The present disclosure provides an integrated flow battery stack with a heat exchanger for thermal control of the battery during operation. The battery can comprise a stack consisting a plurality of electrochemical cells, each cell comprising a pair of electrodes separated by a membrane and sandwiched between a pair of bipolar plates. Each bipolar plate is shared between two adjacent cells. The stack is connected to an external electrical circuit by two current collectors placed at each end of the stack. At least one current collector plate is thermally coupled to a heat exchange plate which can be configured to have its temperature varied through external means. The heat exchange plate exchanges heat with the battery stack and maintains the temperature of the stack, by implication, maintains the temperature of the circulating electrolytes.