Negative electrode active material for electricity storage devices

Abstract

Provided is a negative electrode active material for electricity storage devices, which has low operating potential and is capable of increasing the operating voltage of an electricity storage device,while having excellent cycle characteristics. A negative electrode active material for electricity storage devices, which is characterized by containing a crystal phase represented by general formulaRx1R'x2MAyOz (wherein R represents at least one element selected from among Li, Na and K; R' represents at least one element selected from among Mg, Ca, Sr, Ba and Zn; M represents at least one element selected from among Ti, V and Nb; A represents at least one element selected from among P, Si, B and Al; and 0 <= x1 <= 6, 0 <= x2 <= 6, 0 < y <= 12 and 0.2 <= z <= 87, excluding the cases where x1= 0.5 and x2 = 0 and the cases where x1 = 1.5 and x2 = 0).

Description

technical field [0001] The invention relates to a negative electrode active material used in electrical storage devices such as lithium ion secondary batteries, sodium ion secondary batteries, and hybrid capacitors used in portable electronic equipment, electric vehicles, electric tools, and backup emergency power supplies. Background technique [0002] In recent years, along with the popularization of portable electronic devices and electric vehicles, etc., the development of electric storage devices such as lithium-ion secondary batteries and sodium-ion secondary batteries has been promoted. Materials containing Si or Sn with high theoretical capacity are being studied as negative electrode active materials used in electricity storage devices. However, in the case of using a negative electrode active material containing Si or Sn, the volume change caused by the expansion and contraction of the negative electrode active material that occurs during the intercalation and dein...

AI Technical Summary

Problems solved by technology

However, in the case of using a negative electrode active material containing Si or Sn, the volume change caused by the expansion and contraction of the negative electrode active material that occurs during the intercalation and deintercalation reactions of lithium ions and sodium ions is large, so there is a problem with repeated charge and discharge. However, the collapse of the active material of the negative electrode is severe, and it is easy to cause the problem of degradation of cycle characteristics.

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