Ternary positive electrode material prepared by high-temperature solid-phase sintering and atomic layer deposition and preparation method thereof

Abstract

This invention discloses a method for preparing ternary cathode materials using high-temperature solid-state sintering and atomic layer deposition (ALD). Specifically, the method involves wet impregnation coating to uniformly attach metal ions to the material surface, followed by vacuum drying and solid-state sintering to obtain a near-surface-doped cathode material. This material is then transferred to an ALD chamber for further coating, constructing a cathode material with synergistic regulation of the metal ion doping layer and the metal oxide coating layer. This invention also discloses the preparation method of this cathode material. This invention addresses the severe bulk structure decay and surface side reactions problems of high-nickel ternary cathode materials through the synergistic effect of the metal oxide coating layer and the metal ion doping layer, thereby improving capacity.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion secondary battery material technology, specifically relating to ternary cathode materials of high-temperature solid-state sintering and atomic layer deposition, and also to the preparation method of the material. Background Technology

[0002] Lithium-ion batteries, with their advantages of high energy density and long cycle life, have become the core power source for electric vehicles and large-scale energy storage systems. Nickel-cobalt-manganese (NCM) ternary cathode materials can balance high specific capacity and cost control by adjusting the ratio of nickel, cobalt, and manganese. Among them, high-nickel (Ni ≥ 0.8) materials have attracted much attention due to their high energy density.

[0003] However, high-nickel ternary cathode materials face more severe structural and interface failure problems than conventional ternary materials under deep delithiation and high-voltage (≥4.5V) cycling. On the one hand, Ni in high-nickel materials... 4+ Strong oxidizing properties exacerbate interfacial side reactions between the electrode and the electrolyte, leading to the dissolution of transition metals, electrolyte decomposition, and increased impedance. Furthermore, the irreversible H2-H3 phase transition during charging and discharging, accompanied by drastic changes in lattice volume, induces the propagation of microcracks in particles, accelerating electrical contact failure and structural collapse. In addition, high-nickel materials exhibit poor thermal stability and are prone to oxygen release reactions, posing a risk of thermal runaway.

[0004] To address these issues, researchers have developed two strategies: bulk doping and surface coating. Bulk doping (such as doping with Mg, Al, Ti, etc.) can stabilize the crystal lattice and suppress irreversible phase transitions, but it cannot eliminate interfacial side reactions. Surface coating can physically isolate the electrolyte. Traditional methods (sol-gel, co-precipitation, etc.) suffer from poor uniformity and difficulty in controlling thickness, while atomic layer deposition (ALD) technology can achieve precise thickness control at the atomic scale, forming a shape-preserving and dense coating layer. However, single coating can only protect the surface and is insufficient to suppress phase transitions and microcracks within the bulk phase; single doping cannot prevent surface electrolyte erosion. For high-nickel ternary materials, bulk structural decay is the fundamental problem, while surface side reactions are exacerbating factors; both are indispensable. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition, which solves the problem of bulk structure decay in existing high-nickel ternary cathode materials.

[0006] Another objective of this invention is to provide a method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition.

[0007] The technical solution adopted in this invention is a method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition. Specifically, metal ions are uniformly attached to the surface of the material by wet impregnation and coating. After vacuum drying, solid-state sintering is performed to obtain a cathode material with near-surface metal ion doping. Subsequently, the material is transferred to an ALD chamber for coating to construct a cathode material with synergistic regulation of metal ion doping layer and metal oxide coating layer.

[0008] The invention is further characterized in that, The specific steps are as follows: Step 1: Dissolve the metal-doped salt in anhydrous ethanol to prepare a doped ion precursor solution; Step 2: Disperse the NCM811 ternary cathode material in a doped salt ethanol solution and let it stand; Step 3: Vacuum dry the solution, and grind and mix the dried solid. Step 4: High-temperature solid-state sintering and grinding of the powder using a tube furnace; Step 5: Transfer the sintered ternary cathode material to the ALD chamber and fix it in the ALD reactor for vacuum drying, then purge with argon gas. Step 6: Inject the pulse of reaction precursor source 1 into the chamber; Step 7: After settling, purge the chamber with argon gas; Step 8: Inject the pulse of reaction precursor source 2 into the chamber; Step 9: After settling, purge the chamber with argon gas to complete one ALD cycle. Perform several cycles of steps 6-8 to complete M layers of different thicknesses. y O z The deposition of a coating layer, wherein M is Nb, Ti, Al, Zr, Zn, Fe, Mg, Ta, or La.

[0009] In step 1, the metal doped salt includes one of tetrabutyl titanate, aluminum nitrate nonahydrate, or zirconium oxychloride, with an addition amount of 0.2-0.5g, anhydrous ethanol of 50-150mL, and stirring time of 10-20min.

[0010] In step 2, the amount of NCM811 ternary cathode material is 5-15g, the dispersion time is 20-35min, and the standing time at room temperature is 2-4h.

[0011] In step 3, the vacuum temperature is 60-75℃, the time is 10-12h, and the grinding time is 1-1.5h.

[0012] In step 4, the sintering atmosphere is oxygen, the temperature is 400-500℃, the heating rate is 5℃ / min, and the grinding time is 1-1.5h.

[0013] In step 5, the amount of ternary cathode material taken after sintering is 50-150mg. The NCM811 ternary cathode material is ultrasonically cleaned, the transfer process takes 5-10min, the vacuum temperature is 60-75℃, and the argon purging time is 15s-25s.

[0014] In step 6, the precursor source 1 contains one of tetraisopropyl titanate, trimethylaluminum or tetradimethylaminozirconium, and the injection time is 0.04-0.06 s.

[0015] In step 8, the precursor source 2 is water, and the injection time is 0.04-0.06s.

[0016] Another technical solution adopted in this invention is a ternary cathode material prepared by a method of high-temperature solid-state sintering and atomic layer deposition.

[0017] The third technical solution adopted in this invention is a method for preparing a ternary positive electrode sheet. Specifically, it involves mixing ternary positive electrode material, conductive agent, and binder in a mass ratio of 8:1:1 with NMP in a glass bottle to obtain a positive electrode slurry. The positive electrode slurry is then coated onto a current collector and dried to obtain the ternary positive electrode sheet. The current collector is aluminum foil, the conductive agent is Super-P, and the adhesive is polyvinylidene fluoride. The beneficial effects of this invention are: The ternary cathode material prepared by this invention has a metal oxide coating layer and a metal ion doping layer. The metal oxide coating layer solves the problem of side reactions at the electrolyte / electrode interface, and the metal ion doping layer solves the serious bulk structure decay of high-nickel ternary cathode materials during charge and discharge. The two work together to achieve a significant breakthrough in capacity performance. Attached Figure Description

[0018] Figure 1 This is a TEM spectrum of the ternary cathode material prepared in Example 1 of this invention; Figure 2 This is a rate performance test diagram of lithium battery 1 and lithium battery D1 in this invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0020] The present invention discloses a method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition, specifically as follows: metal ions are uniformly attached to the surface of the material by wet impregnation and coating, and after vacuum drying, solid-state sintering is performed to obtain a cathode material with near-surface metal ion doping. Subsequently, the material is transferred to an ALD chamber for coating to construct a cathode material with synergistic regulation of metal ion doping layer and metal oxide coating layer.

[0021] The specific steps are as follows: Step 1: Dissolve the metal-doped salt in anhydrous ethanol to prepare a doped ion precursor solution; The metal doped salt includes one of tetrabutyl titanate, aluminum nitrate nonahydrate or zirconium oxychloride, with an addition amount of 0.2-0.5g, anhydrous ethanol of 50-150mL, and stirring time of 10-20min. Step 2: Disperse the NCM811 ternary cathode material in a doped salt ethanol solution and let it stand; The NCM811 ternary cathode material is 5-15g, the dispersion time is 20-35min, and the standing time at room temperature is 2-4h; Step 3: Vacuum dry the solution, and grind and mix the dried solid. The vacuum temperature is 60-75℃, the time is 10-12h, and the grinding time is 1-1.5h. Step 4: High-temperature solid-state sintering and grinding of the powder using a tube furnace; The sintering atmosphere is oxygen, the temperature is 400-500℃, the heating rate is 5℃ / min, and the grinding time is 1-1.5h. Step 5: Transfer the sintered ternary cathode material to the ALD chamber and fix it in the ALD reactor for vacuum drying, then purge with argon gas. The amount of ternary cathode material taken after sintering is 50-150mg. The NCM811 ternary cathode material is ultrasonically cleaned, the transfer process takes 5-10min, the vacuum temperature is 60-75℃, and the argon purging time is 15s-25s. Step 6: Inject the pulse of reaction precursor source 1 into the chamber; Precursor source 1 contains one of tetraisopropyl titanate (TTIP), trimethylaluminum (TMA), or tetradimethylaminozirconium (TDMAZ), and the injection time is 0.04-0.06 s. Step 7: After settling, purge the chamber with argon gas; Step 8: Inject the pulse of reaction precursor source 2 into the chamber; Precursor source 2 is water, and the injection time is 0.04-0.06s.

[0022] Step 9: After settling, purge the chamber with argon gas to complete one ALD cycle. Perform several cycles of steps 6-8 to complete M layers of different thicknesses. y O z The deposition of a coating layer, wherein M is Nb, Ti, Al, Zr, Zn, Fe, Mg, Ta, or La.

[0023] The preparation method of the ternary positive electrode sheet uses ternary positive electrode material. Specifically, the ternary positive electrode material, conductive agent and binder in a mass ratio of 8:1:1 are mixed evenly with NMP in a glass bottle to obtain a positive electrode slurry. The positive electrode slurry is coated on a current collector and dried to obtain a ternary positive electrode sheet. The current collector is aluminum foil, the conductive agent is Super-P, and the adhesive is polyvinylidene fluoride.

[0024] The present invention also provides a lithium battery, wherein the positive electrode is a ternary positive electrode sheet; the negative electrode is a lithium wafer; the electrolyte is LiPF6 as the solute and a mixed solvent of ethylene carbonate (EC), dimethyl carbonate (EMC) and diethyl carbonate (DEC), with 2% ethylene carbonate (VC) and 10% fluoroethylene carbonate (FEC) added; and the separator is Celgard 2325.

[0025] Example 1 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Add 0.38g of tetrabutyl titanate to 100mL of anhydrous ethanol and stir magnetically for 15min; Step 2: Dissolve 10g of NCM811 ternary cathode material in doped ion precursor solution, ultrasonically disperse for 30min, and let stand for 3h. Step 3: Dry the solution from Step 2 under vacuum at 70°C for 12 hours, and then grind it for 1 hour; Step 4: Hold at a temperature of 30 min in an oxygen atmosphere, then heat to 500°C at a heating rate of 5°C / min and hold for 3 h. Cool with the furnace and grind for 1 h to obtain near-surface Ti. 4+ NCM811 ternary cathode material with doped layers; Step 5: Transfer 100 mg of the NCM811 ternary cathode material prepared above to the ALD chamber, fix it in the support in the ALD reactor, dry it under vacuum at 70°C for 8 min, and then purge it with argon for 20 s. Step 6: Pulse injection of tetraisopropyl titanate (TTIP) precursor into the chamber for 0.04 s; Step 7: Then purge the chamber with 100 sccm of argon gas; Step 8: Then, the water precursor source is pulsed into the chamber for 0.04 s; Step 9: After settling, purge the chamber with argon gas at 100 sccm to complete one ALD cycle. Then repeat steps 6-8 40 times to obtain a 2 nm TiO2 coating layer. The TEM spectrum of the prepared ternary cathode material is shown below. Figure 1 As shown.

[0026] Example 2 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Add 0.38g of tetrabutyl titanate to 100mL of anhydrous ethanol and stir magnetically for 15min; Step 2: Dissolve 10g of NCM811 ternary cathode material in doped ion precursor solution, ultrasonically disperse for 30min, and let stand for 3h. Step 3: Dry the solution from Step 2 under vacuum at 70°C for 12 hours, and then grind it for 1 hour; Step 4: Hold at a temperature of 30 min in an oxygen atmosphere, then heat to 500 °C at a heating rate of 5 °C / min and hold for 3 h. Cool in the furnace and grind for 1 h to obtain near-surface Ti. 4+ NCM811 ternary cathode material with doped layers.

[0027] Example 3 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Transfer 100mg of undoped NCM811 ternary cathode material to the ALD chamber, fix it in the support in the ALD reactor, dry it under vacuum at 70℃ for 8min, and then purge it with argon for 20s. Step 2: Pulse injection of tetraisopropyl titanate (TTIP) precursor into the chamber for 0.04 s; Step 3: Then purge the chamber with 100 sccm of argon gas; Step 4: Then, the water precursor source is pulsed into the chamber for 0.04 s; Step 5: After standing, purge the chamber with 100 sccm of argon gas to complete one ALD cycle. Then repeat steps 2-4 40 times to obtain a 2 nm TiO2 coating layer.

[0028] Example 4 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Add 0.38g of aluminum nitrate nonahydrate to 100mL of anhydrous ethanol and stir magnetically for 15min; Step 2: Dissolve 10g of NCM811 ternary cathode material in doped ion precursor solution, ultrasonically disperse for 30min, and let stand for 3h. Step 3: Dry the solution from Step 2 under vacuum at 70°C for 12 hours, and then grind it for 1 hour; Step 4: Hold at a temperature of 30 min in an oxygen atmosphere, then heat to 500 °C at a heating rate of 5 °C / min and hold for 3 h. Cool in the furnace and grind for 1 h to obtain near-surface Al. 3+ NCM811 ternary cathode material with doped layers; Step 5: Transfer 100 mg of the NCM811 ternary cathode material prepared above to the ALD chamber, fix it in the support in the ALD reactor, dry it under vacuum at 70°C for 8 min, and then purge it with argon for 20 s. Step 6: Pulse injection of the trimethylaluminum (TMA,Al(CH3)3) precursor source into the chamber for 0.04 s; Step 7: Then purge the chamber with 100 sccm of argon gas; Step 8: Then, the water precursor source is pulsed into the chamber for 0.04 s; Step 9: After standing, purge the chamber with 100 sccm of argon gas to complete one ALD cycle. Then repeat steps 6-8 40 times to obtain a 2 nm Al2O3 coating layer.

[0029] Example 5 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Add 0.38g of aluminum nitrate nonahydrate to 100mL of anhydrous ethanol and stir magnetically for 15min; Step 2: Dissolve 10g of NCM811 ternary cathode material in doped ion precursor solution, ultrasonically disperse for 30min, and let stand for 3h. Step 3: Dry the solution from Step 2 under vacuum at 70°C for 12 hours, and then grind it for 1 hour; Step 4: Hold at a temperature of 30 min in an oxygen atmosphere, then heat to 500 °C at a heating rate of 5 °C / min and hold for 3 h. Cool in the furnace and grind for 1 h to obtain near-surface Al. 3+ NCM811 ternary cathode material with doped layers.

[0030] Example 6 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Transfer 100mg of undoped NCM811 ternary cathode material to the ALD chamber, fix it in the support in the ALD reactor, dry it under vacuum at 70℃ for 8min, and then purge it with argon for 20s. Step 2: Pulse injection of the trimethylaluminum (TMA,Al(CH3)3) precursor source into the chamber for 0.04 s; Step 3: Then purge the chamber with 100 sccm of argon gas; Step 4: Then, the water precursor source is pulsed into the chamber for 0.04 s; Step 5: After standing, purge the chamber with 100 sccm of argon gas to complete one ALD cycle. Then repeat steps 2-4 40 times to obtain a 2 nm Al2O3 coating layer.

[0031] Example 7 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Add 0.38g of zirconium oxychloride to 100mL of anhydrous ethanol and stir magnetically for 15min; Step 2: Dissolve 10g of NCM811 ternary cathode material in doped ion precursor solution, ultrasonically disperse for 30min, and let stand for 3h. Step 3: Dry the solution from Step 2 under vacuum at 70°C for 12 hours, and then grind it for 1 hour; Step 4: Hold at a temperature of 30 min in an oxygen atmosphere, then heat to 500 °C at a heating rate of 5 °C / min and hold for 3 h. Cool in the furnace and grind for 1 h to obtain near-surface Zr. 4+ NCM811 ternary cathode material with doped layers; Step 5: Transfer 100 mg of the NCM811 ternary cathode material prepared above to the ALD chamber, fix it in the support in the ALD reactor, dry it under vacuum at 70°C for 8 min, and then purge it with argon for 20 s. Step 6: Pulse injection of tetrakis(dimethylaminozirconium) (TDMAZ) precursor into the chamber for 0.04 s; Step 7: Then purge the chamber with 100 sccm of argon gas; Step 8: Then, the water precursor source is pulsed into the chamber for 0.04 s; Step 9: After standing, purge the chamber with 100 sccm of argon to complete one ALD cycle. Then repeat steps 6-8 40 times to obtain a 2 nm ZrO2 coating layer.

[0032] Example 8 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Add 0.38g of zirconium oxychloride to 100mL of anhydrous ethanol and stir magnetically for 15min; Step 2: Dissolve 10g of NCM811 ternary cathode material in doped ion precursor solution, ultrasonically disperse for 30min, and let stand for 3h. Step 3: Dry the solution from Step 2 under vacuum at 70°C for 12 hours, and then grind it for 1 hour; Step 4: Hold at a temperature of 30 min in an oxygen atmosphere, then heat to 500 °C at a heating rate of 5 °C / min and hold for 3 h. Cool in the furnace and grind for 1 h to obtain near-surface Zr.4+ NCM811 ternary cathode material with doped layers.

[0033] Example 9 The preparation method of ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition is implemented according to the following steps: Step 1: Transfer 100mg of undoped NCM811 ternary cathode material to the ALD chamber, fix it in the support in the ALD reactor, dry it under vacuum at 70℃ for 8min, and then purge it with argon for 20s. Step 2: Pulse injection of tetrakis(dimethylaminozirconium) (TDMAZ) precursor into the chamber for 0.04 s; Step 3: Then purge the chamber with 100 sccm of argon gas; Step 4: Then, the water precursor source is pulsed into the chamber for 0.04 s; Step 5: After standing, purge the chamber with 100 sccm of argon to complete one ALD cycle. Then repeat steps 2-4 40 times to obtain a 2 nm ZrO2 coating layer.

[0034] Comparative Example The comparative example is the uncoated and undoped commercial ternary cathode material (NCM811).

[0035] Electrode sheets were prepared using the ternary cathode material prepared in Example 1 and the comparative ternary cathode material, respectively. The method was as follows: the ternary cathode material and Super-p were mixed evenly, and then added to an NMP solution of polyvinylidene fluoride and mixed evenly to obtain a cathode slurry; the cathode slurry was coated on the surface of aluminum foil and dried to obtain a ternary cathode sheet. The mass ratio of the conductive agent to the adhesive in the ternary cathode material was 8:1:1. The electrode sheets prepared using the ternary cathode material prepared in Example 1 and the comparative ternary cathode material are respectively designated as cathode sheet 1 and cathode sheet D1.

[0036] The lithium battery is assembled using the aforementioned electrode sheets as positive electrodes, as follows: The electrode sheets were cut into disk shapes (Φ = 12 mm), and the mass loading of the active material was 3-4 mg / cm³. -2 The electrolyte consists of LiPF6 dissolved in ethylene carbonate (EC), dimethyl carbonate (EMC), and diethyl carbonate (DEC), with the addition of 2% vinylene carbonate (VC) and 10% fluoroethylene carbonate (FEC). The separator is Celgard 2325, cut into a disc shape (Φ = 16 mm). Lithium-ion batteries are assembled using lithium wafers as the negative electrode. The lithium-ion batteries assembled with positive electrode 1 and positive electrode D1 are designated as lithium battery 1 and lithium battery D1, respectively.

[0037] The lithium battery 1 containing the ternary cathode material of Example 1 and the lithium battery D1 containing the ternary cathode material of the comparative example were subjected to 300 cycles to test their charge-discharge performance. The test conditions were: temperature 30°C, current density 0.5 A / g, and voltage window from 0.01 V to 1.5 V. The test results are as follows. Figure 2 As shown. From Figure 2 It can be seen that the lithium battery 1 using the ternary cathode material of the present invention achieves a performance of 500 mAg. -1 It can still provide 140mAh g after 300 cycles at a current density. -1 The capacity of the lithium battery D1 is 500 mAg; while the comparative lithium battery D1 has a capacity of 500 mAg. -1 After cycling for 300 cycles at a current density, the capacity decreased to 130 mAh g. -1 .

Claims

1. A method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition, characterized in that, Specifically, the process involves wet impregnation coating to uniformly attach metal ions to the material surface, followed by vacuum drying and solid-state sintering to obtain a near-surface doped cathode material. This material is then transferred to an ALD chamber for coating, thus constructing a cathode material with synergistic regulation between the metal ion doping layer and the metal oxide coating layer.

2. The method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition according to claim 1, characterized in that, The specific steps are as follows: Step 1: Dissolve the metal-doped salt in anhydrous ethanol to prepare a doped ion precursor solution; Step 2: Disperse the NCM811 ternary cathode material in a doped salt ethanol solution and let it stand; Step 3: Vacuum dry the solution, and grind and mix the dried solid. Step 4: High-temperature solid-state sintering and grinding of the powder using a tube furnace; Step 5: Transfer the sintered ternary cathode material to the ALD chamber and fix it in the ALD reactor for vacuum drying, then purge with argon gas. Step 6: Inject the pulse of reaction precursor source 1 into the chamber; Step 7: After settling, purge the chamber with argon gas; Step 8: Inject the pulse of reaction precursor source 2 into the chamber; Step 9: After resting, an ALD cycle is completed with argon purge of the chamber. Several cycles of Step 7-Step 8 are performed to complete different thicknesses of M y O z deposition of cladding layer, where M is Nb, Ti, Al, Zr, Zn, Fe, Mg, Ta, or La.

3. The method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition according to claim 2, characterized in that, In step 1, the metal doped salt includes one of tetrabutyl titanate, aluminum nitrate nonahydrate, or zirconium oxychloride, with an addition amount of 0.2-0.5g, anhydrous ethanol of 50-150mL, and a stirring time of 10-20min.

4. The method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition according to claim 2, characterized in that, In step 2, the amount of NCM811 ternary cathode material is 5-15g, the dispersion time is 20-35min, and the standing time at room temperature is 2-4h.

5. The method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition according to claim 2, characterized in that, In step 3, the vacuum temperature is 60-75℃, the time is 10-12h, and the grinding time is 1-1.5h.

6. The method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition according to claim 2, characterized in that, In step 4, the sintering atmosphere is oxygen, the temperature is 400-500℃, the heating rate is 5℃ / min, and the grinding time is 1-1.5h.

7. The method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition according to claim 2, characterized in that, In step 5, the amount of ternary cathode material taken after sintering is 50-150 mg. The NCM811 ternary cathode material is subjected to ultrasonic cleaning treatment. The transfer process takes 5-10 min, the vacuum temperature is 60-75℃, and the argon purging time is 15-25 s.

8. The method for preparing ternary cathode materials by high-temperature solid-state sintering and atomic layer deposition according to claim 2, characterized in that, In step 6, precursor source 1 contains one of tetraisopropyl titanate, trimethylaluminum or tetradimethylaminozirconium, and the injection time is 0.04-0.06s. In step 8, precursor source 2 is water, and the injection time is 0.04-0.06s.

9. The ternary cathode material prepared by the method of preparing ternary cathode material by high-temperature solid-state sintering and atomic layer deposition according to any one of claims 1-8.

10. A method for preparing a ternary cathode sheet, using the ternary cathode material as described in claim 9, characterized in that, Specifically, the ternary cathode material, conductive agent, and binder in a mass ratio of 8:1:1 are mixed evenly with NMP in a glass bottle to obtain a cathode slurry. The cathode slurry is then coated onto a current collector and dried to obtain a ternary cathode sheet. The current collector is aluminum foil, the conductive agent is Super-P, and the adhesive is polyvinylidene fluoride.

Images