Olivine composite cathode material, preparation method and application thereof, and lithium-ion battery

A lithium-ion battery, comprising an olivine composite cathode material, the olivine composite cathode material comprising:

• a matrix;
• and
• a composite phase;
• wherein the matrix has a composition represented by formula I:
• LixM1yMnzFe1-z-uM2u(PO4)w (ROa)bCv formula I, where:
• 0.5≤x<1.3, 0≤y≤0.5, 0<z≤1, 0≤u≤0.01, 0<w≤1, 0<v≤0.05, 0≤a≤8, 0≤b≤1, and 0.3≤1-z-u≤0.4;
• M1 is selected from at least one element of Mg, Na, and K;
• M2 is selected from at least one element of Ga, Sn, V, Y, Mo, Al, Mg, Ce, Ti, Zr, Nb, Si, W, and In;
• and
• R is selected from at least one element of Si, Cl, Br, S, Sb, and Sn;
• and
• wherein the composite phase has a composition represented by formula II:
• TmGn formula II, where:
• 0.1≤m≤5, and 0.1≤n≤5;
• T is selected from at least one element of Ti, Mo, Co, W, Zn, Cu, B, V, Nb, Ta, Pd, Cr, Ag, Al, Mn, Sn, Mg, Sc, Zr, and Hf;
• and
• G is selected from N, or N and C.