| abstract |
The invention relates to the technical field of lithium ion batteries, and specifically discloses a lithium iron silicate positive electrode material with a defect structure, the positive electrode material comprises lithium iron silicate and carbon, and the carbon coats the lithium iron silicate; The lithium iron silicate contains lithium vacancies and excess iron defects, wherein excess iron occupies lithium vacancies, and has a polyanionic silicate lattice structure, and the chemical formula of the lithium iron silicate is [Li 2-x Fe y ] Li [Fe] Fe SiO 4 , the lithium iron silicate is obtained by uniformly mixing compounds containing a lithium source, an iron source and a silicon source in proportion, and then calcining in an inert atmosphere. In the present invention, the precursors containing lithium source, iron source, silicon source and carbon are mixed uniformly in proportion, and then calcined in an inert atmosphere to obtain the defect structure lithium iron silicate material. The material has more iron content, and at the same time, it can suppress the problem of cation mixing during the cycle, so it can have higher charge-discharge capacity and stable cycle performance. |