W2C/porous graphene nanocomposite as an efficient non-noble metal catalyst for hydrogen and oxygen recombination in nickel–iron battery

Nickel–iron battery is highly desirable for energy storage systems in rural/remote areas for its safety, low cost, long cycle life. But it cannot be sealed and maintenance-free due to the hydrogen evolution reaction. Herein, we synthesized W 2 C nanocrystals embedded in porous graphene as catalysts for the hydrogen and oxygen recombination in the nickel–iron battery through in situ carburization of metallic W anchored on the graphene. The W 2 C/porous graphene nanocomposite catalyst exhibited a high performance with an average catalytic velocity of 3859 μmol h −1 g cat −1 and long catalytic life of 598,260 s without decay in the catalytic performance. With the non-noble metal catalyst of W 2 C/porous graphene nanocomposite, a nickel–iron battery could be sealed and maintenance-free, and it also exhibited low cost; thus, the nickel–iron battery can be used for large-scale energy storage systems in rural/remote areas.