Recovery of transition metal ions with simultaneous power generation by reverse electrodialysis

Renewable energy processes based on salinity gradient differences possess spreading interests as an alternative to energy production methods based on fossil fuels. The reverse electrodialysis (RED) process is used for energy production by mixing seawater and river water. In the proposed solution, the spent battery effluent is applied as a high-concentrated solution for the first time, generating a potential difference in the RED stack. The highselective cation exchange membrane for cobalt transportation in the RED system was a demanding barrier controlling the separation behaviour. The initial research confirmed the energy production ability from mixing high concentrated (HC) solution of Co2+, Li+ and Ni2+ nitrates and low concentrated (LC) solution containing chloric acid. The maximum extracted energy was estimated at 0.44 W/m2 with an energy efficiency of 45.5%. The presented method is a promising candidate for dealing with battery waste management and converting it into a valuable product such as cobalt salts with the potential for power harvesting.