An electrolyte whose battery capacity, cycle characteristics, load
characteristics, and low temperature characteristics are all excellent,
and a battery using it. A cathode and an anode are layered and wound with
a separator and electrolyte layer in between. The electrolyte layer
contains an electrolytic solution containing at least one from the group
consisting of vinylethylene carbonate and its derivatives in the range of
0.05 wt % to 5 wt % in total and a polymer. Therefore, chemical stability
of the electrolyte layer is improved. It is preferable that the
electrolytic solution further contains ethylene carbonate and propylene
carbonate with a mass ratio of ethylene carbonate to propylene carbonate
ranging from about 15/85 to about 75/25.