A structurally stable all-solid-state lithium ion battery and a preparation method thereof

Abstract

The application discloses a full-solid-state lithium ion battery with stable structure and a preparation method thereof. The lithium-rich manganese-based full-solid-state lithium ion battery comprises a double-coated layered lithium-rich manganese positive electrode, a solid electrolyte layer and a negative electrode. The lithium-rich manganese active material is (1-z)LiNi 0.33 Co 0.33+x Mn 0.33‑x O2‑zLi2MnO3‑yLiNiO 2， x=0‑0.33, y=0‑0.8, and 0 The conductivity and structure of the lithium-rich manganese are optimized by adjusting the content of the Co and LiNiO2 components in the lithium-rich manganese, the prepared lithium-rich manganese-based full-solid-state lithium ion battery has excellent cycle stability, the conductivity is increased by two orders of magnitude when the content of Co is increased by 0.10, the LiNiO2 spinel structure is formed on the surface of the lithium-rich manganese, the ion diffusion on the surface of the lithium-rich manganese material is further improved, the discharge capacity of the 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2‑0.5Li2MnO3‑0.1LiNiO2 positive electrode can reach 215 mAh g ‑1 , and the capacity retention rate is as high as 83% after 1000 cycles in the full-solid-state battery, which is far superior to the cycle performance of the liquid-state battery. The preparation method disclosed by the application is simple and efficient, and is expected to realize the full-solid-state commercial application of the high-capacity lithium-rich manganese material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of secondary batteries, and more particularly to a full-solid-state lithium ion battery with stable structure and a preparation method thereof. BACKGROUND

[0002] Full-solid-state lithium ion batteries using incombustible inorganic solid electrolytes have been widely studied in recent years due to their excellent safety. However, the current international research is still mainly focused on lithium cobalt oxide (LCO) and high-nickel cathodes (NCM), because LCO and NCM themselves have good electronic and ionic conductivity (10 -5 -10 -3 S·cm -1 ) and can achieve good performance in full-solid-state batteries without adding carbon conductive agents. However, due to the limitations of LCO and NCM cathode materials, the actual capacity of the cathode side is all below 200 mAh·g -1 The energy density is generally also limited to within 760 Wh·kg -1 , which is far from meeting people's demand for high-energy-density batteries. From this perspective, if a lithium-rich manganese oxide cathode material with an actual capacity of up to 280 mAh·g -1 and an energy density of up to 1000 Wh·kg -1 is applied in a full-solid-state lithium ion battery, it will be able to meet people's demand for high energy density and high safety at the same time. In addition, the transition metal dissolution problem of lithium-rich manganese cathodes in liquid batteries is an important reason for the capacity attenuation, and full-solid-state batteries have been proven to be able to inhibit the dissolution of transition metals. Therefore, the application of lithium-rich manganese cathode materials in full-solid-state batteries may achieve better cycle performance.

[0003] The existing full-solid-state lithium ion battery includes a cathode, a solid electrolyte layer, and an anode, the solid electrolyte layer is a sulfide electrolyte material, and the active material in the anode is elemental lithium material, lithium-carbon composite material, lithium-indium alloy material, or lithium-silicon-carbon composite material.

[0004] The lithium-rich manganese cathode is currently applied in liquid batteries. However, so far, there is no report on the application of lithium-rich manganese cathodes in full-solid-state batteries internationally. This may be related to the low electronic conductivity (10 -9 -10 -8 S·cm -1 ), low ionic conductivity (10 -11 S·cm -1 ), and high working voltage (4.8 V) of the lithium-rich manganese cathode material. Because low conductivity is not conducive to the utilization of active materials, and high working voltage will accelerate the decomposition of solid electrolytes. SUMMARY

[0005] To solve the above problems, the application provides a structure-stable all-solid-state lithium ion battery and a preparation method thereof.

[0006] To achieve the object of the application, the technical scheme provided by the application is as follows:

[0007] A preparation method of a structure-stable all-solid-state lithium ion battery, wherein the preparation method of the positive electrode is as follows:

[0008] First, a lithium-rich manganese positive electrode material is prepared: after the lithium-rich manganese active material and the stable coating layer raw material are blended and dried, the stable coating layer originally dissolved in the solvent is coated on the surface of the layered lithium-rich manganese positive electrode material with the volatilization of the solvent; then the layered lithium-rich manganese positive electrode material coated with the stable coating layer is mixed with a sulfide solid electrolyte solution and dried again to form a double-coated lithium-rich manganese positive electrode material; the content of the stable coating layer raw material and the sulfide solid electrolyte is 1-3% of the mass of the lithium-rich manganese active material;

[0009] Then, the double-coated lithium-rich manganese positive electrode material, the sulfide electrolyte and the conductive agent are ground and mixed for 0.5-1 hours, and after uniform mixing, the powder is cold-pressed through a mold to prepare a positive electrode for an all-solid-state lithium ion battery; the pressure is 50-150 MPa, and the time is 1-5 min; the mass fraction ratio of the lithium-rich manganese positive electrode material, the sulfide solid electrolyte and the conductive agent is 50-95: 10-40: 1-10.

[0010] The above battery assembly process is as follows: first, 100 mg of Li6PS5Cl solid electrolyte powder is added to a tablet pressing mold, and the powder electrolyte is pressed into a round tablet under a pressure of 100-120 MPa for 1-2 min; then the positive electrode is arranged on one side of the electrolyte round tablet under a pressure of 500-600 MPa for 2-4 min; finally, a 100 μm thick indium sheet and a 50 μm thick lithium sheet are respectively arranged on the other side of the electrolyte round tablet.

[0011] The above lithium-rich manganese active material (1-z)LiNi 0.33 Co 0.33+x Mn 0.33-x O2-zLi2MnO3-yLiNiO 2， x = 0-0.33, y = 0-0.8, 0

[0012] The above lithium-rich manganese active material is selected from

[0013] 0.5LiNi 0.33 Co 0.43 Mn 0.23O2-0.5Li2MnO3-0.05LiNiO2 or 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.1LiNiO2.

[0014] The stable coating layer is selected from LiNbO3, and the sulfide solid electrolyte coating layer is selected from Li6PS5Cl sulfide electrolyte.

[0015] The mass ratio of the lithium-rich manganese positive electrode material, the sulfide solid electrolyte and the conductive agent is preferably 55-65:30-40:3-7.

[0016] Most preferably, the mass ratio of the lithium-rich manganese positive electrode material, the sulfide solid electrolyte and the conductive agent is 60:35:5.

[0017] The thickness of the stable coating layer on the surface of the layered lithium-rich manganese active material and the thickness of the sulfide solid electrolyte coating layer are respectively 1-50 nm.

[0018] Further preferably, the thicknesses are respectively 2-20 nm.

[0019] The lithium-rich manganese-based full solid-state lithium ion battery prepared by the preparation method.

[0020] The lithium-rich manganese oxide positive electrode material is applied in the sulfide full solid-state lithium ion battery, the content of Co and LiNiO2 components in the lithium-rich manganese is regulated, the electrical conductivity and the structure of the lithium-rich manganese are optimized, so that the lithium-rich manganese full solid-state battery has good cycle performance. Through detailed electrochemical analysis and structural characterization, the mechanism of the excellent cycle performance of the lithium-rich manganese positive electrode in the sulfide full solid-state battery is systematically studied, and the present application has the following beneficial effects compared with the prior art.

[0021] (1) The lithium-rich manganese positive electrode material of the present application greatly improves the electronic and ionic conductivities of the material through element composition regulation, suitable surface double-coating double-regulation and interaction. The electronic and ionic conductivities of the lithium-rich manganese positive electrode material itself have a great influence on the performance of the full solid-state battery. Increasing the cobalt content in the lithium-rich manganese material can significantly improve the electronic and ionic conductivities of the lithium-rich manganese material, but too much cobalt content is not conducive to the capacity and structural stability of the lithium-rich manganese material. Increasing the content of Co by 0.10 can make the electrical conductivity increase by two orders of magnitude, and the 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3 positive electrode also has a high capacity of 213.4 mAh g -1 .

[0022] (2) The 0.5LiNi0.33 Co 0.43 Mn 0.23 The O2-0.5Li2MnO3 lithium-rich manganese cathode, combined with LiNiO2 components, not only improves electronic and ionic conductivity but also forms a spinel structure in situ on the surface of the lithium-rich manganese, further enhancing ion diffusion on the surface of the lithium-rich manganese material. Among these components, 0.5LiNi... 0.33 Co 0.43 Mn 0.23 O 2- -0.5Li2MnO3-0.05LiNiO2 and 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.1LiNiO2.

[0023] The electronic conductivity of the positive electrode is 1.82 × 10⁻⁶. -5 S cm -1 and 7.36×10 -5 S cm -1 Compared to the original 0.5LiNi 0.33 Co 0.33 Mn 0.33 O 2- The conductivity of the -0.5Li2MnO3 cathode is increased by four orders of magnitude, and is now comparable to that of the ternary cathode.

[0024] (3) The lithium-rich manganese cathode prepared by the process of this invention exhibits excellent electrochemical performance in all-solid-state batteries. Among them, 0.5LiNi 0.33 Co 0.43 Mn 0.23 O 2- The highest capacity of -0.5Li2MnO3-0.05LiNiO2 can reach 244.5 mAh·g. -1 With an energy density as high as 853 Wh·kg -1 After 700 cycles in an all-solid-state battery, the capacity retention rate was 62%, which is superior to the cycle performance of liquid batteries (46%); 0.5LiNi 0.33 Co 0.43 Mn 0.23 The discharge capacity of the O2-0.5Li2MnO3-0.1LiNiO2 cathode can reach 215 mAh·g. -1 After 1,000 cycles in an all-solid-state battery, the capacity retention rate is as high as 83%, which is far superior to the cycle performance of liquid batteries (36%).

[0025] (4) Mechanism analysis shows that compared with liquid batteries, the full solid-state battery prepared by the preparation process of the application can inhibit the problems of transition metal dissolution, oxygen release and transformation from layered to spinel phase of the lithium-rich manganese positive electrode material, so that the lithium-rich manganese positive electrode has better cycle stability in the sulfide full solid-state battery.

[0026] (5) Unlike lithium cobaltate and ternary positive electrode sulfide full solid-state batteries, the oxidation decomposition of Li6PS5Cl electrolyte within the working voltage (2.0-4.8 V) of lithium-rich manganese is reversible, and the-S 0 produced by oxidation can be completely reduced, and the oxidized P2S7 4- ion can also conduct lithium ions, so that the composite positive electrode in the lithium-rich manganese full solid-state battery can maintain good ion transmission during long cycle, thereby ensuring the stability of the lithium-rich manganese full solid-state battery during long cycle. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 EIS spectrum of the ion-blocking battery of the positive electrode material prepared for Example 1;

[0028] Figure 2 Direct current polarization result of the electron-blocking battery of the positive electrode material prepared for Example 1;

[0029] Figure 3 EIS spectrum of the ion-blocking battery of the positive electrode material prepared for Example 2;

[0030] Figure 4 Direct current polarization result of the electron-blocking battery of the positive electrode material prepared for Example 2;

[0031] Figure 5 EIS spectrum of the ion-blocking battery of the positive electrode material prepared for Example 3;

[0032] Figure 6 Direct current polarization result of the electron-blocking battery of the positive electrode material prepared for Example 3;

[0033] Figure 7 EIS spectrum of the ion-blocking battery of the positive electrode material prepared for Example 4;

[0034] Figure 8 Direct current polarization result of the electron-blocking battery of the positive electrode material prepared for Example 4;

[0035] Figure 9 EIS spectrum of the ion-blocking battery of the positive electrode material prepared for Example 5;

[0036] Figure 10 Direct current polarization result of the electron-blocking battery of the positive electrode material prepared for Example 5;

[0037] Figure 11 EIS spectra of ion-blocking cells for the cathode material prepared in Example 6;

[0038] Figure 12 DC polarization results of electron-blocking cells for the cathode material prepared in Example 6;

[0039] Figure 13 EIS spectra of ion-blocking cells for the cathode material prepared in Example 7;

[0040] Figure 14 DC polarization results of electron-blocking cells for the cathode material prepared in Example 7;

[0041] Figure 15 EIS spectra of ion-blocking cells for the cathode material prepared in Example 8;

[0042] Figure 16 DC polarization results of electron-blocking cells for the cathode material prepared in Example 8;

[0043] Figure 17 Cycle performance of the full solid-state lithium ion battery prepared in Example 8 at 0.5C;

[0044] Figure 18 EIS spectra of ion-blocking cells for the cathode material prepared in Example 9;

[0045] Figure 19 DC polarization results of electron-blocking cells for the cathode material prepared in Example 9;

[0046] Figure 20 Cycle performance of the full solid-state lithium ion battery prepared in Example 9 at 0.5C;

[0047] Figure 21 EIS spectra of ion-blocking cells for the cathode material prepared in Example 10;

[0048] Figure 22 DC polarization results of electron-blocking cells for the cathode material prepared in Example 10;

[0049] Figure 23 EIS spectra of ion-blocking cells for the cathode material prepared in Example 11;

[0050] Figure 24 DC polarization results of electron-blocking cells for the cathode material prepared in Example 11. DETAILED DESCRIPTION

[0051] The application will be further described with reference to the following examples. These examples are intended to be illustrative only and are not intended to limit the scope of the application.

[0052] The present application provides a kind of lithium-rich manganese-based full solid-state lithium ion battery, and the raw materials used in its preparation process are described as follows:

[0053] The type of the conductive agent is not particularly required, and can be selected from commonly used types in the art, such as one or more of graphite, acetylene black, Super P, carbon nanotube, graphene, and Ketjen black.

[0054] The solvent is selected from ethanol or a mixture of ethanol and other organic solvents; the selection is adaptive according to the type of the stable coating layer used; the organic solvent is selected from one or more of N-methyl pyrrolidone and p-xylene; preferably, it is selected from ethanol.

[0055] The mixing is performed by using common mixing methods in the art, such as ball milling, mechanical stirring, or magnetic stirring, etc.

[0056] After drying, common vacuum drying and heating drying in the art are used.

[0057] The stable coating layer raw material is selected from one or more of simple oxides TiO2, Al2O3, ZrO2, MnO2, MoO3, CeO2, etc., phosphates FePO4, CoPO4, NiPO4, etc., fluorides GaF2, AlF3, SmF3, etc., oxides and lithium salts LiAlO2, LiZrO3, LiTiO3, Li4Ti5O12, Li3VO4, LiNiPO4, LiNbO3, etc., good electronic conductor elements Al, carbon materials, etc., and organic polymers polyaniline (PAN) and polyacrylonitrile-butadiene (PAB), etc. 12

[0058] The sulfide solid-state electrolyte is one or more of Li-P-S-based electrolyte, Li6PS5Cl argyrodite, and sulfide crystalline lithium superionic conductor.

[0059] The battery anode uses common raw material types in the art, such as graphite-based carbon anode, silicon-based anode, metal oxide anode, lithium metal anode, and lithium metal alloy, etc.; the electrolyte uses common sulfide solid-state electrolyte in the art, which can be one or more of Li-P-S-based electrolyte, Li6PS5Cl argyrodite, and sulfide crystalline lithium superionic conductor.

[0060] The prepared full solid-state lithium ion battery is assembled into a full solid-state battery, and the assembled full solid-state battery is left to stand for 24 h before electrochemical performance testing. The voltage window for testing is 2.0-4.8 V (Li / Li + ), and the electrochemical performance of the battery is tested by using constant current charging and discharging.​

[0061] Example 1: A lithium-rich manganese-based all-solid-state lithium ion battery, comprising a positive electrode, a solid-state electrolyte and a negative electrode, is prepared as follows:

[0062] First, the positive electrode is prepared:

[0063] (1) Preparation of a layered lithium-rich manganese positive electrode material: 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3 lithium-rich manganese active material is blended with stable coating layer raw material LiNbO3 dissolved in ethanol, and then dried. The stable coating layer originally dissolved in the solvent is coated on the surface of the layered lithium-rich manganese positive electrode material as the solvent evaporates. Then, the layered lithium-rich manganese positive electrode material coated with the stable coating layer is mixed with a sulfide solid-state electrolyte Li6PS5Cl solution and dried again to form a double-coated layered lithium-rich manganese positive electrode material. The content of the stable coating layer raw material and the sulfide solid-state electrolyte is 2% of the mass of the lithium-rich manganese active material, respectively.

[0064] The thickness of the stable coating layer on the surface of the prepared layered lithium-rich manganese positive electrode material and the sulfide solid-state electrolyte coating layer is 15 nm and 20 nm, respectively.

[0065] (2) The double-coated positive electrode active material, the sulfide solid-state electrolyte and the conductive agent (mass ratio of 60:35:5) are ground and mixed for 1 hour. After uniform mixing, the powder is cold-pressed through a mold to prepare a positive electrode for an all-solid-state lithium ion battery. The pressure is 50 MPa and the time is 5 min.

[0066] Then assemble the battery:

[0067] (1) Add 100 mg of Li6PS5Cl solid-state electrolyte powder into a PEEK mold, and press the powder electrolyte into a round sheet under a pressure of 120 MPa for 1 min;

[0068] (2) Set the positive electrode on one side of the electrolyte round sheet, and press for 3 min under a pressure of 510 MPa;

[0069] (3) Add a piece of 100 μm thick indium sheet and a piece of 50 μm thick lithium sheet on the other side of the electrolyte round sheet, respectively.

[0070] The test results of the assembled all-solid-state battery are as follows: linear scanning is performed on the battery, and then the electronic conductivity of the material can be obtained according to Ohm's law. The electronic and ionic conductivities of the 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3 positive electrode are 6.96×10-7 S cm -1 and 5.73 x 10 -8 S cm -1 ( Figure 1 and Figure 2 ).

[0071] Example 2

[0072] The preparation process of the positive sheet is basically the same as that of Example 1, the difference is only that the content of Co in the layered lithium-rich manganese is different, and 0.5LiNi 0.33 Co 0.33 Mn 0.33 O2-0.5Li2MnO3 lithium-rich manganese oxide is used as the positive material. The assembly and test conditions of the all-solid-state battery are the same as those of Example 1.

[0073] Figure 3 The electronic conductivity of lithium-rich manganese is measured by using an ion-blocking battery, and Figure 4 The ion conductivity of lithium-rich manganese is measured by using an electron-blocking battery. It can be seen that the electronic conductivity of the typical lithium-rich manganese material 0.5LiNi 0.33 Co 0.33 Mn 0.33 O2-0.5Li2MnO3 is 3.52 x 10 -9 S cm -1 , and the ion conductivity is 2.65 x 10 -10 S cm -1 , which are very low. In comparison, the electronic and ion conductivities of the 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3 positive electrode are improved by two orders of magnitude.

[0074] Example 3

[0075] The preparation process of the positive sheet is basically the same as that of Example 1, the difference is only that the content of Co in the layered lithium-rich manganese is different, and 0.5LiNi 0.33 Co 0.38 Mn 028 O2-0.5Li2MnO3 lithium-rich manganese oxide is used as the positive material. The assembly and test conditions of the all-solid-state battery are the same as those of Example 1.

[0076] Figure 5 The electronic conductivity of lithium-rich manganese is measured by using an ion-blocking battery, and Figure 6The electronic conductivity of Li-rich manganese was measured by using the ion-blocking cell. It can be seen that the electronic conductivity of 0.5LiNi 0.33 Co 0.38 Mn 028 O2-0.5Li2MnO3 is 6.7x10 -8 S·cm -1 , and the ionic conductivity is 2.63x10 -9 S·cm -1 .

[0077] Example 4

[0078] The preparation process of the positive electrode sheet is basically the same as that of Example 1, and the only difference is that the content of Co in the layered Li-rich manganese is different. The Li-rich manganese oxide of 0.5LiNi 0.33 Co 0.48 Mn 018 O2-0.5Li2MnO3 is used as the positive electrode material. The assembly and test conditions of the all-solid-state battery are the same as those of Example 1.

[0079] Figure 7 The electronic conductivity of Li-rich manganese was measured by using the ion-blocking cell, and Figure 8 The ionic conductivity of Li-rich manganese was measured by using the electronic-blocking cell. It can be seen that the electronic conductivity of 0.5LiNi 0.33 Co 0.48 Mn 018 O2-0.5Li2MnO3 is 3.86x10 -6 S·cm -1 , and the ionic conductivity is 3.82x10 -7 S·cm -1 .

[0080] Example 5

[0081] The preparation process of the positive electrode sheet is basically the same as that of Example 1, and the only difference is that the content of Co in the layered Li-rich manganese is different. The Li-rich manganese oxide of 0.5LiNi 0.33 Co 0.53 Mn 013 O2-0.5Li2MnO3 is used as the positive electrode material. The assembly and test conditions of the all-solid-state battery are the same as those of Example 1.

[0082] Figure 9 The electronic conductivity of Li-rich manganese was measured by using the ion-blocking cell, and Figure 10 The ionic conductivity of Li-rich manganese was measured by using the electronic-blocking cell. It can be seen that the electronic conductivity of 0.5LiNi0.33 Co 0.53 Mn 013 The electronic conductivity of O2-0.5Li2MnO3 is 1.61×10⁻⁵. -5 S·cm -1 The ionic conductivity is 1.65 × 10⁻⁶. -6 S·cm -1 .

[0083] Example 6

[0084] The preparation process of the positive electrode is basically the same as that in Example 1, except that the Co content in the layered lithium-rich manganese is different. A 0.5LiNi electrode with a double coating of LiNbO3 and Li6PS5Cl sulfide electrolyte is used. 0.33 Co 0.58 Mn 0.08 A lithium-rich manganese oxide, O2-0.5Li2MnO3, was used as the cathode material. The assembly and testing conditions for the all-solid-state battery were the same as in Example 1.

[0085] Figure 11 The electronic conductivity of lithium-rich manganese was measured using an ion-blocking battery. Figure 12 The ionic conductivity of lithium-rich manganese was measured using an electron-blocking battery. It can be seen that 0.5LiNi 0.33 Co 0.58 Mn 0.08 The electronic conductivity of O2-0.5Li2MnO3 is 3.68×10⁻⁵. -5 S·cm -1 The ionic conductivity is 2.89 × 10⁻⁶. -6 S·cm -1 .

[0086] Example 7

[0087] The preparation process of the positive electrode is basically the same as that in Example 1, except that the Co content in the layered lithium-rich manganese is different. A 0.5LiNi electrode with a double coating of LiNbO3 and Li6PS5Cl sulfide electrolyte is used. 0.33 Co 0.66 A lithium-rich manganese oxide, O2-0.5Li2MnO3, was used as the cathode material. The assembly and testing conditions for the all-solid-state battery were the same as in Example 1.

[0088] Figure 13 The electronic conductivity of lithium-rich manganese was measured using an ion-blocking battery. Figure 14 The ionic conductivity of lithium-rich manganese was measured using an electron-blocking battery. It can be seen that 0.5LiNi 0.33 Co 0.66 The electronic conductivity of O2-0.5Li2MnO3 is 1.78×10⁻⁵.-4 S cm -1 , the ionic conductivity is 1.4 x 10 -5 S cm -1 .

[0089] Example 8:

[0090] A lithium-rich manganese-based all-solid-state lithium ion battery, the preparation process is different from that of Example 1 in that LiNiO2 composition is added to the layered lithium-rich manganese, and 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.05LiNiO2 lithium-rich manganese active material is coated with LiNbO3 and Li6PS5Cl sulfide electrolyte.

[0091] The assembly and test conditions of the all-solid-state battery are the same as those of Example 1.

[0092] Figure 15 The electronic conductivity of lithium-rich manganese was measured using an ion-blocking battery, and Figure 16 The ionic conductivity of lithium-rich manganese was measured using an electron-blocking battery. It can be seen that the electronic conductivity of 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.05LiNiO2 is 1.82 x 10 -5 S cm -1 , the ionic conductivity is 1.86 x 10 -6 S cm -1 .

[0093] Figure 17 The charge-discharge curve of the battery assembled in this example at a current density of 0.5C, 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.05LiNiO2 cathode has a discharge specific capacity of up to 195.5mAh·g -1 at 0.5C, the capacity retention rate is as high as 85% after 300 cycles, and the capacity retention rate is still 62% after 700 cycles, which is due to the high electronic and ionic conductivity, and the spinel phase formed on the surface is more conducive to lithium ion diffusion.

[0094] Example 9:

[0095] A lithium-rich manganese-based all-solid-state lithium ion battery was prepared in the same manner as in Example 1, except that LiNiO2 was added to the layered lithium-rich manganese, and 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.1LiNiO2 lithium-rich manganese oxide was used as the positive electrode material. The all-solid-state battery was assembled and tested under the same conditions as in Example 1.

[0096] Figure 18 The electronic conductivity of the lithium-rich manganese was measured using an ion-blocking cell, and the results are shown in Table 1. Figure 19 The ion conductivity of the lithium-rich manganese was measured using an electron-blocking cell. As can be seen from Table 1, the electronic conductivity of 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.1LiNiO2 was 7.36 x 10 -5 S·cm -1 , and the ion conductivity was 5.96 x 10 -6 S·cm -1 .

[0097] Figure 20 The charge-discharge curve of the battery assembled in this example at a current density of 0.5C is shown in Figure 1. The 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.1LiNiO2 positive electrode had a discharge capacity of 160.0 mAh·g -1 at 0.5C, and the capacity hardly decreased during long-term cycling, with a capacity retention rate of up to 90% after 700 cycles.

[0098] Example 10

[0099] The positive electrode sheet was prepared in the same manner as in Example 1, except that LiNiO2 was added to the layered lithium-rich manganese, and 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.03LiNiO2 lithium-rich manganese oxide was used as the positive electrode material. The all-solid-state battery was assembled and tested under the same conditions as in Example 1.

[0100] Figure 21 The electronic conductivity of the lithium-rich manganese was measured using an ion-blocking cell, and the results are shown in Table 1. Figure 22The ionic conductivity of lithium-rich manganese was measured using an electron-blocking battery. It can be seen that 0.5LiNi 0.33 Co 0.43 Mn 0.23 The electronic conductivity of O2-0.5Li2MnO3-0.03LiNiO2 is 1.05×10⁻⁶. -5 S·cm -1 The ionic conductivity is 4.83 × 10⁻⁶. -7 S·cm -1 .

[0101] Example 11

[0102] The preparation process of the positive electrode is basically the same as in Example 1, except that LiNiO2 is added to the layered lithium-rich manganese, and 0.5LiNiO2 is used as the double-coated electrolyte consisting of LiNbO3 and Li6PS5Cl sulfide. 0.33 Co 0.43 Mn 0.23 A lithium-rich manganese oxide compound consisting of O2-0.5Li2MnO3-0.07LiNiO2 was used as the cathode material. The assembly and testing conditions for the all-solid-state battery were the same as in Example 1.

[0103] Figure 23 The electronic conductivity of lithium-rich manganese was measured using an ion-blocking battery. Figure 24 The ionic conductivity of lithium-rich manganese was measured using an electron-blocking battery. It can be seen that 0.5LiNi 0.33 Co 0.43 Mn 0.23 The electronic conductivity of O2-0.5Li2MnO3-0.07LiNiO2 is 2.78×10⁻⁶. -5 S·cm -1 The ionic conductivity is 3.28 × 10⁻⁶. -6 S·cm -1 .

[0104] The above embodiment 9 is the best embodiment.

[0105] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for producing a structurally stable all-solid-state lithium-ion battery, characterized by: The preparation method of the positive electrode is First, a layered lithium-rich manganese positive electrode material is prepared: the lithium-rich manganese active material is blended with a stable coating layer raw material and then dried; the stable coating layer originally dissolved in the solvent is coated on the surface of the lithium-rich manganese active material as the solvent evaporates; then the lithium-rich manganese active material coated with the stable coating layer is mixed with a sulfide solid electrolyte solution and dried again to form a double-coated layered lithium-rich manganese positive electrode material; the content of the stable coating layer raw material and the sulfide solid electrolyte is 1-3% of the mass of the lithium-rich manganese active material; Then, the double-coated layered lithium-rich manganese positive electrode material, the sulfide electrolyte, and the conductive agent are ground and mixed for 0.5-1 hours, and after uniform mixing, the powder is cold-pressed through a mold to prepare a positive electrode for a full-solid-state lithium ion battery; the cold-pressing pressure is 50-150 MPa, and the time is 1-5 min; the mass ratio of the lithium-rich manganese positive electrode material, the sulfide solid electrolyte, and the conductive agent is 60:35:5; The battery assembly process is as follows: first, 100 mg of Li6PS5Cl solid electrolyte powder is added to a tablet pressing mold, and the powder electrolyte is pressed into a raw tablet under a pressure of 100-120 MPa for 1-2 min; then the positive electrode for the full-solid-state lithium ion battery is arranged on one side of the electrolyte raw tablet under a pressure of 500-600 MPa for 2-4 min; finally, a 100 μm thick indium sheet and a 50 μm thick lithium sheet are added on the other side of the electrolyte raw tablet, respectively. said lithium-rich manganese active material is selected from the group consisting of 0.5LiNi 0.33 Co 0.43 Mn 0.23 O2-0.5Li2MnO3-0.1LiNiO2; The stable coating layer is selected from LiNbO3, and the sulfide solid electrolyte coating layer is selected from Li6PS5Cl sulfide electrolyte.

2. The method of claim 1, wherein the method is characterized by: The thickness of the stable coating layer on the surface of the lithium-rich manganese active material and the sulfide solid electrolyte coating layer is 1-50 nm.

3. The method of claim 2, wherein the method further comprises: forming a plurality of lithium ion conductive layers on the substrate; and forming a plurality of lithium ion conductive layers on the plurality of lithium ion conductive layers. The thickness of the stable coating layer on the surface of the lithium-rich manganese active material and the sulfide solid electrolyte coating layer is 2-20 nm.

4. A full-solid-state lithium ion battery with a stable structure prepared by the preparation method of claim 1.

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