摘要 |
A powder material which can electrochemically store and release lithium ions rapidly in a large amount is provided. In addition, an electrode structure for an energy storage device which can provide a high energy density and a high power density and has a long life, and an energy storage device using the electrode structure are provided. In a powder material which can electrochemically store and release lithium ions, the surface of particles of one of silicon metal and tin metal and an alloy of any thereof is coated by an oxide including a transition metal element selected from the group consisting of W, Ti, Mo, Nb, and V as a main component. The electrode structure includes the powder material. The battery device includes a negative electrode having the electrode structure, a lithium ion conductor, and a positive electrode, and utilizes an oxidation reaction of lithium and a reduction reaction of lithium ion. |