High-capacity and high-rate Ni-Fe batteries based on mesostructured quaternary carbon/Fe/FeO/FeO hybrid material.

The Ni-Fe battery is a promising alternative to lithium ion batteries due to its long life, high reliability, and eco-friendly characteristics. However, passivation and self-discharge of the iron anode are the two main issues. Here, we demonstrate that controlling the valence state of the iron and coupling with carbon can solve these problems.