| 摘要 |
PROBLEM TO BE SOLVED: To reduce negative electrode interface polarization during initial charging, facilitate Li insertion into a negative electrode material, and increase an initial discharge capacity by employing a specific polyvinyl ether for a negative electrode binder. SOLUTION: An polyvinyl ether expressed by a general formula (CH2 CH(OR)) n in the range of 50 to 1000 in average polymer degree is employed for a negative electrode binder. Here, R is selected from CH3 , C2 H5 , C4 H9 , and C5 H11 . An additive rate thereof is 6 to 7wt.% of a weight of a negative electrode material. Thereby, reaction of Li and electrolyte can be restricted on a negative electrode surface during initial charging. Thus, when a polyvinyl ether is employed for a negative electrode binder, polarization of a negative electrode interface can be lowered during initial charging. That is, the polyvinyl ether forms a coat on the negantive electrode surface, and Li can be easily inserted into the negative electrode material during initial changing. As a result, reaction probability of Li and electrolyte is lowered, and the initial discharge capacity can be increased. |
