| abstract |
An active material containing silicon as a main component, in which generation of silicon oxide is suppressed, and a high-capacity and long-life electrode structure and an electricity storage device are provided. A primary particle of 10 nm to 300 nm composed mainly of silicon aggregates to form a secondary particle, and a surface layer of the primary particle is selected from at least Al, Zr, Mg, Ca, La. A negative electrode active material for an electricity storage device capable of electrochemically inserting and desorbing lithium ions, comprising a composite oxide layer formed at least from one or more metal elements and Li, and a method for producing the same. An electrode structure comprising the above active material and exfoliated graphite, and an electricity storage device using the electrode structure as a negative electrode. [Selection] Figure 1 |