Charging method for charging nonaqueous electrolyte secondary battery

摘要

An initial charging operation is carried out by a charging step composed of two-stages or more to improve an initial charging and discharging efficiency, reduce the charge of wasteful materials and improve a high capacity and a high cyclic characteristic without deteriorating various kinds of battery properties. In order to realize the improvements, a nonaqueous solvent which is decomposed under a potential higher than the reduction and decomposition potential of a main solvent is included in electrolyte. This charging method is a method for achieving the addition effect of such a nonaqueous solvent as much as possible. As a specific means, the electrolyte to which vinylene carbonate is added is employed and a constant-current and constant-voltage charge under about 3.2 V is carried out for 1 to 2 hours before a battery is completely charged. Thus, a good coat can be formed on the surface of an anode while suppressing the quantity of electricity required for forming the coat.