Cathode material and manufacturing method thereof, lithium ion battery, and vehicle
AssigneeBYD Company Limited
InventorsDongjie Hu, Hao Wei
Life of this patent
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Abstract
A cathode material, a preparation method thereof, a lithium ion battery and a vehicle are provided. The cathode material comprises elemental sulfur and secondary particles formed by packing primary particles, wherein the secondary particles have a hollow structure, and the elemental sulfur fills in gaps among the primary particles and in the hollow structure. The primary particles comprise a lithium oxide, wherein the lithium oxide comprises δLiNimConX(1-m-n)O2:(1−δ)Li2MO3, 0≤δ≤1, X comprises at least one selected from Mn, Al, Nb, and Fe, M comprises at least one of Mn, Al, Nb, Fe, Co, and Ni, 0≤m<1, 0≤n<1, and 0≤m+n<1.
Claims20
A cathode material, comprising elemental sulfur and secondary particles, wherein
- each of the secondary particles is formed by packing primary particles and has a hollow structure and gaps among the primary particles, a coating is formed on an outer surface of each of the secondary particles, and the coating comprises titanium dioxide,
- the elemental sulfur fills in the gaps among the primary particles and in the hollow structure of each of the secondary particles, wherein a content of elemental sulfur in the hollow structure is higher than a content of elemental sulfur in the gaps among the primary particles, and
- the primary particles comprise a lithium oxide, wherein the primary particles are selected from at least one of rod-shaped lithium oxide and bulk lithium oxide, the primary particles have a length of 0.5-2 μm, a width of 200-500 nm, and an aspect ratio of 2-40, a weight ratio of the lithium oxide, the elemental sulfur of the cathode material, and the titanium dioxide is (90-45):(5-50):(2-8), the lithium oxide comprises δLiNimConX(1-m-n)O2·(1−δ)Li2MO3, X comprises at least one selected from Mn, Al, Nb, and Fe, M comprises at least one of Mn, Al, Nb, Fe, Co, and Ni, 0<δ≤1, 0≤m<1, 0≤n<1, and 0<m+n<1.
A method for preparing a cathode material, comprising:
- stirring and adding a solution containing metal ions, a complexing agent, and a precipitating agent to a reactor, co-precipitating at a pH of 11-12 to form a primary particle precursor, forming a core precursor by packing the primary particle precursor, and forming a secondary particle precursor by further packing the primary particle precursor at a pH of 9-10.5;
- mixing the secondary particle precursor with a lithium source, and baking to obtain secondary particles having a hollow structure;
- and
- mixing the secondary particles with a sulfur source, melting and solidifying, to fill elemental sulfur into the hollow structure, wherein
- the secondary particles have a shell layer for defining the hollow structure, and the shell layer is formed by packing the primary particles, and
- the primary particles comprise lithium oxide comprising δLiNimConX(1-m-n)O2:(1−δ)Li2MO3, in which, X comprises at least one selected from Mn, Al, Nb, and Fe, M comprises at least one selected from Mn, Al, Nb, Fe, Co, and Ni, 0<δ≤1, 0<m<1, 0≤n<1, and 0<m+n<1;
- wherein the solution containing metal ions comprises one or more of a solution containing Mn ions, a solution containing Al ions, a solution containing Nb ions, a solution containing Fe ions, a solution containing Co ions, and a solution containing Ni ions;
- the complexing agent comprises aqueous ammonia;
- and
- the precipitating agent comprises one or two of potassium hydroxide and sodium hydroxide.
A lithium ion battery, comprising a cathode material comprising elemental sulfur and secondary particles, wherein
- each of the secondary particles is formed by packing primary particles and has a hollow structure and gaps among the primary particles, a coating is formed on an outer surface of each of the secondary particles, and the coating comprises titanium dioxide,
- the elemental sulfur is filled in the gaps among the primary particles and in the hollow structure of each of the secondary particles, wherein a content of elemental sulfur in the hollow structure is higher than a content of elemental sulfur in the gaps among the primary particles, and
- the primary particles comprise a lithium oxide, wherein the primary particles are selected from at least one of rod-shaped lithium oxide and bulk lithium oxide, the primary particles have a length of 0.5-2 μm, a width of 200-500 nm, and an aspect ratio of 2-40, a weight ratio of the lithium oxide, the elemental sulfur of the cathode material, and the titanium dioxide is (90-45):(5-50):(2-8), the lithium oxide comprises δLiNimConX(1-m-n)O2·(1−δ)Li2MO3, X comprises at least one selected from Mn, Al, Nb, and Fe, M comprises at least one of Mn, Al, Nb, Fe, Co, and Ni, Fe, Co, and Ni, 0<δ≤1, 0<m<1, 0≤n<1, and 0<m+n<1.
Dependencies are inferred from the claim text.