To prevent battery characteristics to be deteriorated even if the bat tery is left in a high-temperature atmosphere for a long time by adding LiF to a carbonic material used as a negative electrode active material.
By adding LiF to a carbonaceous material of a negative electrode active material, the generation of an electrolyte reduction decomposition product is suppressed so that battery characteristics after high-temperature storage can be improved. The additional quantity is 1-10%, and more preferably, when it is 2-5%, the LiF is made present not only on the surface of a negative electrode plate but also in its inside so that its function acting on an electrolyte reduction decomposition reaction as a negative catalyst is fully exerted. In addition, in the case of a secondary battery using any one of LiPFs, LiClO4, LiBF4 and LiAlCl4 for a nonaqueous electrolyte, and using LiMxN1-xO2 (M and N each is one or more of Co, Mn, Cr, Fe, V and Al in the condition of 1≥x≥0.5) for a positive electrode active material, its effect is particularly significant.
WATANABE SHOICHIRO
MURAOKA NORIKI
KOBAYASHI SHIGEO
| JPH07235297A | 1995-09-05 | |||
| JPH07302617A | 1995-11-14 |
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