Search

KR-20260068109-A - Anode active material and method for manufacturing anode active material

KR20260068109AKR 20260068109 AKR20260068109 AKR 20260068109AKR-20260068109-A

Abstract

The present invention relates to a positive electrode active material comprising at least one metal selected from the group consisting of lithium, oxygen, nickel, manganese, and cobalt, wherein the positive electrode active material comprises Ni, Ni, Mn, and Co with a content of x' such that 40.0 ≤ x' ≤ 98.0 mol% with respect to the sum of Ni, Mn, and Co, Mn with a content of y' such that 0.0 ≤ y' ≤ 30.0 mol% with respect to the sum of Ni, Mn, and Co, and Co with a content of z' such that 0.0 ≤ z' ≤ 30.0 mol% with respect to the sum of Ni, Mn, and Co. The positive electrode active material has an abundant amount of silicon and boron within a surface layer. The positive electrode active material has electrochemical performance for a battery, such as a first discharge capacity and cycling efficiency.

Inventors

  • 구마쿠라 신이치
  • 강 지훈
  • 박 경서

Assignees

  • 유미코아

Dates

Publication Date
20260513
Application Date
20240910
Priority Date
20230911

Claims (17)

  1. A positive electrode active material for a battery comprises at least one metal selected from the group consisting of lithium, oxygen, nickel, manganese, and cobalt, and a. For the sum of Ni, Mn, and Co, Ni with a content x' such that 40.0 ≤ x' ≤ 98.0 mol%, b. For the sum of Ni, Mn, and Co, Mn with a content y' such that 0.0 ≤ y' ≤ 30.0 mol%, c. For the sum of Ni, Mn and Co, it contains Co with a content z' such that 0.0 ≤ z' ≤ 30.0 mol%, and x', y' and z' are measured by ICP-OES, and The above-mentioned cathode active material further comprises boron having a content B B , wherein B B is expressed as the mole fraction of B relative to the total amount of Ni, Mn, Co, Si and B measured by XPS analysis, and B B > 0.30 and, The above positive active material further comprises silicon, and The above-mentioned positive active material is a positive active material that exhibits a peak of a binding energy level of 101.4 eV to 106.0 eV when measured by XPS analysis.
  2. The anode active material according to claim 1, wherein the anode active material exhibits a peak of a binding energy level of 101.4 eV to 105.0 eV, preferably 101.5 eV to 104.5 eV, more preferably 101.6 eV to 104.0 eV when measured by XPS analysis.
  3. In claim 1 or 2, the anode active material has a content of Si B , and Si B is expressed as the mole fraction of Si relative to the total amounts of Ni, Mn, Co, Si, and B measured by XPS analysis, and Anode active material with Si B > 0.01.
  4. A positively active material according to claim 3, wherein Si B is in the range of 0.03 to 1.0, preferably Si B is in the range of 0.05 to 0.3, and more preferably Si B is in the range of 0.08 to 0.2.
  5. A positively active material according to any one of claims 1 to 4, wherein BB is in the range of 0.35 to 5.0, preferably BB is in the range of 0.4 to 2.0, and more preferably BB is in the range of 0.68 to 1.0.
  6. In any one of paragraphs 1 to 5, comprising Li, M' and oxygen, and M' is a. For M', Ni with content x such that 50.0 ≤ x ≤ 98.0 mol%, b. For M', Mn with content y such that 0.0 ≤ y ≤ 30.0 mol%, c. For M', Co with content z such that 0.0 ≤ z ≤ 30.0 mol%, For d. M', Si with content a such that 0.0 < a ≤ 5.0 mol%, e. For M', B with content b such that 0.0 < b ≤ 5.0 mol%, f. For M', it contains D with a content d such that 0.0 ≤ d ≤ 2.0 mol%, where D is an element different from Li, Ni, Mn, Co, Si, B, and oxygen, and x, y, z, a, b, and d are measured by ICP-OES, and x + y + z + a + b + d is a positively active material of 100.0 mol%.
  7. A positive active material according to any one of claims 1 to 6, wherein the positive active material has a Si content Si A defined as a/(x + y + z + a + b), wherein the ratio Si B / Si A is > 30.0.
  8. A positive active material according to any one of claims 1 to 7, wherein the positive active material has a B content B A defined as b/(x + y + z + a + b), wherein the ratio B B / B A is > 30.0.
  9. In any one of paragraphs 6 through 8, a. Ni with respect to M', having a content x such that 75.0 mol% ≤ x ≤ 92.0 mol%, preferably 78.0 mol% ≤ x ≤ 90.0 mol%, more preferably 80.0 mol% ≤ x ≤ 88.0 mol%, b. Mn having a content y such that, with respect to M', 0.0 mol% < y ≤ 20.0 mol%, preferably 1.0 mol% ≤ y ≤ 15.0 mol%, more preferably 2.0 mol% ≤ y ≤ 10.0 mol%, c. Co with a content z such that, with respect to M', 0.0 mol% < z ≤ 20.0 mol%, preferably 1.0 mol% ≤ z ≤ 15.0 mol%, more preferably 2.0 mol% ≤ z ≤ 10.0 mol%, d. Si having an content a such that, with respect to M', 0.01 mol% < a ≤ 2.0 mol%, preferably 0.03 mol% ≤ a ≤ 1.0 mol%, more preferably 0.06 mol% ≤ a ≤ 0.1 mol%, e. With respect to M', B having an content of b such that 0.01 mol% < b ≤ 4.0 mol%, preferably 0.1 mol% ≤ b ≤ 3.0 mol%, more preferably 0.4 mol% ≤ b ≤ 2.0 mol%, f. A positively active material comprising a content D of which, with respect to M', 0.0 mol% < d ≤ 1.75 mol%, preferably 0.25 mol% ≤ d ≤ 1.5 mol%, more preferably 0.5 mol% ≤ d ≤ 1.25 mol%.
  10. An anode active material according to any one of claims 1 to 9, wherein the anode active material is a powder comprising single particles and/or secondary particles, and when observed in an SEM image, each of the single particles consists of only one primary particle, and each of the secondary particles consists of at least two primary particles to a maximum of 20 primary particles.
  11. A positively active material according to claim 10, wherein at least 30%, more preferably at least 50%, of the particles constituting the powder are single particles and/or secondary particles when observed in an SEM image.
  12. An anode active material according to any one of claims 1 to 10, wherein the anode active material is a powder comprising polycrystalline particles, and each of the polycrystalline particles consists of more than 20 primary particles when observed in an SEM image.
  13. An anode active material according to any one of claims 1 to 12, wherein the anode active material has a carbon absorption of less than 340% carbon based on the total weight of the anode active material, preferably less than 245% carbon based on the total weight of the anode active material, more preferably less than 200% carbon, and said carbon absorption is measured by an exposure test.
  14. A method for manufacturing a positively active material, preferably a positively active material described in any one of claims 1 to 13, wherein Step a) of mixing a lithium transition metal-based oxide compound with a silicon source and a boron source, and The method comprises step b) of obtaining an anode active material by heating the mixture at a temperature of less than 500℃ for 1 to 20 hours, and A method for preparing an anode active material, wherein the silicon (Si) source is a Si-alkoxide, an alkylalkoxysilane, or a polysiloxane, preferably a polysiloxane, more preferably a hydroxy-terminated polysiloxane.
  15. A method for preparing an anode active material according to claim 14, wherein the boron source is boric acid ( H₃BO₃ ), boron oxide ( B₂O₃ ), sodium tetrahydroxyborate (NaB( OH ) ₄ ), trisodium orthoborate (Na₃BO₃ ) , sodium perborate ( Na₂H₄B₂O₅ ) , sodium metaborate ( Na₃B₃O₆ ) , or a combination thereof, preferably wherein the boron source is boric acid ( H₃BO₃ ).
  16. A solid-state battery comprising a positively active material described in any one of claims 1 to 13.
  17. A solid-state battery comprising a sulfide-based solid electrolyte in Clause 16.

Description

Anode active material and method for manufacturing anode active material The present invention relates to a positive electrode active material comprising lithium, oxygen, nickel, boron, and silicon, and having a surface rich in silicon and boron in particular. The present invention also relates to a method for manufacturing a positive electrode active material comprising lithium, oxygen, nickel, boron, and silicon, and having an abundant amount of silicon and boron in a surface layer in particular; a battery comprising said positive electrode active material and an use of said battery. With the rapid advancement of small and lightweight electronic products, electronic devices, and communication devices, and the widespread emergence of the 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. Among these, lithium-ion batteries are attracting attention as high-performance batteries due to their high energy density and high reference electrode potential. During the charging process of a secondary battery, lithium ions exit the cathode, move through the electrolyte, and enter the anode, while electrons exit the cathode and enter the anode through the external circuit (charger). During the use or discharge of the secondary battery, lithium ions exit the anode, move through the electrolyte, and enter the cathode, while electrons flow through the external circuit to provide electrical work. Commonly used cathode active materials are lithium transition metal oxides. During the charging and/or discharging of lithium batteries, delithiated cathode active materials slowly react with non-aqueous electrolytes or solid electrodes, which can consequently progressively degrade the electrochemical performance of lithium batteries using such cathode active materials. The step of applying a surface layer of a metal such as Ti or Zr onto a cathode active material (i.e., applying a thin surface layer of the metal onto the cathode active material to increase or concentrate the amount of said metal within said surface layer) has been proven to produce a cathode active material exhibiting improved electrochemical performance compared to a counterpart without said surface layer. Doo et al. [ACS Appl. Energy Mater. 2019, 2, 6246-6253] disclose a hydrophobic Ni-rich oxide material obtained by mixing polycrystalline LiNi 0.8 Co 0.1 Mn 0.1 with polydimethylsiloxane and then heating at 230°C to improve the electrochemical stability of the Ni-rich oxide material. However, there remains a need to provide anode active materials with improved storage stability and/or improved electrochemical stability. The object of the present invention is to provide a positively active material comprising silicon and boron to improve the storage stability of the positively active material and/or improve the electrochemical performance of the positively active material, in particular the efficiency of the primary discharge capacity and/or reversible capacity. Another objective of the present invention is to provide a method for manufacturing a positively active material comprising silicon and boron. Another objective of the present invention is to provide a battery comprising the above-mentioned positive active material powder. Another objective of the present invention is to provide a use for the battery. In a first embodiment, the object of the present invention is achieved by providing an anode active material comprising at least one metal selected from the group consisting of lithium, oxygen, nickel, manganese, and cobalt, wherein the active material is, a. For the sum of Ni, Mn, and Co, Ni with a content x' such that 40.0 ≤ x' ≤ 98.0 mol%, b. For the sum of Ni, Mn, and Co, Mn with a content y' such that 0.0 ≤ y' ≤ 30.0 mol%, c. With respect to the sum of Ni, Mn, and Co, it comprises Co with an content of z' such that 0.0 ≤ z' ≤ 30.0 mol%, wherein x', y', and z' are measured by ICP-OES, and The above positive active material has an abundant amount of silicon and boron within the surface layer. That is, as understood by those skilled in the art, the anode active material of the present invention has a surface layer containing silicon and boron, in particular a surface layer containing amounts of Si and B higher than the average Si and B within the material. The inventors have surprisingly discovered that the positive active material of the present invention improves the electrochemical performance of batteries, particularly solid-state batteries such as sulfide solid-state batteries, as demonstrated in the examples attached herein. Specifically, the positive active material of the present invention increases the cycling efficiency of the battery and/or improves the primary discharge capacity of the battery. Without being bound by any theory, the inventors have discovered that treating an anode active material with polydimethylsiloxan