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KR-102962224-B1 - Lithium-rich manganese oxide as a positive electrode active material for lithium-ion rechargeable batteries

KR102962224B1KR 102962224 B1KR102962224 B1KR 102962224B1KR-102962224-B1

Abstract

The present invention relates to a lithium manganese-based oxide cathode active material comprising an Al outer layer for a lithium-ion secondary battery (LIB) suitable for application in electric vehicles (EVs) and hybrid electric vehicles (HEVs).

Inventors

  • 폴센 옌스 마틴
  • 응우옌 홍남
  • 베첼라니 미카엘
  • 람부 카상드르

Assignees

  • 유미코아
  • 상뜨르 나쇼날 드 라 러쉐르쉬 샹띠피끄
  • 유니베르시테 드 몽펠리에
  • 에꼴 나쇼날 쉬페리에르 드 시미에 드 몽펠리에

Dates

Publication Date
20260508
Application Date
20230303
Priority Date
20220303

Claims (15)

  1. As a positive electrode active material for a lithium-ion rechargeable battery, the positive electrode active material comprises Li, M' and oxygen, and M' is - Mn with a content z such that 40.0 ≤ z ≤ 90.0 mol% for M'; - Ni with a content x such that 0.0 ≤ x ≤ 40.0 mol% for M'; - Co with content y such that 0.0 ≤ y ≤ 10.0 mol% for M'; - M" of content b such that 0.002 ≤ b ≤ 10.0 mol% with respect to M'; - D having a content c such that 0.0 ≤ c ≤ 2.0 mol% with respect to M', comprising elements other than Li, O, Ni, Co, Mn, and M". Includes, and here - x, y, z, b, and c are measured by ICP-OES, and - x+y+z+b+c is 100.0 mole%, and The positive active material has a specific surface area of 3.5 to 9.5 m² /g, and The positive active material comprises secondary particles including primary particles, and the primary particles comprise an outer layer including M", wherein M" is Al, Zr, or a combination thereof.
  2. A positive active material according to claim 1, wherein the atomic ratio of Li to M' (Li/M') is 0.5 to 2.5.
  3. In paragraph 1 or 2, M" is a positive active material that is Al.
  4. In paragraph 3, the Al content Al A A positive electrode active material defined as having an Al content Al B , wherein Al B is determined by XPS analysis and is expressed as a mole fraction compared to the sum of the mole fractions of Ni, Mn, Co, and Al measured by XPS analysis , and a positive electrode active material having a ratio Al B / Al A > 1.
  5. A positive active material according to claim 1 or 2, wherein D comprises at least one element of the group consisting of Zr, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W and Zn.
  6. A positive active material according to claim 1 or 2, wherein the thickness of the outer layer is 0.1 nm to 10.0 nm.
  7. A positive active material according to claim 1 or 2, wherein the Mn content z is greater than 50.0 mol% with respect to M'.
  8. A positive active material according to claim 1 or 2, wherein the Co content y is less than 9.0 mol% with respect to M'.
  9. A positive active material according to claim 1 or 2, wherein the Al content b is greater than 0.6 mol% with respect to M'.
  10. A method for manufacturing a positive electrode active material, comprising the following consecutive steps: Step 1) A step of providing a mixture by uniformly mixing a manganese-based transition metal carbonate with a lithium source; Step 2) a step of calcining the mixture from Step 1) at a temperature of 750℃ to 900℃ to provide a primary calcined material; Step 3) a step of providing a double-fired material by firing the primary fired material from Step 2) at a temperature of 650°C to 750°C; and Step 4) A step of obtaining an anode active material by treating the double-calcined material from Step 3) by an atomic layer deposition reaction with an Al source or a Zr source. A method for manufacturing a positive electrode active material comprising
  11. A manufacturing method according to claim 10, wherein the manganese-based transition metal carbonate of step 1) is first provided in the roasting step.
  12. A manufacturing method according to claim 10 or 11, wherein the positive active material is according to claim 1 or 2.
  13. A battery comprising a positive active material according to paragraph 1 or 2.
  14. In paragraph 13, a battery that is a lithium-ion rechargeable battery.
  15. In paragraph 13, a battery used in any one of a portable computer, tablet, mobile phone, energy storage system, electric vehicle, or hybrid electric vehicle.

Description

Lithium-rich manganese oxide as a positive electrode active material for lithium-ion rechargeable batteries The present invention relates to a lithium manganese-based oxide cathode active material for a lithium-ion secondary battery (LIB) suitable for application in electric vehicles (EVs) and hybrid electric vehicles (HEVs), a method for manufacturing the cathode active material, a battery comprising the cathode active material, and an application of the battery. With the rapid development of small and lightweight electronic products, electronic devices, and communication devices, and the growing need for electric vehicles in relation to environmental issues, there is a demand for performance improvements in secondary batteries used as power sources for these products. Lithium and manganese-rich oxides are attractive in terms of safety and energy density. However, these lithium and manganese-rich oxides must be charged to over 4.5 V to reach a high discharge capacity of approximately 250 mAh/g. This high operating potential (>4.5 V) poses serious problems for the long-term stability of these cathodes due to undesirable reactions with the electrolyte and the dissolution of transition metals at the electrode-electrolyte interface. As a result, the cycle performance of the cathode material is reduced. Therefore, there is a need to further increase the cycle life of the cathode material by mitigating the reaction between these cathodes and the electrolyte through the modification of the surface of these cathodes. The object of the present invention is to provide a positive electrode active material having one or more enhanced characteristics, such as an increase in cycle life, indicated by a capacity degradation rate (QF) value in an electrochemical cell. Another objective of the present invention is to provide a method for manufacturing the above-mentioned positive active material. Another objective of the present invention is to provide a battery comprising the positive electrode active material. Another objective of the present invention is to provide a use for the battery. The above objective is to provide a positive electrode active material for a lithium-ion rechargeable battery comprising Li, M' and oxygen, wherein M' is - Mn with a content z such that 40.0 ≤ z ≤ 90.0 mol% for M'; - Ni with a content x such that 0.0 ≤ x ≤ 40.0 mol% for M'; - Co with content y such that 0.0 ≤ y ≤ 10.0 mol% for M'; - M" of content b such that 0.002 ≤ b ≤ 10.0 mol% with respect to M'; - D having a content c such that 0.0 ≤ c ≤ 2.0 mol% with respect to M', comprising elements other than Li, O, Ni, Co, Mn, and M". Includes, and here - x, y, z, b, and c are measured by ICP-OES, and - x+y+z+b+c is 100.0 mole%, and This is achieved by providing a positive electrode active material comprising a secondary particle containing a primary particle, wherein the primary particle comprises an outer layer containing M", and M" is Al, Zr, or a combination thereof. The inventors have surprisingly discovered that a positive electrode active material produced by atomic layer deposition of Al₂O₃ and/or ZrO₂ , preferably Al₂O₃ , on a Li-rich Mn-based oxide material has an increased cycle life, indicated by a capacity degradation rate (QF) value, as demonstrated in the attached examples. A positive electrode comprising the positive electrode active material of the present invention exhibits improved electrochemical stability compared to a positive electrode comprising a conventional manganese-based oxide due to an aluminum layer on the top of the primary particles. While not wishing to be bound by any theory, the inventors believe that the cycle life of the positive electrode active material is increased by preventing direct contact with the electrolyte through coating the surface of the positive electrode active material. Another aspect of the present invention provides a method for manufacturing an anode active material comprising successive steps of a mixing step, a first calcination step and a drying step, a second calcination step and an aluminum treatment step. Another objective of the present invention is to provide a battery comprising the positive electrode active material. Another objective of the present invention is to provide a use for the battery. Figure 1 shows the Al distribution of EX2 measured by STEM-EDX. Figure 2 shows the thickness of the Al layer of EX2 measured by TEM. Figure 3 shows the XPS profiles of the Al 2p peaks of EX2 and EX3. In the drawings and the following detailed description, preferred embodiments are described in detail to enable the practice of the present invention. Although the present invention has been described with reference to these specific preferred embodiments, it will be understood that the present invention is not limited to these preferred embodiments. Conversely, the present invention includes a number of alternatives, modifications, and equivalents, as will become apparent from the following