Lawrence Berkeley National Laboratory
All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications
- Author(s): Tucker, MC
- Phillips, A
- Weber, AZ
- et al.
Published Web Locationhttps://doi.org/10.1002/cssc.201500845
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. An all-iron redox flow battery is proposed and developed for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. The design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe2(SO4)3active material and 1.2 m NaCl supporting electrolyte. With these materials, an average power density around 20 mW cm-2and a maximum energy density of 11.5 Wh L-1are achieved. A simple cost model indicates the consumable materials cost US6.45 per kWh-1, or only US0.034 per mobile phone charge.