Overview: Current trends in green electrochemical energy conversion and storage

Nowadays, hydrogen technologies like fuel cells (FC) and electrolyzers, as well as rechargeable batteries (RBs) are receiving much attention at the top world economies, with public funding and private investments of multi-billion Euros over the next 10 years. Along with these technologies, electrochemical capacitors (ECs) are expanding rapidly in the energy storage market. Electrolyzers, RBs, FCs and ECs are electrochemical energy conversion and storage devices offering environmental and sustainable advantages over fossil fuel-based system. This overview discusses current trends in these electrochemical systems. It also examines recent advances on the CO2 reduction reaction, which has gained attention because of the capability of producing value-added chemical products at high efficiencies from the main greenhouse gas in the USA and the European Union. It is expected that these green systems will play a key role in the imminent implementation of a global sustainable energy scenario.