Preparation methods of lithium ion battery composite positive electrode, flexible lithium battery and solid-state lithium battery

Abstract

The invention relates to preparation methods of a lithium ion battery composite positive electrode, a flexible lithium battery and a solid-state lithium battery. A composite positive electrode material of which a surface is coated with an inorganic rapid lithium ion conductor is obtained by uniformly mixing a precursor liquid of the rapid lithium ion conductor and a lithium ion battery positive electrode material under a certain temperature, and an inorganic rapid lithium ion conductor coated composite positive electrode material is obtained after thermal processing is performed on the composite positive electrode, wherein the inorganic rapid lithium ion conductor is a high-electrical conductivity garnet-shaped solid-state electrolyte Li<5+x>N<x>La<3-x>M<2>O<12> (X is more than or equal to 0 but less than or equal to 2, M is Nb, Ta, Sb or Bi, and N is Ca, Ba, Sr or Ge) and a modified compound thereof Li<7+x>(La<2-x>M<x>)B<2>O<12> (X is more than or equal to 0 but less than or equal to 2, M is Ca, Ba, Sr or Ge, and B is Zr, Hf or Sn), or Li<7-x>La<3>Zr<2-x>Ta<x>O<12> (X is more than or equal to 0 but less than or equal to 2); and / or the inorganic rapid lithium ion conductor is LiM<2>O<4> with a spinel structure, and M is Ni and / or Mn; and / or the inorganic rapid lithium ion conductor is LiMO<2> with a layered structure, and M is at least one of Ni, Co, Mn and Al; and / or the inorganic rapid lithium ion conductor is a lithium-rich manganese-based positive electrode material (x)Li<2>MnO<3>.(1-x)LiMO<2>, x is more than 0.1 but less than 0.9, and M is one of Ni, Co and Mn. By the composite positive electrode material, the cycle performance, the high-temperature performance and the rate performance of the lithium ion battery positive electrode material can be improved.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and relates to positive electrode materials of lithium ion batteries, specifically lithium ion battery positive electrode materials coated with inorganic fast lithium ion conductors and a preparation method thereof, and lithium ion batteries coated with the inorganic fast lithium ion conductors Application of positive electrode materials in lithium-ion batteries and lithium metal all-solid-state batteries. Background technique [0002] The current lithium-ion battery cathode materials, especially high-voltage cathode materials, such as lithium cobalt oxide, spinel lithium manganese oxide, etc., still have some key problems to be solved urgently, except for the first large irreversible capacity, poor rate performance, In addition to the common problems such as severe cycle capacity fading, when high-voltage cathode materials are used in solid-state batteries, a series of problems will also ari...

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Problems solved by technology

Some studies have used metal oxides to coat and modify positive electrode materials (patent 105932251A 201610389932.9), but the lithium-conducting activity of the coating layer is low, which is not conducive to the transmission of lithium ions between electrode materials. This problem is solved in all-solid lithium It will become more serious in the battery

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