Amorphous oxide-based positive electrode active material, method for producing same and use of same

1. An amorphous oxide-based positive electrode active material being a production material of a positive electrode for an all-solid secondary battery, comprising an alkali metal selected from Li and Na; a second metal selected from Co, Ni, Mn, Fe, Cr, V, Cu, Ti, Zn, Zr, Nb, Mo, Ru and Sn; an ionic species selected from phosphate ion, sulfate ion, borate ion, silicate ion, aluminate ion, germanate ion, nitrate ion, carbonate ion and halide ion; and an oxygen atom, except for the oxygen atom not constituting the ionic species,

wherein said amorphous oxide-based positive electrode active material exhibits such an amorphous state that all the 2θ peaks observed in an XRD pattern have half-value widths of 0.5 or more.

2. The amorphous oxide-based positive electrode active material according to claim 1 , wherein the amorphous oxide-based positive electrode active material is a production material of a positive electrode for an all-solid secondary battery, and wherein:

the amorphous oxide-based positive electrode active material

(i) comprises an alkali metal selected from Li and Na; a second metal selected from Co, Ni, Mn, Fe, Cr, V, Cu, Ti, Zn, Zr, Nb, Mo, Ru and Sn; an ionic species selected from phosphate ion, sulfate ion, borate ion, silicate ion, aluminate ion, germanate ion, nitrate ion, carbonate ion and halide ion; and an oxygen atom, not constituting the ionic species;

(ii) contains at least an amorphous phase; and

(iii) a production material of a positive electrode with a thickness of 20 μm or more.

3. The amorphous oxide-based positive electrode active material according to claim 1 , which comprises an alkali metal selected from Li and Na; a second metal selected from Co, Ni, Mn, Fe, Cr, V, Cu, Ti, Zn, Zr, Nb, Mo, Ru and Sn; an ionic species selected from phosphate ion, sulfate ion, borate ion, silicate ion, aluminate ion, germanate ion, nitrate ion, carbonate ion and halide ion; and an oxygen atom, not constituting the ionic species; is in an amorphous state; and is a production material of a positive electrode with a thickness of 20 μm or more for an all-solid secondary battery.

4. The amorphous oxide-based positive electrode active material according to claim 1 , comprising an amorphous phase and a crystalline phase.

5. The amorphous oxide-based positive electrode active material according to claim 1 , comprising components derived from an alkali metal oxide and an alkali metal salt, wherein the alkali metal oxide is selected from the group consisting of lithium-based compounds of LiCoO 2 , LiNiO 2 , LiMnO 2 , Li 2 MnO 3 , Li(Ni, Co, Mn)O 2 , Li 2 TiO 3 , LiFeO 2 , LiCrO 2 , Li 2 CuO 2 , LiCuO 2 , LiMoO 2 , Li 2 RuO 3 , Li 3 NbO 4 , Li 3 V 2 (PO 4 ) 3 , LiMn 2 O 4 and Li(Ni, Mn)O 4 and sodium-based compounds of NaCoO 2 , NaNiO 2 , NaMnO 2 , Na 2 MnO 3 , Na(Ni, Co, Mn)O 2 , NaFeO 2 , Na 2 TiO 3 , NaCrO 2 , Na 2 CuO 2 , NaCuO 2 , NaMoO 2 , Na 2 RuO 3 , Na 3 NbO 4 , Na 3 V 2 (PO 4 ) 3 , NaMn 2 O 4 and Na(Ni, Mn)O 4 , and the alkali metal salt is selected from

AxByOz, wherein A is Li or Na; B is selected from P, S, B, C, Si, Al, Ge and N; x is 1 or more; y is 1 or more; z is 1 or more; and x, y and z are stoichiometrically possible values, and

AX, wherein A is Li or Na; and X is selected from F, Cl, Br and I.

6. The amorphous oxide-based positive electrode active material according to claim 5 , wherein the component derived from the alkali metal oxide and the component derived from the alkali metal salt exist in the amorphous oxide-based positive electrode active material at a molar ratio of 1:9 to 9:1.

7. The amorphous oxide-based positive electrode active material according to claim 1 , comprising components derived from LiCoO 2 and Li 3 PO 4 and/or Li 2 SO 4 .

8. A positive electrode with a thickness of 20 μm or more, comprising the amorphous oxide-based positive electrode active material according to claim 1 .

9. An all-solid secondary battery comprising at least the positive electrode according to claim 8 , a negative electrode and a solid electrolyte layer positioned between the positive electrode and the negative electrode.

10. A method for producing the amorphous oxide-based positive electrode active material according to claim 1 , wherein the amorphous oxide-based positive electrode active material is obtained by mixing raw materials thereof by mechanical milling.