Feasibility study of amperometric and electrochemical quartz crystal microbalance measurements for in situ state of charge monitoring in vanadium flow batteries

For an efficient flow battery operation, knowledge of the state of charge of the battery is essential. Monitoring the state of charge of both half cells is advantageous concerning a timely detection of crossover processes. We present the first results for amperometric and electrochemical quartz crystal microbalance measurements in a vanadium flow battery test setup. By validating with half cell potential measurements as well as ex situ titration we investigate the applicability of both electrochemical methods for an in situ half cell state of charge monitoring.