm, and the design capacity is 14 Ah; the battery core is placed on the insulation plate A102 of the in-situ solidification and formation integrated device, sealed; liquid in-situ polymerization solidification precursor (a liquid mixture formed by vinylene carbonate, ethylene carbonate, diethyl carbonate, lithium difluoroboric acid oxalate and azobis isobutyronitrile in a mass ratio of 10:33:32:24:1) is injected into the liquid injection port 106, the injection amount is 2.8 g / Ah, and after the injection is completed, the device is vacuumized; after vacuumizing, the above-mentioned device is first pressurized and first heated by the screw pressurizing mechanism and the heating mechanism, the first pressurization pressure is 0.75 MPa, the first heating temperature is 40°C, and the time is 20 h, so that the liquid in-situ polymerization solidification precursor is fully infiltrated into the electrode; then the above-mentioned device is second pressurized and second heated, the second pressurization pressure is 1.2 MPa, the second heating temperature is 65°C, and the time is 22 h, so that the liquid in-situ polymerization solidification precursor is in-situ polymerized and solidified to form a polymer solid electrolyte; on this basis, the second pressurization pressure and the second heating temperature are kept unchanged, the electrode port on the device is externally connected to the charging and forming equipment, the battery is charged and formed, and the formation current rate is 0.1C; after the formation is completed, the roll core is taken out from the device and sealed in the aluminum shell outer packaging material to form a solid-state lithium battery.

[0118] Test: The energy density of the above-mentioned battery is 175.6 Wh / kg, the capacity retention rate is 92.52% after 1000 times of continuous charge-discharge at 0.5C rate current, the average charge-discharge efficiency is 99.61%, and in terms of safety, the needle test shows that the battery does not smoke, does not catch fire, and does not explode.

[0119] Example 7

[0120] A baked square battery core is taken, with lithium iron phosphate as the positive electrode active material and graphite as the negative electrode active material. The core thickness is 8mm, and the designed capacity is 12Ah. The battery core is placed on the insulating plate A102 in the in-situ solidification and formation integrated device and sealed. A liquid in-situ polymerization solidification precursor (a liquid mixture of vinylene carbonate, lithium difluorooxalate borate, and azobisisobutyronitrile in a mass ratio of 10:89:1) is injected into the core through the injection port 106. The electrolyte volume is 3.5g / Ah. After injection, the device is evacuated. After evacuation, the device is pressurized and heated for the first time using a screw pressurization mechanism and a heating mechanism. The first pressurization pressure is 0.5... The device applies pressure at 1.5 MPa and heats at 30°C for 24 hours to fully impregnate the liquid-state in-situ polymerized solid-state precursor into the electrode. Then, it applies a second pressure and heat at 70°C for 16 hours to solidify the liquid-state polymerized solid-state precursor into a polymer solid electrolyte. Maintaining the second pressure and heating temperature, an external charging and formation device is connected through the electrode port to charge and form the battery at a formation current rate of 0.1C. After formation, the core is removed from the device, placed in an aluminum shell packaging material, and sealed to form a solid-state lithium battery.

[0121] Tests showed that the battery has an energy density of 160.6Wh / kg, a capacity retention rate of 95.82% after 1000 continuous charge-discharge cycles at a 0.5C rate, and an average charge-discharge efficiency of 99.68%. In terms of safety, the needle penetration test showed that the battery did not smoke, catch fire, or explode.

[0122] Example 8

[0123] Take the baked square battery core, the positive electrode active material is sulfur-carbon composite material, the negative electrode active material is lithium metal, the core thickness is 8mm, and the designed capacity is 30Ah; place the battery core on the insulating plate A102 in the in-situ solidification and formation integrated device and seal it; inject the in-situ polymerization solidification precursor (a liquid mixture formed by polyethylene glycol methyl ether acrylate, lithium difluorooxalate borate, and azobisisobutyronitrile in a mass ratio of 8:91:1) into it through the liquid injection port 106, the injection amount is 4g / Ah, after injection, the device is evacuated; after evacuation, the above device is subjected to the first pressurization and the first heating through the screw pressurization mechanism and the heating mechanism. The device applies a pressure of 0.5 MPa and a first heating temperature of 35°C for 24 hours to fully wet the precursor into the electrode. Then, it applies a second pressure and a second heating temperature of 1.2 MPa and 70°C for 20 hours to allow the precursor to polymerize and solidify in situ, forming a polymer solid electrolyte. Maintaining the second pressure and heating temperature, an external charging and formation device is connected through the electrode port of the device to charge and form the battery at a formation current rate of 0.1C. After formation, the core is removed from the device, placed in an aluminum shell packaging material, and sealed to form a solid lithium-sulfur battery.

[0124] Tests showed that the battery has an energy density of 520Wh / kg, a capacity retention rate of 88.3% after 300 continuous charge-discharge cycles at a 0.5C rate, and an average charge-discharge efficiency of 98.35%. In terms of safety, the needle penetration test showed that the battery did not smoke, catch fire, or explode.

[0125] Example 9

[0126] Take the baked square battery core. The positive electrode active material is a sulfur-carbon composite material, and the negative electrode active material is metallic magnesium. The core thickness is 8mm, and the designed capacity is 25Ah. Place the battery core on the insulating plate A102 in the in-situ solidification and formation integrated device and seal it. Inject the in-situ polymerization solidification precursor (a liquid mixture formed by polyethylene glycol methyl ether acrylate, magnesium difluorooxalate borate, and azobisisobutyronitrile in a mass ratio of 7:92:1) into the device through the injection port 106 at a rate of 3.8g / Ah. After injection, evacuate the device. After evacuation, apply the first pressurization and first heating to the device using a screw pressurization mechanism and a heating mechanism. The device applies a pressure of 0.5 MPa and a heating temperature of 35°C for 24 hours to fully impregnate the precursor into the electrode. Then, it applies a second pressure of 1.1 MPa and a heating temperature of 80°C for 20 hours to solidify the precursor in situ, forming a polymer solid electrolyte. Maintaining the second pressure and heating temperature, an external charging and formation device is connected through the electrode port to charge and form the battery at a current rate of 0.1C. After formation, the core is removed from the device, placed in an aluminum shell packaging material, and sealed to form a solid magnesium-sulfur battery.

[0127] Tests showed that the battery has an energy density of 502.6 Wh / kg, a capacity retention rate of 85.4% after 300 continuous charge-discharge cycles at a 0.5C rate, and an average charge-discharge efficiency of 98.12%. In terms of safety, the needle penetration test showed that the battery did not smoke, catch fire, or explode.

[0128] Example 10

[0129] A baked square battery core is taken, with Na3V2(PO4)3 as the positive electrode active material and hard carbon as the negative electrode active material. The core thickness is 7.5 mm, and the designed capacity is 11 Ah. The battery core is placed on the insulating plate A102 in the in-situ solidification and formation integrated device and sealed. An in-situ polymerized solidification precursor is injected into the device through the injection port 106 at a rate of 3.8 g / Ah. After injection, the device is evacuated. After evacuation, the device is subjected to a first pressurization and a first heating through a screw pressurization mechanism and a heating mechanism. The first pressurization pressure is 0.5 MPa, and the first heating temperature is... The temperature was set at 35°C for 24 hours to allow the precursor to fully wet the electrodes. Then, the device underwent a second pressurization and heating process, with a second pressurization pressure of 1.3 MPa and a second heating temperature of 65°C for 20 hours, to allow the precursor to polymerize and solidify in situ, forming a polymer solid electrolyte. Maintaining the second pressurization pressure and heating temperature constant, an external charging and formation device was connected through the electrode ports of the device to charge and form the battery at a formation current rate of 0.1C. After formation, the core was removed from the device, placed in an aluminum shell packaging material, and sealed to form a solid sodium battery.

[0130] Tests showed that the energy density of the battery was 158.9 Wh / kg, the capacity retention rate was 93.6% after 1000 continuous charge-discharge cycles at a 0.5C rate, and the average charge-discharge efficiency was 99.35%. In terms of safety, the needle penetration test showed that the battery did not smoke, catch fire, or explode.

[0131] Example 11

[0132] The square battery core in Example 1 was changed to a cylindrical shape, and the rest was the same as in Example 1.

[0133] Tests showed that the battery has an energy density of 295.6 Wh / kg, a capacity retention rate of 94.56% after 1000 continuous charge-discharge cycles at a 0.5C rate, and an average charge-discharge efficiency of 99.73%. In terms of safety, the needle penetration test showed that the battery did not smoke, catch fire, or explode.

[0134] The embodiments described above represent only a few implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A solid-state battery in-situ polymerization solidification process, characterized in that: (1) Place the baked battery core without outer packaging into an in-situ solidification and formation integrated device and seal it; (2) Inject the in-situ polymer solidification precursor into the in-situ solidification and formation integrated device and evacuate it; (3) After injecting the precursor, use the device to apply the first pressure and the first heat to fully wet the precursor into the electrode; (4) After the precursor wets the electrode, use the device to apply the second pressure and the second heat to form a polymer solid electrolyte through in-situ polymer solidification; (5) After solidification, under the conditions of the second pressure and the second heat, charge the battery core through an external circuit to form it; (6) Put the core formed in step (5) into the outer packaging material to obtain a solid battery.

2. The process according to claim 1, characterized in that: The thickness of the unpackaged battery core is 3-15mm; the injection amount of the in-situ polymerized solid-state precursor is 2-5g / Ah.

3. The process according to claim 1, characterized in that: The first pressurization pressure in step (4) is 0.3-1 MPa, the first heating temperature is 30-45℃, and the time is 10-30 h; the second pressurization pressure in step (5) is 0.3-2 MPa, the second heating temperature is 50-90℃, and the time is 10-30 h.

4. The process according to claim 1, characterized in that: The charging current multiplier is 0.02C to 0.2C.

5. A solid-state battery prepared by the in-situ polymerization solidification process according to claim 1, characterized in that: The formed core as described in claim 1 is removed, placed in outer packaging material, and sealed to form a solid-state battery.

6. An integrated apparatus for in-situ solid-state formation and solidification of solid-state batteries according to the process described in claim 1, characterized in that: The system includes a first mold (1), a second mold (2), and a third mold (3). The second mold (2) is sealed to the first mold (1). The third mold (3) is slidably housed in a through hole on the second mold (2) and is sealed against the inner wall of the through hole on the second mold (2). The first mold (1) has a heating plate A (101) on the side facing away from the second mold (2). The first mold (1) has a groove B (104) on the other side facing the second mold (2). An insulating plate A (102) is placed in the groove B (104). A liquid injection / vacuum port (106) is provided on the groove wall of the groove B (104). The liquid injection / vacuum port (106) penetrates through the first mold (1). The third mold (3) has an insulating plate B (305) on the side facing the first mold (1). A heating plate B (301) is provided on the other side of the mold (3) facing away from the first mold (1), and the solid lithium battery core is placed between the insulating plate A (102) and the insulating plate B (305); an electrode assembly (204) is installed on the second mold (2), and the electrode assembly (204) abuts against the positive electrode tab and the negative electrode tab of the solid lithium battery core; a groove A (103) is opened on the side of the first mold (1) facing away from the second mold (2), and the heating plate A (101) is housed in the groove A (103), and the groove A (103) and the groove B (104) are separated by a partition; an electrode tab placement area A (107) for placing the positive electrode tab and the negative electrode tab of the solid lithium battery core is opened on the other side of the first mold (1) facing the second mold (2), and the electrode tab placement area A (107) is connected to the groove B (104).

7. The apparatus according to claim 6, characterized in that: An insulating pad (108) is provided between the solid lithium battery core and the groove wall of the groove B (104) with the liquid injection / vacuum port (106), and a gap is left between the solid lithium battery core and the groove wall of the groove B (104) with the liquid injection / vacuum port (106) through the insulating pad (108).

8. The apparatus according to claim 6, characterized in that: The second mold (2) has an annular sealing groove A (201) on the side facing the first mold (1). The sealing groove A (201) is located around the through hole. The sealing groove A (201) contains a sealing ring A (202) for sealing with the first mold (1). The second mold (2) has an electrode tab placement area B (206) on the side facing the first mold (1) for placing the positive electrode tab and the negative electrode tab of the solid lithium battery core. The electrode assembly (204) is divided into a positive electrode assembly and a negative electrode assembly. The positive electrode assembly and the negative electrode assembly pass through the second mold (2) respectively and abut against the positive electrode tab and the negative electrode tab of the solid lithium battery core in the electrode tab placement area B (206). The positive electrode assembly includes a positive electrode core and a positive electrode insulating sleeve sleeved outside the positive electrode core. The negative electrode assembly includes a negative electrode core and a negative electrode insulating sleeve sleeved outside the negative electrode core.

9. The apparatus according to claim 6, characterized in that: The outer side of the third mold (3) is provided with an annular sealing groove B (303), and the sealing groove B (303) contains a sealing ring B (304) for sealing with the inner wall of the through hole opened on the second mold (2); the third mold (3) has a protrusion (306) on the side facing the first mold (1), and the insulating plate B (305) abuts against the protrusion (306); the other side of the third mold (3) facing away from the first mold (1) is provided with a groove C (302), and the heating plate B (301) is accommodated in the groove C (302).

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