Solid electrolyte having magnesium ion conductivity and magnesium secondary battery using the same
A solid electrolyte has a composition represented by the formula: Mg x M y SiO z , where M represents at least one selected from the group consisting of Ti, Zr, Hf, Ca, Sr, and Ba; x satisfies 0<x<2; y satisfies 0<y<2; and z satisfies 3<z<6.
1. A solid electrolyte having a composition represented by a formula:
Mg x M y SiO z , where M represents at least one selected from the group consisting of Zr, Hf, Ca, Sr, and Ba; x satisfies 0<x<2; y satisfies 0<y<2; x and y satisfy 0.5<y/(x+y)<1; z satisfies 3<z<6; being a film having a thickness of 100 nm or more and 20 pm or less.
2. A secondary battery comprising:
a positive electrode containing a positive electrode active material;
a negative electrode containing a negative electrode active material; and
a solid electrolyte having a composition represented by a formula:
Mg x M y SiO z , where M represents at least one selected from the group consisting of Zr, Hf, Ca, Sr, and Ba; x satisfies 0<x<2; y satisfies 0<y<2; x and y satisfy 0.5<y/(x+y)<1; z satisfies 3<z<6.
3. The secondary battery according to claim 2 , wherein M represents at least one selected from the group consisting of Ca, Sr, and Ba.
4. The secondary battery according to claim 2 , wherein M represents Ca.
5. The secondary battery according to claim 2 , being an amorphous material.
6. The secondary battery according to claim 2 , wherein the positive electrode, the solid electrolyte, and the negative electrode are stacked.
7. The secondary battery according to claim 2 , further comprising:
an electrolytic solution filling the space between the positive electrode and the negative electrode and containing a nonaqueous solvent and a magnesium salt dissolved in the nonaqueous solvent, wherein the solid electrolyte covers the positive electrode.
8. The secondary battery according to claim 7 , wherein the positive electrode includes a positive electrode active material layer containing a plurality of positive electrode active material particles; and
the solid electrolyte is disposed as a single layer collectively covering the plurality of the positive electrode active material particles.
9. The secondary battery according to claim 7 , wherein
the Positive electrode includes a positive electrode active material layer containing a plurality of positive electrode active material particles; and
the solid electrolyte is composed of a plurality of coats individually covering the plurality of the positive electrode active material particles.
10. A secondary battery comprising:
a positive electrode containing a positive electrode active material;
a negative electrode containing a negative electrode active material;
a solid electrolyte having a composition represented by a formula: Mg x Zr y SiO z , where; x satisfies 0<x<2; y satisfies 0<y<2; and z satisfies 3<z<6; and
an electrolytic solution filling the space between the positive electrode and the negative electrode and containing a nonaqueous solvent and a magnesium salt dissolved in the nonaqueous solvent,
wherein the solid electrolyte covers the positive electrode.
11. The secondary battery according to claim 10 , being an amorphous material.
12. The secondary battery according to claim 10 , being a film having a thickness of 100 nm or more and 20 pm or less.
13. The secondary battery according to claim 10 , wherein the positive electrode includes a positive electrode active material layer containing a plurality of positive electrode active material particles; and the solid electrolyte is composed of a plurality of coats individually covering the plurality of the positive electrode active material particles.