A method for coating modified lithium nickel manganese oxide by joule heat flash evaporation and a preparation method thereof

Abstract

The application discloses a kind of lithium nickel manganese oxide coated by Joule heat flash evaporation method and preparation method thereof, belong to lithium ion battery cathode material technical field, provide a kind of sulfide solid electrolyte coated lithium nickel manganese oxide cathode material, solve the compatibility of lithium nickel manganese oxide cathode material and electrolyte, improve battery cycle performance, reduce the expansion of battery caused by the oxygen release of cathode material surface.The application also provides a method for coating sulfide solid electrolyte on lithium nickel manganese oxide cathode material, and the method is Joule heat flash evaporation method.In the Joule heat reactor, the solid-state sulfide electrolyte precursor is rapidly sublimated and deposited on the surface of the cathode material by adsorption, and the lithium nickel manganese oxide cathode material coated with sulfide solid electrolyte is obtained.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium ion battery cathode materials, and particularly relates to a lithium nickel manganese oxide coated by a Joule heat flash evaporation method and a preparation method thereof. BACKGROUND

[0002] Lithium ion batteries have high working voltage, long cycle life, small self-discharge and other advantages, and have been widely used in the fields of digital products, electric tools, electric vehicles and energy storage power stations. The cathode material is one of the key materials of lithium ion batteries, and directly affects the energy density, power density and production cost of the battery. High-voltage lithium nickel manganese oxide has a voltage platform of 4.7V and a theoretical specific capacity of 147mAh / g, and does not contain expensive metal cobalt elements, which is one of the most ideal cathode materials for the next generation of lithium ion batteries. However, the lithium nickel manganese oxide cathode material still has problems such as electrolyte decomposition at high voltage, poor compatibility between the material and the electrolyte, manganese ion dissolution, and cell swelling, which will cause the cycle performance of the battery to deteriorate. By improving the contact interface between the material and the electrolyte, i.e. coating a solid-state electrolyte on the surface of the material, the cycle performance of the battery can be effectively improved, and the rate performance of the material can also be improved.

[0003] Some coating technologies for lithium nickel manganese oxide cathode materials are also disclosed in the prior art. For example, patent CN105374997B discloses a preparation method for coating lithium nickel manganese oxide with a composite material, which adds a calcium salt, a zirconium salt and a titanium salt composite solution to a lithium nickel manganese oxide precursor suspension, uses PEG as a dispersing agent and citric acid as a complexing agent, and obtains a CaO, ZrO2 and TiO2 coated lithium nickel manganese oxide precursor by mechanical stirring and constant temperature water bath reaction in an ammonia solution with a pH value. Then, the coated lithium nickel manganese oxide composite material is obtained by calcination and annealing treatment in an air atmosphere. Patent CN109817968B discloses lithium nickel manganese oxide particles coated on the surface and a manufacturing method thereof. Coating lithium vanadate on the surface of lithium nickel manganese oxide can prevent direct contact between the material and the electrolyte, alleviate the disproportionation reaction of Mn 3+ and the oxidation of Mn 4+ , alleviate the cell swelling problem, and improve the battery capacity and the initial coulomb efficiency.

[0004] At high voltage, the electrolyte LiPF6 will react with trace amounts of water in the electrolyte to produce HF, thereby causing the dissolution of manganese ions, which precipitate on the surface of the electrode in the form of metal particles, which is the main cause of the deterioration of the cycle performance of the material. At the same time, the dissolution of manganese ions will cause the oxygen release reaction to occur on the surface of the cathode material, and the released oxygen will react with the electrolyte to produce gas, which is the main cause of the cell swelling.

[0005] The existing coating technology mainly uses inorganic oxides and phosphates to protect the surface of the positive electrode material, which cannot effectively inhibit the side reaction caused by trace water in the electrolyte and cannot effectively inhibit the release of oxygen on the surface of the positive electrode material.

[0006] In 2020, James M. Tour et al. proposed a flash Joule heat technology, which uses the high voltage, large current and large power provided by the capacitor to instantaneously heat up to prepare graphene (Luong D X, Bets K V, Algozeeb W A, et al. Gram-scale bottom-up flash graphene synthesis [J]. Nature, 2020, 577(7792): 647-651.). The person skilled in the art urgently needs to develop a Joule heat flash method for coating modified lithium nickel manganese oxide and a preparation method thereof to meet the existing application market and performance requirements. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides a sulfide solid electrolyte coated lithium nickel manganese oxide positive electrode material, which aims to solve the compatibility of lithium nickel manganese oxide positive electrode material and electrolyte, improve the cycle performance of the battery and reduce the expansion of the battery caused by the release of oxygen on the surface of the positive electrode material.

[0008] The present application also provides a method for coating a sulfide solid electrolyte on a lithium nickel manganese oxide positive electrode material, which is a Joule heat flash method. In a Joule heat reactor, the solid sulfide electrolyte precursor is rapidly sublimed and deposited on the surface of the positive electrode material to obtain a sulfide solid electrolyte coated lithium nickel manganese oxide positive electrode material.

[0009] A Joule heat flash method for coating modified lithium nickel manganese oxide material, comprising lithium nickel manganese oxide and a sulfide solid electrolyte coated on the surface of the lithium nickel manganese oxide; the sulfide solid electrolyte has a chemical formula of LiaM’bM”cSd, wherein M’ is a positive tetravalent element; M” is a positive pentavalent element; the ratio of each component in the chemical formula is a+4b+5c=2d.

[0010] Further, the thickness of the sulfide solid electrolyte is 10-200 nm.

[0011] Further, the M’ is a positive tetravalent element, which is one or more of Si, Ge, Sn and Pb; and the M” is a positive pentavalent element, which is one or more of P, As and Sb. Preferably, the M’ is a positive tetravalent element, which is one or more of Si, Ge and Sn; and the M” is a positive pentavalent element, which is one or more of P and Sb. More preferably, the M’ is a positive tetravalent element, which is one or more of Si and Ge; and the M” is a positive pentavalent element, which is P.

[0012] Further, the Li a M' b M" c S d including but not limited to Li2S, Li3PS4, Li5PS5, Li7PS6, Li7P3S 11 , Li8P2S9, Li4SiS4, Li4GeS4, Li4SnS4, Li4PbS4, Li7SiPS8, Li 10 SiP2S 12 , Li7GePS8, Li 11 GePS 10 , Li 10 GeP2S 12 , Li 13 GeP3S 16 , Li7SnPS8, Li 10 SnP2S 12 , Li7PbPS8, Li 10 PbP2S 12 , Li7SiSbS8, Li 10 SiSb2S 12 , Li7PbSbS8, Li 10 PbSb2S 12 , Li7SiSbS8, Li 10 SiSb2S 12 , Li7SiSb 0.4 P 0.6 S8, Li 10 SiSb 0.8 P 1.2 S 12 , Li7Si 0.2 Ge 0.8 As 0.2 P 0.8 S8, Li 10 Sn 0.1 Ge 0.9 As 0.1 P 1.9 S 12 , Li7Si 0.2 Ge 0.8 Sb 0.4 P 0.6 S8, Li 10 Sn 0.1 Ge 0.9 Sb 0.8 P 1.2 S 12 . Preferably, the Li a M' b M" c Sd Including but not limited to Li2S, Li3PS4, Li5PS5, Li7PS6, and Li7P3S 11 , Li8P2S9, Li4SiS4, Li4GeS4, Li4SnS4, Li4PbS4, Li7SiPS8, Li 10 SiP2S 12 Li7GePS8, Li 11 GePS 10 Li 10 GeP2S 12 Li 13 GeP3S 16 Li7SnPS8, Li 10 SnP2S 12 Li7SiSbS8, Li 10 SiSb2S 12 Li7SiSbS8, Li 10 SiSb2S 12 Li7SiSb 0.4 P 0.6 S8, Li 10 SiSb 0.8 P 1.2 S 12 Li7Si 0.2 Ge 0.8 Sb 0.4 P 0.6 S8, Li 10 Sn 0.1 Ge 0.9 Sb 0.8 P 1.2 S 12 One or more of the following. More preferably, the Li a M' b M” c S d Including but not limited to Li3PS4, Li5PS5, Li7PS6, and Li7P3S 11 , Li8P2S9, Li4SiS4, Li4GeS4, Li7SiPS8, Li 10 SiP2S 12 Li7GePS8, Li 11 GePS 10 Li 10 GeP2S 12 Li 13 GeP3S 16 Li7SiSb 0.4 P 0.6 S8, Li 10 SiSb0.8 P 1.2 S 12 Li7Si 0.2 Ge 0.8 Sb 0.4 P 0.6 S8, Li 10 Sn 0.1 Ge 0.9 Sb 0.8 P 1.2 S 12 One or more of them.

[0013] The above-mentioned method for preparing modified nickel-manganese lithium oxide material by Joule thermal flash evaporation is characterized by comprising the following steps:

[0014] A) Lithium sulfide, M'-containing sulfide, and M”-containing sulfide are mixed evenly and then pressed into a blank;

[0015] B) Place the billet and lithium nickel manganese oxide matrix into a Joule thermal reactor, and adjust the current intensity, pulse time and reaction time through the billet under vacuum to make the billet sublimate under the Joule thermal effect.

[0016] C) The sublimated preform material forms a uniform coating layer on the surface of the lithium nickel manganese oxide matrix;

[0017] D) After cooling, lithium nickel manganese oxide cathode material coated with sulfide solid electrolyte.

[0018] Furthermore, the M'-containing sulfide is selected from one or more of silicon sulfide, germanium sulfide, tin sulfide, and lead sulfide; the M"-containing sulfide is selected from one or more of phosphorus sulfide, antimony sulfide, and arsenic sulfide. Preferably, the M'-containing sulfide is selected from one or more of SiS, SiS2, GeS, GeS2, SnS, SnS2, PbS, and PbS2; the M"-containing sulfide is selected from P4S3, P4S5, and P4S 10 As4S3, As4S5, As4S 10 Sb4S3, Sb4S5, Sb4S 10 One or more of the following. More preferably, the M'-containing sulfide is selected from one or more of SiS, SiS2, GeS, GeS2, SnS, and SnS2; the M"-containing sulfide is selected from P4S3, P4S5, and P4S... 10 Sb4S3, Sb4S5, Sb4S 10 One or more of them.

[0019] Furthermore, the mixing ratio of lithium sulfide, M'-containing sulfide, and M"-containing sulfide is in accordance with the chemical formula Li a M' b M” c S dThe molar ratio is calculated in the formula.

[0020] Further, the current intensity through the blank body is 0-500 A, the pulse time is 1-100 ms, and the reaction time is 0.1-300 s. Preferably, the current intensity through the blank body is 10-300 A, the pulse time is 1-50 ms, and the reaction time is 5-200 s. More preferably, the current intensity through the blank body is 100-200 A, the pulse time is 5-40 ms, and the reaction time is 5-30 s.

[0021] Due to the inevitable absorption of water in the air by the electrolyte during production, transportation and storage, the electrolyte contains a small amount of water molecules. The sulfur-containing solid-state electrolyte can react with a small amount of water to generate lithium hydroxide and lithium hydrogen sulfate salt, removing the trace water in the electrolyte and avoiding the generation of HF, and reducing the deterioration of the material cycle performance caused by the dissolution of manganese ions. Take Li2S as an example, the specific reaction equation is as follows: H2O+Li2S=LiHS+LiOH; take Li3PS4 as an example, the specific reaction equation is as follows: H2O+Li3PS4=Li2PHS4+LiOH; take Li 10 GeP2S 12 As an example, the specific reaction equation is as follows: H2O+Li 10 GeP2S 12 =Li9GeP2HS 12 +LiOH; the reaction mechanism of other sulfur-containing solid-state electrolytes is consistent with the above compounds. If oxygen release occurs on the surface of the lithium nickel manganese oxide positive electrode material, it will first undergo an oxidation reaction with the sulfur-containing solid-state electrolyte, avoiding the gas production caused by the side reaction of oxygen and electrolyte, and effectively inhibiting the swelling of the battery.

[0022] Compared with the existing positive electrode material coating technology, the Joule heat flash evaporation method directly utilizes the in-situ heating of the internal resistance of the solid-state electrolyte itself, can produce instantaneous high temperature in a very short time, makes the solid-state electrolyte flash evaporate and deposit on the surface of the lithium nickel manganese oxide substrate, has the advantages of high reaction temperature, fast heating rate, short reaction time and low energy consumption. A low-porosity, uniform and thin coating layer can be formed on the surface of the lithium nickel manganese oxide substrate, effectively improving the lithium ion transference rate of the surface of the lithium nickel manganese oxide positive electrode material. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a scanning electron microscope graph of Example 1; Figure 2 It is a comparison graph of the cycle performance curves of the batteries made of Example 1, Comparative Example 1 and Comparative Example 2. DETAILED DESCRIPTION Example 1

[0024] S1: Li2S, SiS2, Sb4S 10, P4S 10 After mixing uniformly according to the molar ratio 5:1:0.2:0.3, the blank is pressed;

[0025] S2: The blank and the lithium nickel manganese oxide base are placed into a joule heat reactor, and the current intensity through the blank is adjusted to 100 A under vacuum, the pulse time is 0.5 ms, and the reaction time is 10 s, so that the blank is sublimated under the joule heat effect;

[0026] S3: The sublimated blank material forms a uniform coating layer with a thickness of 20 nm on the surface of the lithium nickel manganese oxide base;

[0027] S4: After cooling, the sulfide solid electrolyte coated lithium nickel manganese oxide positive electrode material is Li 10 SiSb 0.8 P 1.2 S 12 coated lithium nickel manganese oxide positive electrode material.

[0028] Figure 1 The scanning electron microscope image of the sulfide solid electrolyte coated lithium nickel manganese oxide positive electrode material prepared in Example 1 is shown in the accompanying Figure 1 It can be seen that the particle size distribution of the lithium nickel manganese oxide positive electrode material prepared in Example 1 is uniform, and the surface is relatively smooth. Example 2

[0029] S1: Li2S, SnS2, GeS2, Sb4S 10 , P4S 10 After mixing uniformly according to the molar ratio 5:0.1:0.9:0.2:0.3, the blank is pressed;

[0030] S2: The blank and the lithium nickel manganese oxide base are placed into a joule heat reactor, and the current intensity through the blank is adjusted to 150 A under vacuum, the pulse time is 0.1 ms, and the reaction time is 8 s, so that the blank is sublimated under the joule heat effect;

[0031] S3: The sublimated blank material forms a uniform coating layer with a thickness of 30 nm on the surface of the lithium nickel manganese oxide base;

[0032] S4: After cooling, the sulfide solid electrolyte coated lithium nickel manganese oxide positive electrode material is Li 10 Sn 0.1 Ge 0.9 Sb 0.8 P 1.2 S 12 of the lithium nickel manganese oxide positive electrode material. Example 3

[0033] S1: Li2S, SnS2, GeS2, As4S 10 , P4S 10Mixing uniformly according to the molar ratio of 5:0.1:0.9:0.025:0.475, and then pressing into a green body;

[0034] S2: Put the green body and the lithium nickel manganese oxide matrix into a joule heat reactor, adjust the current intensity through the green body to 200 A, the pulse time to 5 ms, and the reaction time to 15 s under vacuum, so that the green body sublimates under the joule heat effect;

[0035] S3: The sublimated green body material forms a uniform coating layer with a thickness of 50 nm on the surface of the lithium nickel manganese oxide matrix;

[0036] S4: After cooling, the sulfide solid-state electrolyte Li 10 Sn 0.1 Ge 0.9 As 0.1 P 1.9 S 12 coated lithium nickel manganese oxide positive electrode material. Example 4

[0037] S1: Mix Li2S, SiS2, Sb4S 10 Mix uniformly according to the molar ratio of 5:1:0.5, and then press into a green body;

[0038] S2: Put the green body and the lithium nickel manganese oxide matrix into a joule heat reactor, adjust the current intensity through the green body to 250 A, the pulse time to 10 ms, and the reaction time to 10 s under vacuum, so that the green body sublimates under the joule heat effect;

[0039] S3: The sublimated green body material forms a uniform coating layer with a thickness of 25 nm on the surface of the lithium nickel manganese oxide matrix;

[0040] S4: After cooling, the sulfide solid-state electrolyte Li 10 SiSb2S 12 coated lithium nickel manganese oxide positive electrode material. Example 5

[0041] S1: Mix Li2S and GeS2 uniformly according to the molar ratio of 2:1, and then press into a green body;

[0042] S2: Put the green body and the lithium nickel manganese oxide matrix into a joule heat reactor, adjust the current intensity through the green body to 400 A, the pulse time to 0.5 ms, and the reaction time to 30 s under vacuum, so that the green body sublimates under the joule heat effect;

[0043] S3: The sublimated green body material forms a uniform coating layer with a thickness of 80 nm on the surface of the lithium nickel manganese oxide matrix;

[0044] S4: After cooling, the sulfide solid-state electrolyte Li4GeS4 coated lithium nickel manganese oxide positive electrode material. Example 6

[0045] S1: Li2S, P4S 10 After mixing uniformly according to the molar ratio 1.5:0.25, the blank is pressed;

[0046] S2: The blank and the lithium nickel manganese oxide base are placed into a joule heat reactor, and the current intensity through the blank is adjusted to 300 A under vacuum, the pulse time is 10 ms, and the reaction time is 20 s, so that the blank is sublimated under the joule heat effect;

[0047] S3: The sublimated blank material forms a uniform coating layer with a thickness of 20 nm on the surface of the lithium nickel manganese oxide base;

[0048] S4: After cooling, the sulfide solid electrolyte coated lithium nickel manganese oxide positive electrode material is Li3PS4. Example 7

[0049] S1: Li2S, SiS2, GeS2, Sb4S 10 , P4S 10 After mixing uniformly according to the molar ratio 3.5:0.2:0.8:0.1:0.15, the blank is pressed;

[0050] S2: The blank and the lithium nickel manganese oxide base are placed into a joule heat reactor, and the current intensity through the blank is adjusted to 50 A under vacuum, the pulse time is 0.2 ms, and the reaction time is 150 s, so that the blank is sublimated under the joule heat effect;

[0051] S3: The sublimated blank material forms a uniform coating layer with a thickness of 40 nm on the surface of the lithium nickel manganese oxide base;

[0052] S4: After cooling, the sulfide solid electrolyte Li7Si 0.2 Ge 0.8 Sb 0.4 P 0.6 S8 coated lithium nickel manganese oxide positive electrode material. Example 8

[0053] S1: Li2S, GeS2, P4S 10 After mixing uniformly according to the molar ratio 5:1:0.5, the blank is pressed;

[0054] S2: The blank and the lithium nickel manganese oxide base are placed into a joule heat reactor, and the current intensity through the blank is adjusted to 180 A under vacuum, the pulse time is 5 ms, and the reaction time is 25 s, so that the blank is sublimated under the joule heat effect;

[0055] S3: The sublimated blank material forms a uniform coating layer with a thickness of 15 nm on the surface of the lithium nickel manganese oxide base;

[0056] S4: After cooling, the sulfide solid-state electrolyte Li4GeS4-coated lithium nickel manganese oxide positive electrode material. 10 GeP2S 12 The lithium nickel manganese oxide positive electrode material is coated. Example 9

[0057] S1: Li2S and GeS2 were mixed uniformly in a molar ratio of 2:1 and then pressed into a blank;

[0058] S2: The blank and the lithium nickel manganese oxide matrix were placed in a joule heat reactor, and the current intensity through the blank was adjusted to 500 A under vacuum, the pulse time was 100 ms, and the reaction time was 280 s, so that the blank was sublimated under the joule heat effect;

[0059] S3: The sublimated blank material formed a uniform coating layer with a thickness of 200 nm on the surface of the lithium nickel manganese oxide matrix;

[0060] S4: After cooling, the sulfide solid-state electrolyte Li4GeS4-coated lithium nickel manganese oxide positive electrode material. Example 10

[0061] S1: Li2S, P4S 10 and GeS2 were mixed uniformly in a molar ratio of 3.5:0.75 and then pressed into a blank;

[0062] S2: The blank and the lithium nickel manganese oxide matrix were placed in a joule heat reactor, and the current intensity through the blank was adjusted to 200 A under vacuum, the pulse time was 20 ms, and the reaction time was 20 s, so that the blank was sublimated under the joule heat effect;

[0063] S3: The sublimated blank material formed a uniform coating layer with a thickness of 10 nm on the surface of the lithium nickel manganese oxide matrix;

[0064] S4: After cooling, the sulfide solid-state electrolyte Li7P3S 11 -coated lithium nickel manganese oxide positive electrode material.

[0065] Comparative Example 1

[0066] The lithium nickel manganese oxide matrix material described in Example 1.

[0067] Comparative Example 2

[0068] S1: The lithium nickel manganese oxide matrix material was ultrasonically dispersed in isopropanol, and stirring was performed to obtain a lithium nickel manganese oxide suspension;

[0069] S2: according to Li:Ca:Zr:Ti=2:0.01:0.01:0.01, calcium acetate, zirconium hydroxide, tetrabutyl titanate are weighed and added into the lithium nickel manganese oxide suspension of step S1, 1% by mass of PEG is added as a dispersant, 1% by mass of citric acid is added as a complexing agent, ammonia is added dropwise to adjust the pH to 9, mechanical stirring is performed, and the reaction is carried out in a thermostatic water bath at 60°C for 1 h, then the product is taken out and aged for 2 h, and then the CaO-ZrO2-TiO2-coated lithium nickel manganese oxide precursor is obtained after filtration, washing and drying treatment;

[0070] S3: the CaO-ZrO2-TiO2-coated lithium nickel manganese oxide precursor of step S2 is calcined at 750°C for 4 h in an air atmosphere, and then annealed by cooling to 500°C for 4 h, to obtain the CaO-ZrO2-TiO2-coated lithium nickel manganese oxide composite material.

[0071] The batteries prepared from Example 1, Comparative Example 1 and Comparative Example 2 are subjected to normal temperature cycle performance test, and the results are shown in Table 1. Figure 2 The 1C discharge specific capacity of the battery prepared from Example 1 is 131.7 mAh / g, and the cycle capacity retention rate after 80 cycles is 96.9%; the 1C discharge specific capacity of the battery prepared from Comparative Example 1 is 130.2 mAh / g, and the cycle capacity retention rate after 80 cycles is 78.1%; the 1C discharge specific capacity of the battery prepared from Comparative Example 2 is 132.3 mAh / g, and the cycle capacity retention rate after 80 cycles is 87.5%; the normal temperature cycle performance of Example 1 is better than that of Comparative Examples 1 and 2.

[0072] The soft package batteries prepared from Examples 1-10, Comparative Example 1 and Comparative Example 2 are subjected to charge-discharge cycle, and the thicknesses of the soft package batteries before and after 20 weeks of cycle are compared; it can be seen from the thickness measurement results that the expansion rates of the batteries of Examples 1-10 are smaller than those of Comparative Examples 1 and 2.

[0073] The soft package batteries prepared from Examples 1-10, Comparative Example 1 and Comparative Example 2 are subjected to charge-discharge cycle, and the thicknesses of the soft package batteries before and after 20 weeks of cycle are compared; it can be seen from the thickness measurement results that the expansion rates of the batteries of Examples 1-10 are smaller than those of Comparative Examples 1 and 2.

[0074] Table 1 Expansion rates of the soft package batteries prepared from Examples 1-10, Comparative Example 1 and Comparative Example 2 after 20 weeks of cycle

[0075] .

Claims

1. A method of coating a modified lithium nickel manganese oxide material by Joule heating flash evaporation, characterized in that, The lithium nickel manganese oxide is coated with a sulfide solid electrolyte having a chemical formula of LiaM'bM"cSd, wherein M' is a tetravalent element, M" is a pentavalent element, and a+4b+5c=2d. The preparation method of the modified lithium nickel manganese oxide material coated by the joule heat flash evaporation method comprises the following steps: A) mixing lithium sulfide, M'-containing sulfide, and M"-containing sulfide uniformly and then pressing into a blank; B) placing the blank and a lithium nickel manganese oxide matrix into a joule heat reactor, adjusting the current intensity, pulse time, and reaction time through the blank under vacuum, so that the blank is sublimated under the joule heat effect; C) forming a uniform coating layer on the surface of the lithium nickel manganese oxide matrix after the sublimation of the blank material; D) after cooling, the lithium nickel manganese oxide anode material coated with the sulfide solid electrolyte.

2. The joule heating flash evaporation process coated modified lithium nickel manganese oxide material of claim 1, wherein, In the chemical formula LiaM'bM"cSd, M' is a tetravalent element. M" is a pentavalent element; and the ratio of each component in the chemical formula is a+4b+5c=2d.

3. The joule heating flash evaporation process coated modified lithium nickel manganese oxide material of claim 1, wherein, The thickness of the sulfide solid electrolyte is 10-200 nm.

4. The joule heating flash evaporation process coated modified lithium nickel manganese oxide material of claim 1, wherein, M' is one or more of tetravalent elements Si, Ge, Sn, and Pb.

5. The joule heating flash evaporation process coated modified lithium nickel manganese oxide material of claim 1, wherein, M" is one or more of pentavalent elements P, As, and Sb.

6. The joule heating flash evaporation process coated modified lithium nickel manganese oxide material of claim 1, wherein, The Li a M’ b M” c S d including, but not limited to, Li2S, Li3PS4, Li5PS5, Li7PS6, Li7P3S 11 , Li8P2S9, Li4SiS4, Li4GeS4, Li4SnS4, Li4PbS4, Li7SiPS8, Li 10 SiP2S 12 , Li7GePS8, Li 11 GePS 10 , Li 10 GeP2S 12 , Li 13 GeP3S 16 , Li7SnPS8, Li 10 SnP2S 12 , Li7PbPS8, Li 10 PbP2S 12 , Li7SiSbS8, Li 10 SiSb2S 12 , Li7PbSbS8, Li 10 PbSb2S 12 , Li7SiSbS8, Li 10 SiSb2S 12 , Li7SiSb 0.4 P 0.6 S8, Li 10 SiSb 0.8 P 1.2 S 12 , Li7Si 0.2 Ge 0.8 As 0.2 P 0.8 S8, Li 10 Sn 0.1 Ge 0.9 As 0.1 P 1.9 S 12 , Li7Si 0.2 Ge 0.8 Sb 0.4 P 0.6 S8, Li 10 Sn 0.1 Ge 0.9 Sb 0.8 P 1.2 S 12 .

7. A preparation method of the modified lithium nickel manganese oxide material coated by the joule heat flash evaporation method according to any one of claims 1-6.

8. The production method according to claim 7, characterized by, The M'-containing sulfide is selected from one or more of silicon sulfide, germanium sulfide, tin sulfide, and lead sulfide.

9. The preparation method according to claim 7, characterized in that, The mixing ratio of the lithium sulfide, the M' containing sulfide, and the M" containing sulfide is calculated according to the chemical formula Li a M' b M" c S d mole ratio.

10. The preparation method according to claim 7, characterized in that, The current intensity through the blank is 0-500 A, the pulse time is 1-100 ms, and the reaction time is 0.1-300 s.

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