To prevent characteristic degradation form being generated afterwards, even when temperature becomes temporarily high by including material produc ing water or carbon dioxide through temperature rise inside a battery.
Interface reaction between electrode active material and an electrolyte caused by temperature rise at the time of charging is impeded by water produced from contained material, so as to suppress degradation of active material. Carbon dioxide produced in temperature rise hinders contact between the active material and electrolyte for suppressing the progress of reaction at an interface. It is preferable that material producing water be one or more kinds of a hydroxide of Zn or the like, a hydroxide oxide of Fe or the like, or a compound containing boric acid or crystal water, contained at a specified ratio in a positive electrode, a negative electrode or the electrolyte so as to produce water at 60-300°C, and it is preferable that material producing carbon dioxide at the time of temperature rise be a carbonate of Rb or the like, or a hydrogen carbonate salt of Na or the like contained at a specified ratio in the positive electrode, the negative electrode, a nonaqueous electrolyte or a separator to produce carbon dioxide at 80-300°C.
MIFUJI YASUHIKO
ITO SHUJI
TOYOGUCHI YOSHINORI
SATO TOSHITADA
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