Superficial-defect engineered nickel/iron oxide nanocrystals enable high-efficient flexible fiber battery

Doping engineering brings superficial defects in Ni/Fe oxide nanostructures with optimized band and electronic structures. The flexible full cell assembled with doped metal oxide based fibrous electrodes delivers ultrahigh volumetric energy density (61.0 mW h cm−3) and power density (48.4 W cm−3) with robust cycling and mechanical stability.287