| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an additive for a sodium ion secondary battery, and to provide a sodium ion secondary battery using the same. <P>SOLUTION: The additive for a sodium ion secondary battery consists of a saturation cyclic carbonate having a fluoro group, or a chain carbonate having a fluoro group. The sodium ion secondary battery includes a nonaqueous electrolyte containing an additive and a nonaqueous solvent, a positive electrode, and a negative electrode. The additive consists of a saturation cyclic carbonate having a fluoro group, or a chain carbonate having a fluoro group. The nonaqueous solvent consists of a nonaqueous solvent that consists of a saturation cyclic carbonate (excepting a nonaqueous solvent consisting only of ethylene carbonate) or consists of a saturation cyclic carbonate and a chain carbonate. The negative electrode has a coat composed of a composite material containing carbon, oxygen, fluorine and sodium in the surface, and contains a negative electrode active material composed of hard carbon. <P>COPYRIGHT: (C)2013,JPO&INPIT |
