Review of solid oxide electrolysis cells: a clean energy strategy for hydrogen generation

Hydrogen is an environmentally friendly alternative to conventional fossil fuels and is considered as a renewable energy carrier for meeting the ever-increasing energy demand. Although hydrogen is abundant on earth in the form of compounds such as water, producing molecular hydrogen demands a large amount of energy. A solid oxide electrolysis cell (SOEC) is an electrochemical device which generates hydrogen from various sources. An SOEC uses high temperature (>800°C) to electrolyse water with high efficiency assisted by thermodynamically favoured water splitting that enables large-scale hydrogen production. This review provides a comprehensive overview of the current status in the developments of high-temperature steam electrolysis using a proton- and oxygen-ion-conducting SOEC system for hydrogen production. The present review summarises the detailed approaches for hydrogen production u…