Ternary positive electrode material and preparation method thereof

Abstract

The application provides a ternary positive electrode material and a preparation method thereof, and belongs to the technical field of lithium ion batteries. The ternary positive electrode material doped with zirconium and aluminum is obtained through a mixed sintering method, CQDs are in-situ grown on the surface of the ternary material through a solvothermal method, and finally, the ternary material coated with the CQDs is coated with a layer of nano CaCO3, so as to obtain a ternary positive electrode material with a doping and coating structure. The ternary positive electrode material prepared by the application has good electronic conductivity, can effectively inhibit the growth of lithium dendrites, and can enhance the structural stability of the material through doping modification, so as to improve the low-temperature power, high-temperature storage and cycle performance of the ternary lithium ion battery.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a ternary cathode material and its preparation method. Background Technology

[0002] Developing new energy vehicles is a powerful measure for my country to seek new economic growth points and promote industrial transformation and upgrading. More importantly, new energy vehicles are in line with the current trend of green travel. Among these factors, the driving range of a vehicle is a crucial factor in its rapid and widespread adoption, which largely depends on the energy density of the cathode material in lithium-ion batteries. In recent years, nickel-cobalt-manganese ternary cathode materials have been favored by many automakers due to their advantages of high capacity and high voltage, becoming a key development focus in the industry. However, nickel-cobalt-manganese ternary materials generally face several problems that urgently need to be addressed. First, while ternary materials have high voltage and energy storage capacity, they are prone to structural evolution during cyclic charging and discharging, leading to rapid capacity degradation. Second, ternary lithium batteries are prone to degradation and failure at high temperatures, and their power performance at low temperatures still needs further optimization. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a high-performance ternary cathode material that exhibits good electronic conductivity and effectively suppresses the growth of lithium dendrites. Furthermore, by doping and modifying the material, its structural stability is enhanced, thereby improving the low-temperature power, high-temperature storage, and cycle performance of ternary lithium-ion batteries.

[0004] The ternary cathode material provided by the present invention includes a zirconium and aluminum doped ternary cathode material located in the inner core, and a CQDs coating layer and a nano CaCO3 coating layer sequentially coating the surface of the zirconium and aluminum doped ternary cathode material from the inside out.

[0005] Zirconium and aluminum are used to bulk dope the ternary material to enhance its structural stability. The CQDs coating layer has excellent conductivity, which can improve the transmission efficiency of electrons and lithium ions, thereby improving the low-temperature power performance of the ternary battery cell. The nano-CaCO3 coating layer can stabilize the crystal structure of the ternary material. At the same time, the nano-CaCO3 can continuously adsorb the by-product HF of the electrolyte, inhibit the acidification of the electrolyte at high temperature, and avoid the growth of lithium dendrites caused by acidity, thereby improving the high-temperature storage and cycle performance of the ternary lithium-ion battery.

[0006] The zirconium and aluminum dual-doped ternary cathode material has the molecular formula LiNi. 0.7 Co 0.1 Mn 0.2 O2;

[0007] The mass of the CQDs coating layer is 0.01%-0.05% of the mass of the zirconium and aluminum doped ternary cathode material, and the mass of the nano-CaCO3 coating layer is 0.05%-0.15% of the mass of the zirconium and aluminum doped ternary cathode material.

[0008] The above-mentioned ternary cathode material is prepared by a method including the following steps:

[0009] 1) Preparation of zirconium and aluminum doped ternary cathode material: The ternary precursor is mixed with lithium carbonate, zirconium source and aluminum source, and then the mixed material is sintered in an oxygen atmosphere. After sintering, it is crushed to obtain zirconium and aluminum doped ternary cathode material.

[0010] 2) Preparation of CQDs coating layer: The zirconium and aluminum doped ternary cathode material obtained in step 1) is mixed with ethylene glycol (CH2OH)2 in a certain mass ratio and stirred continuously. The resulting solution is transferred to a reaction vessel, heated and kept at a certain temperature to obtain a ternary cathode material with CQDs coated on the surface.

[0011] 3) Preparation of nano-CaCO3 coating layer: After uniformly mixing the product obtained in step 2) with nano-CaCO3, the mixture is sintered in an oxygen atmosphere to obtain a ternary cathode material with double doping and double coating structure.

[0012] In step 1) of the above method, the molecular formula of the ternary precursor is: Ni 0.7 Co 0.1 Mn 0.2 (OH)2;

[0013] The zirconium source may be at least one of zirconium oxide and zirconium hydroxide;

[0014] The aluminum source can be at least one of aluminum oxide and oxygen hydroxide.

[0015] The amount of zirconium added is 0.1%-0.3% of the mass of the ternary precursor;

[0016] The amount of aluminum added is 0.05%-0.15% of the mass of the ternary precursor;

[0017] The ratio of the total molar number of metals in the ternary precursor to the molar number of Li in lithium carbonate is 1:1.02-1.069;

[0018] The sintering conditions are 900-930℃ and the time is 10-20h;

[0019] Oxygen with a purity of over 95% is introduced during the sintering process;

[0020] In step 2) of the above method, the mass ratio of ethylene glycol (CH2OH)2 to the zirconium and aluminum doped ternary cathode material obtained in step 1) can be 1:2-6;

[0021] The continuous stirring time can be 1-3 hours;

[0022] The heating temperature can be 160-240℃, and the holding time can be 4-6 hours;

[0023] Step 2) also includes the operation of cooling the reaction system to room temperature after heat preservation, centrifuging, washing, and vacuum drying of the precipitate, wherein the vacuum drying temperature can be 100-120℃ and the time can be 4-8h.

[0024] In step 3) of the above method, the amount of nano-CaCO3 added is 0.05-0.15% of the mass of the ternary cathode material obtained in step 2).

[0025] The sintering temperature is 600-700℃, and the time is 4-6 hours;

[0026] Step 3) also includes operations such as crushing, sieving, and demagnetizing the sintered product to obtain the final product.

[0027] The application of the aforementioned ternary cathode material in lithium-ion batteries also falls within the scope of protection of this invention.

[0028] The present invention also provides a lithium-ion battery, wherein the positive electrode of the lithium-ion battery is made of the above-mentioned ternary positive electrode material.

[0029] The present invention also provides an electrical device comprising the aforementioned lithium-ion battery.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The ternary cathode material with double doping and double coating structure prepared by this invention has excellent low-temperature power performance, as well as good high-temperature storage and cycling performance. Attached Figure Description

[0032] Figure 1 The low-temperature power performance diagrams for the four groups of battery cells are shown.

[0033] Figure 2 The high-temperature storage performance diagram shows the performance of the four battery cells.

[0034] Figure 3 The high-temperature cycling performance diagrams for the four groups of battery cells are shown.

[0035] Figure 4 This is a scanning electron microscope image of the ternary cathode material prepared in Example 4 of the present invention. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0037] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0038] Example 1

[0039] A method for preparing a high-performance ternary cathode material includes the following steps:

[0040] S1. Preparation of zirconium-aluminum dual-doped ternary cathode materials:

[0041] The ternary precursor (Ni) 0.7 Co 0.1 Mn 0.2 (OH)2) is mixed with lithium carbonate, zirconium oxide and aluminum oxide. The molar ratio of the ternary precursor to lithium carbonate (the ratio of the total number of moles of metal in the ternary precursor to the number of moles of Li in the lithium carbonate) is 1:1.04. The amount of zirconium added accounts for 0.2% of the mass of the ternary precursor, and the amount of aluminum added accounts for 0.1% of the mass of the ternary precursor. The mixed material is then sent to a sintering furnace at 915℃ and calcined for 15 hours. Oxygen with a purity of more than 95% is introduced during the sintering process. After sintering, the material is crushed to obtain a zirconium and aluminum doped ternary cathode material.

[0042] S2. Preparation of CQDs coating layer:

[0043] The ternary cathode material prepared by ethylene glycol (CH2OH)2 and S1 was mixed at a mass ratio of 1:2 and stirred continuously for 3 hours. The uniformly mixed solution was transferred to a reaction vessel, heated to 200°C, kept at that temperature for 5 hours, cooled to room temperature, centrifuged and washed, and the precipitate was vacuum dried at 100°C for 6 hours to obtain the ternary cathode material with CQDs coated on the surface.

[0044] S3. Preparation of nano-CaCO3 coating layer:

[0045] After uniformly mixing the product obtained in step S2 with nano-CaCO3, the mixture is calcined in a 700℃ sintering furnace for 5 hours, with oxygen introduced into the furnace during sintering. Finally, the sintered material is crushed, sieved, and demagnetized to obtain the final product, which is a ternary cathode material with a double-doped and double-coated structure. The amount of nano-CaCO3 added accounts for 0.15% of the ternary cathode material obtained in step S2.

[0046] Example 2

[0047] A method for preparing a high-performance ternary cathode material includes the following steps:

[0048] S1. Preparation of zirconium-aluminum dual-doped ternary cathode materials:

[0049] The ternary precursor (Ni) 0.7 Co 0.1 Mn 0.2 (OH)2) is mixed with lithium carbonate, zirconium oxide and aluminum oxide. The molar ratio of the ternary precursor to lithium carbonate (the ratio of the total number of moles of metal in the ternary precursor to the number of moles of Li in lithium carbonate) is 1:1.04. The amount of zirconium added accounts for 0.2% of the mass of the ternary precursor, and the amount of aluminum added accounts for 0.1% of the mass of the ternary precursor. The mixed material is then sent to a sintering furnace at 915℃ and calcined for 15 hours. During the sintering process, oxygen with a purity of more than 95% is introduced. After sintering, the material is crushed to obtain a zirconium and aluminum doped ternary cathode material.

[0050] S2. Preparation of CQDs coating layer:

[0051] The ternary cathode material prepared by ethylene glycol (CH2OH)2 and S1 was mixed at a mass ratio of 1:4 and stirred continuously for 3 hours. The uniformly mixed solution was transferred to a reaction vessel, heated to 200°C, kept at that temperature for 5 hours, cooled to room temperature, centrifuged and washed, and the precipitate was vacuum dried at 100°C for 6 hours to obtain the ternary cathode material with CQDs coated on the surface.

[0052] S3. Preparation of nano-CaCO3 coating layer:

[0053] After uniformly mixing the product obtained in step S2 with nano-CaCO3, the mixture is calcined in a 700℃ sintering furnace for 5 hours, with oxygen introduced into the furnace during sintering. Finally, the sintered material is crushed, sieved, and demagnetized to obtain the final product, which is a ternary cathode material with a double-doped and double-coated structure. The amount of nano-CaCO3 added accounts for 0.15% of the ternary cathode material obtained in step S2.

[0054] Example 3

[0055] A method for preparing a high-performance ternary cathode material includes the following steps:

[0056] S1. Preparation of zirconium-aluminum dual-doped ternary cathode materials:

[0057] The ternary precursor (Ni) 0.7 Co 0.1 Mn 0.2 (OH)2) is mixed with lithium carbonate, zirconium oxide and aluminum oxide. The molar ratio of the ternary precursor to lithium carbonate (the ratio of the total number of moles of metal in the ternary precursor to the number of moles of Li in lithium carbonate) is 1:1.04. The amount of zirconium added accounts for 0.2% of the mass of the ternary precursor, and the amount of aluminum added accounts for 0.1% of the mass of the ternary precursor. The mixed material is then sent to a sintering furnace at 915℃ and calcined for 15 hours. During the sintering process, oxygen with a purity of more than 95% is introduced. After sintering, the material is crushed to obtain a zirconium and aluminum doped ternary cathode material.

[0058] S2. Preparation of CQDs coating layer:

[0059] The ternary cathode material prepared by ethylene glycol (CH2OH)2 and S1 was mixed at a mass ratio of 1:2 and stirred continuously for 3 hours. The uniformly mixed solution was transferred to a reaction vessel, heated to 200°C, kept at that temperature for 5 hours, cooled to room temperature, centrifuged and washed, and the precipitate was vacuum dried at 100°C for 6 hours to obtain the ternary cathode material with CQDs coated on the surface.

[0060] S3. Preparation of nano-CaCO3 coating layer:

[0061] After uniformly mixing the product obtained in step S2 with nano-CaCO3, the mixture is calcined in a sintering furnace at 650℃ for 5 hours, with oxygen introduced into the furnace during sintering. Finally, the sintered material is crushed, sieved, and demagnetized to obtain the final product, which is a ternary cathode material with a double-doped and double-coated structure. The amount of nano-CaCO3 added accounts for 0.15% of the ternary cathode material obtained in step S2.

[0062] Example 4

[0063] A method for preparing a high-performance ternary cathode material includes the following steps:

[0064] S1. Preparation of zirconium-aluminum dual-doped ternary cathode materials:

[0065] The ternary precursor (Ni) 0.7 Co 0.1 Mn 0.2(OH)2) is mixed with lithium carbonate, zirconium oxide and aluminum oxide. The molar ratio of the ternary precursor to lithium carbonate (the ratio of the total number of moles of metal in the ternary precursor to the number of moles of Li in lithium carbonate) is 1:1.04. The amount of zirconium added accounts for 0.2% of the mass of the ternary precursor, and the amount of aluminum added accounts for 0.1% of the mass of the ternary precursor. The mixed material is then sent to a sintering furnace at 915℃ and calcined for 15 hours. During the sintering process, oxygen with a purity of more than 95% is introduced. After sintering, the material is crushed to obtain a zirconium and aluminum doped ternary cathode material.

[0066] S2. Preparation of CQDs coating layer:

[0067] The ternary cathode material prepared by ethylene glycol (CH2OH)2 and S1 was mixed at a mass ratio of 1:2 and stirred continuously for 3 hours. The uniformly mixed solution was transferred to a reaction vessel, heated to 200°C, kept at that temperature for 5 hours, cooled to room temperature, centrifuged and washed, and the precipitate was vacuum dried at 100°C for 6 hours to obtain the ternary cathode material with CQDs coated on the surface.

[0068] S3. Preparation of nano-CaCO3 coating layer:

[0069] After uniformly mixing the product obtained in step S2 with nano-CaCO3, the mixture is calcined in a sintering furnace at 650℃ for 5 hours, with oxygen introduced into the furnace during sintering. Finally, the sintered material is crushed, sieved, and demagnetized to obtain the final product, which is a ternary cathode material with a double-doped and double-coated structure. The amount of nano-CaCO3 added accounts for 0.1% of the ternary cathode material obtained in step S2.

[0070] Figure 4 The image shows a scanning electron microscope (SEM) image of the prepared ternary cathode material.

[0071] Using undoped ternary cathode material as sample A0 (the ternary precursor (Ni) is used as the substrate), the ternary cathode material is used as the substrate. 0.7 Co 0.1 Mn 0.2 (OH)2) is mixed with lithium carbonate, and the molar ratio of the ternary precursor to lithium carbonate (the ratio of the total number of moles of metal in the ternary precursor to the number of moles of Li in the lithium carbonate) is 1:1.04; then the mixed material is sent to a sintering furnace at 915℃ for calcination for 15 hours, during which oxygen with a purity of more than 95% is introduced. After sintering, it is crushed to obtain ternary cathode material. The ternary cathode material that has been doped but not coated is used as sample A1 (the ternary precursor (Ni)2) is mixed with lithium carbonate. 0.7 Co 0.1 Mn 0.2(OH)2) was mixed with lithium carbonate, zirconium oxide, and aluminum oxide. The molar ratio of the ternary precursor to lithium carbonate (the ratio of the total number of moles of metal in the ternary precursor to the number of moles of Li in lithium carbonate) was 1:1.04. The amount of zirconium added accounted for 0.2% of the mass of the ternary precursor, and the amount of aluminum added accounted for 0.1% of the mass of the ternary precursor. The mixed material was then calcined in a 915℃ sintering furnace for 15 hours. Oxygen with a purity of over 95% was introduced during the sintering process. After sintering, the material was crushed to obtain a zirconium and aluminum double-doped ternary cathode material. The ternary cathode material with double doping and single coating of CQDs was used as sample A2 (the ternary precursor (Ni) 0.7 Co 0.1 Mn 0.2 (OH)2) was mixed with lithium carbonate, zirconium oxide, and aluminum oxide. The molar ratio of the ternary precursor to lithium carbonate (the ratio of the total number of moles of metal in the ternary precursor to the number of moles of Li in lithium carbonate) was 1:1.04. The amount of zirconium added accounted for 0.2% of the mass of the ternary precursor, and the amount of aluminum added accounted for 0.1% of the mass of the ternary precursor. The mixed material was then calcined in a 915℃ sintering furnace for 15 hours, during which oxygen with a purity of over 95% was introduced. After sintering, the material was crushed to obtain a zirconium and aluminum doped ternary cathode material. Ethylene glycol (CH2OH)2 was mixed with the obtained ternary cathode material at a mass ratio of 1:2 and stirred continuously for 3 hours. The uniformly mixed solution was transferred to a reaction vessel, heated to 200℃, held for 5 hours, cooled to room temperature, centrifuged, washed, and the precipitate was collected. The ternary cathode material with CQDs coated on the surface was obtained by vacuum drying at 100℃ for 6 hours. Using the ternary cathode material with double doping and double coating structure prepared in Example 4 as sample A3, corresponding ternary lithium-ion batteries were prepared using samples A0, A1, A2, and A3 respectively under the same active material ratio. The cathode was prepared by mixing NCM:CNTs:PVDF=98:1:1, the double-sided surface density of the cathode coating was 331.6 g / m2, and the compaction of the cathode roller was 3.5 g / cc. The anode was prepared by mixing graphite:SP:CMC:SBR=96.2:0.8:1.2:1.8, the double-sided surface density of the anode coating was 216 g / m2, and the compaction of the anode roller was 1.6 g / cc. The Xinzhoubang E8A high-voltage electrolyte and Enjie 9+2+2+1+1 type separator were used. The four lithium-ion battery packs are identical in all aspects except for the cathode material, including the materials used, quantities, and manufacturing methods. The following are the test results for the performance of the four battery cells:

[0072] (1) Low-temperature power performance test of battery

[0073] The specific testing method is as follows: Four sets of battery cells were charged at 25℃ from 2.8V to 4.35V at a constant current of 0.33C, and then charged at a constant voltage of 4.35V with a cutoff current of 0.05C. Then, they were discharged at 0.33C to 2.8V, and this cycle was repeated three times. The average discharge capacity over the three cycles was taken as the cell capacity C0. Based on the C0 value, the cells were adjusted to 20% SOC at 25℃, and then placed at -25℃ for 10 hours, followed by a 30-second discharge at 1.1C. The test results are shown in Table 1. Figure 1 .

[0074] Table 1. Low-temperature DCR performance of four groups of battery cells at -25℃

[0075]

[0076] From Table 1 and Figure 1 It can be seen that dual-doping modification can reduce the low-temperature DCR of ternary materials. Introducing a CQDs coating layer on top of dual doping can significantly reduce the low-temperature DCR of ternary materials. After coating with nano-CaCO3, the low-temperature DCR performance of the ternary materials remains unchanged. This demonstrates that applying the dual-doped and dual-coated ternary cathode material prepared in this invention to lithium-ion batteries greatly improves the low-temperature power performance of the battery. (The lower the low-temperature DCR value of the cell, the better its low-temperature power performance.)

[0077] (2) Battery high-temperature storage performance test

[0078] The specific testing method is as follows: Four sets of battery cells were charged at 25℃ from 2.8V to 4.35V at a constant current of 1C, and then charged at a constant voltage of 4.35V with a cutoff current of 0.05C. Then, they were discharged at a constant current of 1C to 2.8V, and this cycle was repeated for three weeks. The average discharge capacity over the three weeks was taken as the initial capacity C0 of the battery cell. After fully charging the cells at 1C, they were placed in a 60℃ constant temperature chamber for 7 days, and then subjected to three charge-discharge cycles at 25℃. The test results are shown in Table 2 and [Table data would be inserted here]. Figure 2 .

[0079] Table 2. High-capacity retention and recovery rate (mean) of four groups of battery cells.

[0080]

[0081] From Table 2 and Figure 2 It can be seen that dual-doping modification and single-coating CQDs can slightly improve the high-temperature storage performance of ternary materials. On this basis, the high-temperature storage performance of ternary materials is significantly improved after introducing a nano-CaCO3 coating layer. This shows that when the dual-doped and dual-coating ternary cathode material prepared in this invention is applied to lithium-ion batteries, the high-temperature storage performance of the battery is greatly improved.

[0082] (3) Battery high-temperature cycle performance test

[0083] The specific testing method is as follows: Four sets of battery cells were charged from 2.8V to 4.35V at a constant current of 0.5C, and then charged at a constant voltage of 4.35V with a cutoff current of 0.05C; then discharged to 2.8V at a constant current of 1C. This process was repeated for 2000 cycles. The test results are shown in Table 3. Figure 3 As shown.

[0084] From Table 3 and Figure 3 It can be seen that after 380 cycles, the capacity retention of sample A0 has dropped to about 87%. After double doping modification, the cycle performance of the ternary material can be slightly improved, and after 546 cycles, the capacity retention is about 85.7%. Introducing a CQDs coating layer on the basis of double doping can significantly improve the high cycle performance of the material, and the high cycle life of the cell is about 860 cycles. After coating with nano-CaCO3, the high cycle performance of the ternary material is further improved, and after 937 cycles, the capacity retention is still above 80%. This shows that when the double-doped and double-coated ternary cathode material prepared in this invention is applied to lithium-ion batteries, the high-temperature cycle performance of the battery is also significantly improved.

[0085] Table 3 High-Temperature Cyclic Capacity Retention Rate of Four Groups of Cells

[0086]

[0087] In summary, the ternary cathode material with double doping and double coating structure prepared by this invention has excellent low-temperature power performance, as well as good high-temperature storage and cycling performance.

[0088] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. A ternary cathode material, characterized in that, The ternary cathode material includes a zirconium and aluminum doped ternary cathode material located in the inner core, and a CQDs coating layer and a nano CaCO3 coating layer that are sequentially coated on the surface of the zirconium and aluminum doped ternary cathode material from the inside out. The mass of the CQDs coating layer is 0.01%-0.05% of the mass of the zirconium and aluminum doped ternary cathode material, and the mass of the nano-CaCO3 coating layer is 0.05%-0.15% of the mass of the zirconium and aluminum doped ternary cathode material. The method for preparing the ternary cathode material includes the following steps: 1) Preparation of zirconium and aluminum doped ternary cathode material: The ternary precursor is mixed with lithium carbonate, zirconium source and aluminum source, and then the mixed material is sintered in an oxygen atmosphere. After sintering, it is crushed to obtain zirconium and aluminum doped ternary cathode material. 2) Preparation of CQDs coating layer: The zirconium and aluminum doped ternary cathode material obtained in step 1) is mixed with ethylene glycol (CH2OH)2 and stirred continuously. The resulting solution is transferred to a reaction vessel, heated and kept at a certain temperature to obtain a ternary cathode material with CQDs coated on the surface. 3) Preparation of nano-CaCO3 coating layer: After uniformly mixing the product obtained in step 2) with nano-CaCO3, the mixture is sintered in an oxygen atmosphere to obtain a ternary cathode material with double doping and double coating structure.

2. The ternary cathode material according to claim 1, characterized in that, In step 1) of the method, the molecular formula of the ternary precursor is: Ni 0.7 Co 0.1 Mn 0.2 (OH)2; The amount of zirconium added is 0.1%-0.3% of the mass of the ternary precursor; The amount of aluminum added is 0.05%-0.15% of the mass of the ternary precursor; The ratio of the total number of moles of metal in the ternary precursor to the number of moles of Li in lithium carbonate is 1:1.02-1.

069.

3. The ternary cathode material according to claim 1, characterized in that, In step 1) of the method, the sintering conditions are 900-930℃ and the time is 10-20h; Oxygen with a purity of over 95% is introduced during the sintering process.

4. The ternary cathode material according to claim 1, characterized in that, In step 2) of the method, the mass ratio of ethylene glycol (CH2OH)2 to the zirconium and aluminum doped ternary cathode material obtained in step 1) is 1:2-6. The continuous stirring time is 1-3 hours; The heating temperature is 160-240℃, and the holding time is 4-6 hours; Step 2) also includes the operation of cooling the reaction system to room temperature after heat preservation, centrifuging, washing, and vacuum drying of the precipitate, wherein the vacuum drying temperature is 100-120℃ and the time is 4-8h.

5. The ternary cathode material according to claim 1, characterized in that, In step 3) of the method, the amount of nano-CaCO3 added is 0.05-0.15% of the mass of the ternary cathode material obtained in step 2). The sintering temperature is 600-700℃, and the time is 4-6 hours; Step 3) also includes operations such as crushing, sieving, and demagnetizing the sintered product to obtain the final product.

6. The application of the ternary cathode material according to any one of claims 1-5 in lithium-ion batteries.

7. A lithium-ion battery, wherein the positive electrode of the lithium-ion battery is made of the ternary positive electrode material according to any one of claims 1-5.

8. An electrical device comprising the lithium-ion battery of claim 7.

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