Secondary cell and method of operating the secondary cell

Abstract

The invention provides a secondary battery system that allows a high overload operation regardless of discharging condition during a steady operation, and an operating method thereof. The secondary battery system comprises first tanks 31, 32 for reserving electrolytes required for a steady operation, and second tanks 33, 34 for reserving electrolytes required for an emergency operation. Valves 41-48 are opened and closed for allowing selective switching between the electrolytes in the first tanks 31, 32 and the electrolytes in the second tanks 33, 34 to circulate the selected electrolytes through a cell stack 100. The electrolytes reserved in the second tanks 33, 34 are electrolytes having a proportion of a quantity of active material produced in a charging reaction to a total quantity of active material of not less than 50%.

Dependencies are inferred from the claim text.