| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a battery capable of obtaining improved cycle characteristics. <P>SOLUTION: The negative electrode active substance of a negative electrode active substance layer 2 contains: a negative electrode active substance particle 2A having silicon as a constituting element; and a covering film 2B that contains silicon and oxygen as constituting elements and covers at least a portion of the surface of the negative electrode active substance particle 2A. A negative electrode binder contains polyimide, and the content of polyimide in the negative electrode active substance layer 2 is within a range of not less than 5 wt.% and not more than 30 wt.%. High energy density can be obtained, and the decomposition reaction of an electrolyte is suppressed even if the negative electrode active substance particle 1A occludes an electrode reactive substance, such as lithium, and is alloyed. The affinity between the negative electrode active substance and the negative electrode binder is improved and sufficient adhesion properties are obtained between the negative electrode active substances, thus reducing the content of the negative electrode binder causing electrical resistance and restraining the electric resistance of the negative electrode active substance layer 2B. <P>COPYRIGHT: (C)2008,JPO&INPIT |
