Lithium silicate-based compound and production process for the same, positive-electrode active material and positive electrode for use in lithium-ion secondary battery as well as secondary battery

摘要

A lithium silicate-based compound according to the present invention is expressed by a general formula, Li(2−a+b)AaMn(1−x−y)CoxMySiO(4+α)Clβ (In the formula: “A” is at least one element selected from the group consisting of Na, K, Rb and Cs; “M” is at least one member selected from the group consisting of Mg, Ca, Al, Ni, Fe, Nb, Ti, Cr, Cu, Zn, Zr, V, Mo and W; and the respective subscripts appear to be as follows: 0≦“a”<0.2; 0≦“b”<1; 0<“x”<1; 0≦“y”≦0.5; −0.25≦“α”≦1.25; and 0≦“β”≦0.05). The lithium silicate-based compound is used as a positive-electrode active material for secondary battery whose discharge average voltage is higher, and which is able to sorb and desorb lithium ions.

主权项

1. A lithium silicate-based compound being characterized in that:
the lithium silicate-based compound is expressed by a general formula, Li(2−a+b)AaMn(1−x−y)CoxMySiO(4+α) Clβ, wherein “A” is at least one element selected from the group consisting of Na, K, Rb and Cs; “M” is at least one member selected from the group consisting of Mg, Ca, Al, Ni, Fe, Nb, Ti, Cr, Cu, Zn, Zr, V, Mo and W; 0≦“a”<0.2; 0≦“b”<1; 0<“x”<1; 0≦“y”≦0.5; 1-“x”-“y”>0; −0.25≦“α”≦1.25; and 0<“β”<0.05.