Redox Flow Batteries for Fast EV Charging and for Hydrogen Production for FCEVs

Abstract

A service station for electric vehicles (EVs) and fuel cell EVs (FCEVs) has been constructed based on a vanadium redox flow battery (200kW-400kWh). This battery is used to fast charge EVs using a DC-DC converter operating at 80kW. We also operate two electrolyzers (one alkaline 50kW, one PEM 25 kW) to produce hydrogen. This hydrogen is dried, purified and stored at 200 bars. A service station for hydrogen has been built with reservoirs at 500 bars to fill a car (Renault Kangoo/Swiss hydrogen) operating at 350 bars and at 900 bars to fill a car operating at 700 bars (Hyundai). We shall discuss the figures of merit of electric and hydrogen mobility and our experience to run a service station in the Alps. We shall also present a new technology to produce hydrogen on demand and under pressure directly from a Vanadium (III)/(II) solution from the redox flow battery using a Mo2C catalyst. We shall also discuss the use of solid boosters to enhance the storage in the tanks of a redox flow battery.