| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative electrode and a battery optimizing the specific surface area of a negative electrode material capable of storing/desorbing lithium, and improving a property. SOLUTION: A wound electrode element 20 wherein a strip-shaped positive electrode 21 and a negative electrode 22 are wound through a separator 23 is provided. The separator 23 is impregnated with an electrolytic solution. The negative electrode 22 includes the negative electrode material capable of storing/ desorbing lithium, and on the negative electrode 22, lithium metal is deposited halfway through charging. Namely, the capacity of the negative electrode 22 is expressed by the sum of capacitive component due to storing/desorbing of lithium and capacitive component due to depositing/fusing of lithium metal. The specific surface area of the negative electrode material capable of storing/ desorbing lithium is not more than 5.0 m<2> /g. Therefore, a contact area between the negative electrode material and the electrolytic solution can be made to have a suitable size, and abrupt deterioration in energy density can be suppressed. |
