Performance of an environmentally benign acid base flow battery at high energy density
Egmond, W.J. van; Saakes, M. ; Noor, I. ; Porada, S. ; Buisman, C.J.N. ; Hamelers, H.V.M. - \ 2018
International Journal of Energy Research 42 (2018)4. - ISSN 0363-907X - p. 1524 - 1535.
acid base flow battery - bipolar membrane - co-ion transport - energy efficiency - ion exchange membranes - renewable energy storage - sustainable materials
An increasing fraction of energy is generated by intermittent sources such as wind and sun. A straightforward solution to keep the electricity grid reliable is the connection of large-scale electricity storage to this grid. Current battery storage technologies, while providing promising energy and power densities, suffer from a large environmental footprint, safety issues, and technological challenges. In this paper, the acid base flow battery is re-established as an environmental friendly means of storing electricity using electrolyte consisting of NaCl salt. To achieve a high specific energy, we have performed charge and discharge cycles over the entire pH range (0–14) at several current densities. We demonstrate stable performance at high energy density (2.9 Wh L−1). Main energy dissipation occurs by unwanted proton and hydroxyl ion transport and leads to low coulombic efficiencies (13%–27%).