Four-way valve for battery circulation system

摘要

A circulation system for a flowing-electrolyte battery having at least one electrochemical cell, an anolyte reservoir, and a catholyte reservoir. The circulation system includes an anolyte pump coupled in fluid flowing relationship to the anolyte reservoir which pumps anolyte from the anolyte reservoir to the at least one electrochemical cell. A catholyte pump is coupled in fluid flowing relationship to the catholyte reservoir and also pumps catholyte to the at least one electrochemical cell. A second phase pump is coupled in fluid flowing relationship to the catholyte reservoir and is used to introduce second phase electrolyte into the aqueous catholyte pumped by the catholyte pump. The second phase pump is controlled by a controller so that the second phase is introduced into the catholyte stream in a metered fashion. A controllable four-way valve is coupled in fluid flowing relationship to the catholyte pump and operable to direct the flow of catholyte through the electrochemical cell in a first direction, and periodically reverse the flow of the catholyte in a second direction. Metering the amount of second phase injected into the catholyte stream and reversing catholyte flow improve battery efficiency.