Negative electrode active material for power storage device

Abstract

The present invention provides a negative electrode active material for a power storage device, wherein the negative electrode active material has a low operating potential, can have an increased operating voltage for a power storage device, and has excellent cycle characteristics. This negative electrode active material for a power storage device is characterized by containing, by mol% in terms of oxide, 1-95% of TiO2 and 5-75% of P2O5+SiO2+B2O3+Al2O3+R'O (R' represents at least one selected from among Mg, Ca, Sr, Ba and Zn), and also containing 10 mass% or more of amorphous phases.

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 emergency power supplies. Background technique [0002] In recent years, along with the popularization of portable electronic devices and electric vehicles, etc., the development of power storage devices such as lithium-ion secondary batteries and sodium-ion secondary batteries has been promoted. Materials containing Si or Sn having a 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 generated during the intercalation and deintercalat...

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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 generated 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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