Active material and battery
A main object of the present disclosure is to provide a novel active material whose volume variation due to charge/discharge is small. The present disclosure achieves the object by providing an active material having a composition represented by Na x M y Si 46 , wherein M is a metal element other than Na, x and y satisfy 0<x, 0≤y, y≤x and 0<x+y<8, and comprising a crystal phase of a Type I silicon clathrate.
1. An active material having a composition represented by Na x M y Si 46 , wherein M is a metal element other than Na, x and y satisfy 0<x,0≤y,y≤x and 0<x+y<8, and
comprising a crystal phase of a Type I silicon clathrate.
2. The active material according to claim 1 , wherein the active material comprises the crystal phase of the Type I silicon clathrate as a main phase.
3. The active material according to claim 1 , wherein the crystal phase of the Type I silicon clathrate has a peak at a position of 2θ=30.33°±1.00°, 31.60°±1.00°, 32.82°±1.00°, 52.39°±1.00° and 55.49°±1.00° in X-ray diffraction measurement using a CuKα ray.
4. The active material according to claim 1 , wherein the active material does not comprise a Si crystal phase of a diamond-type,
the Si crystal phase of the diamond-type has a peak at a position of 2θ=28.44°±1.00° in X-ray diffraction measurement using a CuKα ray, and
when a diffraction intensity of the peak at 2θ=32.82°±1.00° is regarded as I A , and a diffraction intensity of the peak at 2θ=28.44°±1.00° is regarded as I B , I B /I A is more than 0, and 0.1 or less.
5. The active material according to claim 3 , wherein the active material comprises a Si crystal phase of a diamond-type,
the Si crystal phase of the diamond-type has a peak at a position of 2θ=28.44°±1.00° in X-ray diffraction measurement using a CuKα ray, and
when a diffraction intensity of the peak at 2θ=32.82°±1.00° is regarded as I A , and a diffraction intensity of the peak at 2θ=28.44°±1.00° is regarded as I B , I B /I A is more than 0, and 0.1 or less.
6. The active material according to claim 1 , wherein the x and the y satisfy 2.9≤x,2.9≤x+y≤7.1.
7. A battery comprising a cathode layer, an electrolyte layer, and an anode layer, in this order, and
the anode layer includes the active material according to claim 1 .
8. The battery according to claim 7 , wherein the electrolyte layer includes an inorganic solid electrolyte.
9. The battery according to claim 7 , wherein the electrolyte layer includes a liquid electrolyte.
10. The battery according to claim 7 , wherein the battery is a lithium ion battery.
11. The battery according to claim 7 , wherein the battery is a sodium ion battery.