| abstract |
Provided is a negative-electrode active material for electricity storage devices that has a low operating potential, can increase the operating voltages of the electricity storage devices, and has excellent cycle characteristics. The negative-electrode active material for electricity storage devices, the negative-electrode active material containing a crystalline phase represented by a general formula Rx1R′x2MAyOz (where R represents at least one selected from Li, Na, and K, R′ represents at least one selected from Mg, Ca, Sr, Ba, and Zn, M represents at least one selected from Ti, V, and Nb, A represents at least one selected from P, Si, B, and Al, 0≤x1≤6, 0≤x2≤6, 0<y≤12, and 0.2≤z≤87, but a case where x1=0.5 and x2=0 and a case where x1=1.5 and x2=0 are excluded). |