Negative electrode active substance for secondary battery, and secondary battery
View Patent ↗A negative electrode active substance particle according to one embodiment of the present invention, comprises a mother particle that has: a silicate phase that includes Na, Si, and at least one element selected from M, M 1 , M 2 , M 3 and M 4 (M is an alkali earth metal, and M 1 , M 2 , M 3 and M 4 are elements other than alkali metals, alkali earth metals or Si); and silicon particles dispersed in the silicate phase. The contents of the elements in the silicate phase are: 9-52 mol % of Na; 3-50 mol % of M, M 1 , M 2 , M 3 and M 4 ; and at least 25 mol % of Si.
1. A negative electrode active material for a secondary battery comprising:
a silicate phase including elements Na, Si, and M x , wherein M x represents one or more elements other than an alkali metal or Si; and
silicon particles dispersed in the silicate phase, wherein,
the M x includes at least one of elements Y, Nb, V, La, and T
in the silicate phase, the element Na content is 9 mol % to 52 mol %, and the element M x content is 3 mol % to 50 mol %, and a Si content is 25 mol % or more, each based on the total amount other than oxygen, and
the silicon particles have an average particle size of less than 100 nm.
2. The negative electrode active material for a secondary battery according to claim 1 , wherein
the M x further includes at least one of elements Mg, Ca, Ti, Zr, B, Al, and W, and
in the silicate phase, the element Na content is 9 mol % to 52 mol %, the element M x content is 3 mol % to 50 mol %, and the element Si content is 25 mol % or more, each based on the total amount other than oxygen.
3. The negative electrode active material for a secondary battery according to claim 1 , wherein
the element M x includes element Mg in addition to said at least one of elements Y, Nb, V, La, and Ta, and
in the silicate phase, the element Na content is 9 mol % to 52 mol %, an element Mg content is 3 mol % to 12 mol %, a content of said at least one of elements Y, Nb, V, La, and Ta, is 3 mol % to 50 mol %, and the element Si content is 25 mol % or more, each based on the total amount other than oxygen.
4. The negative electrode active material for a secondary battery according to claim 1 , wherein the silicate phase includes less than 5 mol % of the alkali metal other than element Na.
5. A secondary battery comprising:
a negative electrode including the negative electrode active material for a secondary battery according to claim 1 ;
a positive electrode; and an electrolyte.
6. The negative electrode active material for a secondary battery according to claim 1 , wherein
the negative electrode active material comprises a base particle comprising the silicate phase and the silicon particles, and
a content of the silicon particles in the base particle is 20 mass % to 95 mass % based on a total mass of the base particle.
7. The negative electrode active material for a secondary battery according to claim 1 , wherein
the negative electrode active material comprises a base particle comprising the silicate phase and the silicon particles, and
a content of the silicon particles in the base particle is 35 mass % to 75 mass % based on a total mass of the base particle.
8. The negative electrode active material for a secondary battery according to claim 1 , wherein
the negative electrode active material comprises a base particle comprising the silicate phase and the silicon particles, and
a content of the silicate phase is 5 mass % to 80 mass % based on a total mass of the base particle.
9. The negative electrode active material for a secondary battery according to claim 1 , wherein
the negative electrode active material comprises a base particle comprising the silicate phase and the silicon particles, and
a content of the silicate phase is 25 mass % to 65 mass % based on a total mass of the base particle.