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KR-102961733-B1 - Cathode material and method of manufacturing the same, lithium-ion battery

KR102961733B1KR 102961733 B1KR102961733 B1KR 102961733B1KR-102961733-B1

Abstract

The present invention relates to the technical field of lithium-ion batteries and discloses a cathode material, a method for manufacturing the same, and a lithium-ion battery. The composition of the cathode material is Li 1+a (Ni x Co y Mn z G b )T c O 2 ; 0.02≤a≤0.1, 0.6≤x≤1, 0<y≤0.5, 0<z≤0.5, 0<b≤0.02, 0<c≤0.02; and the characteristic (003) peak at around 80 cycles at 45° satisfies 0°≤△P=P before -P after ≤0.2°. The cathode material has high grain strength and superior crystalline structural stability, and the cycle performance of the cathode material is significantly improved.

Inventors

  • 진, 위치앙
  • 통, 쥔판
  • 왕, 루이
  • 장, 쉬에취엔
  • 리우, 야페이
  • 천, 옌빈

Assignees

  • 베이징 이스프링 머티리얼 테크놀로지 컴퍼니 리미티드

Dates

Publication Date
20260507
Application Date
20240329
Priority Date
20240304

Claims (20)

  1. As a cathode material, the cathode material has a composition expressed by the following formula I, and [Food I] Li 1+a (Ni x Co y Mn z G b )T c O 2 In the above Equation I, 0.02≤a≤0.1, 0.6≤x≤1, 0<y≤0.5, 0<z≤0.5, 0<b≤0.02, 0<c≤0.02; G is at least one selected from Al, Y, Zr, Ti, Ca, V, Nb, Ta, Co, W, Er, La, Sb, Mg, Sr, Sn, Mn, Mo, Ce, F, B, and P; T is at least one selected from Al, Sr, Si, Nb, Co, W, Ti, Zr, Ce, Mn, F, B, and P; Here, the characteristic peak of (003) at around 80 cycles at 45°C measured by XRD satisfies the relationship 0°≤△P= P_before -P_after ≤0.2°, where P_before is the peak position of the characteristic peak of (003) before the cycle, and P_after is the peak position of the characteristic peak of (003) after 80 cycles; A cathode material characterized by having a median particle size of 4 to 18 μm.
  2. In paragraph 1, 0.03≤a≤0.07, 0.6≤x≤1, 0<y≤0.5, 0<z≤0.5, 0.005≤b≤0.015, 0.002≤c≤0.015 and; and/or, G is at least one selected from Al, Ti, Co, Sr, Ce, F, Y, Zr, W and La; and T is at least one selected from B, Al, Si, W and F; and/or, a cathode material having 0°≤△P≤0.1°.
  3. In paragraph 1, The lattice volume V of the cathode material at 0% SOC, 50% SOC, and 100% SOC measured by XRD is Satisfying the relationship 0%≤△V 50% =(V 50 -V 0 )/V 0 ≤10%, and/or, 0%≤△V 100% =(V 100 -V 0 )/V 0 ≤15%, Here, V0 is the lattice volume of the cathode material at 0% SOC; V50 is the lattice volume of the cathode material at 50% SOC; and V100 is the lattice volume of the cathode material at 100% SOC.
  4. In paragraph 1, The specific surface area SSA of the above-mentioned cathode material before and after pressure satisfies the relationship 0% ≤ △SSA% = (SSA 4 - SSA 0 ) / SSA 0 ≤ 80%, where SSA 0 is the specific surface area of the cathode material before pressure and SSA 4 is the specific surface area of the cathode material after applying a pressure of 4.5 tons.
  5. In paragraph 4, Cathode material with 0%≤△SSA%≤50%.
  6. In paragraph 1, A cathode material having a residual alkali content of 0 to 10,000 ppm.
  7. In paragraph 6, A cathode material having a residual alkali content of 1,000 to 8,000 ppm.
  8. A method for manufacturing a cathode material according to any one of claims 1 to 7, wherein the manufacturing method is A step (1) of physically mixing a precursor, a lithium source, and an additive optionally containing a C1 element to obtain a homogeneous mixture I; Step (2) of first sintering mixture I under an oxygen-containing atmosphere, setting the isothermal temperature to T1 and the isothermal time to t1 , and obtaining first sintered material II by crushing and sieving or direct sieving after sintering; A step (3) of mixing primary sintered material II with an additive, optionally containing a C2 element, to obtain a uniform mixture III; Step (4) of secondarily sintering mixture III under an oxygen-containing atmosphere, setting the isothermal temperature to T2 and the isothermal time to t2 , and obtaining second sintered material IV by crushing and sieving or direct sieving after sintering; A step (5) of obtaining a uniform mixture V by mixing a secondary sintered material IV and an additive containing element T; and The method includes the step (6) of sintering mixture V a third time under an oxygen-containing atmosphere, setting the isothermal temperature to T3 and the isothermal time to t3 , and obtaining the anode material by crushing and sieving or direct sieving after sintering. Here, the precursor is selected from nickel-cobalt-manganese oxide and/or nickel-cobalt-manganese hydroxide; and the amounts of the lithium source, the precursor, the additive containing the C1 element, and the additive containing the C2 element are such that in the cathode material, n(Li):[n(Ni)+n(Co)+n(Mn)+n(G)]=1.02~1.10:1; A manufacturing method characterized by adding at least one of an additive containing a C1 element and an additive containing a C2 element.
  9. In paragraph 8, A manufacturing method in which the ratio of the lithium source, the precursor, the additive containing the C1 element, and the additive containing the C2 element is such that n(Li):[n(Ni)+n(Co)+n(Mn)+n(G)]=1.03~1.07:1.
  10. In paragraph 8, A manufacturing method in which the amounts of the above precursor, the additive containing the C1 element, and the additive containing the C2 element used in the cathode material are such that 0 < n(G): [n(Ni)+n(Co)+n(Mn)+n(G)] ≤ 0.02.
  11. In Paragraph 10, A manufacturing method in which the amounts of the above precursor, the additive containing the C1 element, and the additive containing the C2 element used in the cathode material are such that 0.005≤n(G):[n(Ni)+n(Co)+n(Mn)+n(G)]≤0.015.
  12. In paragraph 8, A manufacturing method in which the amount of the above secondary sintered material and the additive containing the above T element used is such that in the cathode material, 0 < n(T): [n(Ni)+n(Co)+n(Mn)+n(G)] ≤ 0.02.
  13. In Paragraph 12, A manufacturing method in which the amount of the above secondary sintered material and the additive containing the above T element used is such that in the cathode material, 0.002≤n(T):[n(Ni)+n(Co)+n(Mn)+n(G)]≤0.015.
  14. In paragraph 8, C1 and C2 are each independently at least one selected from Al, Y, Zr, Ti, Ca, V, Nb, Ta, Co, W, Er, La, Sb, Mg, Sr, Sn, Mn, Mo, Ce, F, B, and P; and/or, a manufacturing method in which T is at least one selected from Al, Sr, Si, Nb, Co, W, Ti, Zr, Ce, Mn, F, B and P.
  15. In Paragraph 14, A manufacturing method in which T is at least one selected from B, Al, Si, W and F.
  16. In Paragraph 14, C1 is a manufacturing method in which at least one is selected from Al, Y, Zr, W, La, Sr, and Ce.
  17. In Paragraph 14, C2 is a manufacturing method in which at least one is selected from Al, Ti, Co, Sr, Ce, and F.
  18. In paragraph 8, A manufacturing method in which constant temperatures T1 , T2 , and T3 satisfy the relationship 200℃ ≤T3 ＜ T2 ＜ T1≤1000 ℃.
  19. In Paragraph 18, A manufacturing method in which 200℃≤T3 ≤500 ℃.
  20. In Paragraph 18, A manufacturing method in which 400℃≤T 2 ≤900℃.

Description

Cathode material and method of manufacturing the same, lithium-ion battery The present invention claims priority and rights to patent application No. 202410244850.X filed with the Chinese Intellectual Property Administration on March 4, 2024, the contents of which are incorporated herein by reference in their entirety. The present invention relates to the technical field of lithium-ion batteries, and more specifically, the present invention relates to a cathode material, a method for manufacturing the same, and a lithium-ion battery. In recent years, with the development of the global new energy vehicle industry, lithium-ion batteries have attracted the attention of many people due to their high energy density and excellent cycle performance. Ternary materials are widely used due to their advantages, such as high energy density and excellent low-temperature performance, and high nickel content and high voltage have become the two main directions of current development to pursue even higher energy density. However, whether it is high nickel content or high voltage, the current challenges are mainly that the structural stability of the material is poor after high nickel content or high voltage, which further leads to poor cycle stability of ternary materials and increased gas generation. Regarding the challenge of structural stability, the current primary means of improvement is to use means such as internal structural adjustment of the material, body phase doping, and surface coating. For example, CN108598379A discloses a nickel-cobalt-aluminum oxide lithium composite material coated with lithium tungstate, as well as a method for manufacturing the same and its application. Specifically, a nickel-cobalt-aluminum precursor is dispersed in a lithium-containing solution, and then tungsten trioxide is added . The lithium-containing solution reacts with the tungsten trioxide to produce Li₂WO₄ , and during the evaporative crystallization process , Li₂WO₄ is directly deposited and coated onto the nickel-cobalt-aluminum precursor. Then, by performing sintering of the lithium mixture, LiNi₄ 0.8 Co₄ 0.15 Al₄ 0.05 O₂ @ Li₂WO₄ can be obtained . Through the deposited coating formed by this in-situ reaction, a very uniform coating layer can be formed. The cathode material produced by this method exhibits good doping and coating effects, but the process is complex, the liquid recovery process is complicated, and the cost is high. The above and/or additional aspects and advantages of the present invention will become clear and easily understood from the description of the embodiments with reference to the drawings below. Figure 1 is a diagram of the 003 peak position measured by an XRD diffractometer before and after the cycle of the cathode material of Example 1. Figure 2 is a diagram of the 003 peak position measured by an XRD diffractometer before and after the cycle of the cathode material of Comparative Example 1. Figure 3 is a cross-sectional EDS analysis diagram of the cathode material of Example 4. Figure 4 is a comparison of the cycle performance of lithium-ion batteries obtained by assembling the cathode materials of Example 1 and Comparative Example 1. All endpoints and any values of the ranges disclosed herein are not limited to these exact ranges or values, and should be understood to include values close to these ranges or values. With respect to numerical ranges, the endpoint values of each range, the endpoint values of each range and individual point values, and the individual point values may be combined with one another to obtain one or more new numerical ranges, and such numerical ranges should be considered as specifically disclosed herein. A first aspect of the present invention provides a cathode material, wherein the cathode material has a composition represented by the following formula I, and [Food I] Li 1+a (Ni x Co y Mn z G b )T c O 2 In the above Equation I, 0.02≤a≤0.1, 0.6≤x≤1, 0<y≤0.5, 0<z≤0.5, 0<b≤0.02, 0<c≤0.02; G is at least one selected from Al, Y, Zr, Ti, Ca, V, Nb, Ta, Co, W, Er, La, Sb, Mg, Sr, Sn, Mn, Mo, Ce, F, B, and P; T is at least one selected from Al, Sr, Si, Nb, Co, W, Ti, Zr, Ce, Mn, F, B, and P; Here, the characteristic peak (003) at 45°C at around 80 cycles measured by XRD satisfies the relationship 0°≤△P=P before -P after ≤0.2°, where P before is the peak position of the characteristic peak (003) at around 80 cycles, and P after is the peak position of the characteristic peak (003) at around 80 cycles. In the present invention, the change in peak position of the characteristic peak (003) after 80 cycles at 45°C is relatively small, which indicates that the cathode material has high particle strength and superior crystal structural stability, which is advantageous for Li ion transport and cycle performance, and in particular, the cathode material contains an appropriate Li content, which ensures high discharge capacity and high capacity retention rate when used in a lithium-io