Cr2O3 ultrasmall nanoparticles filled carbon nanocapsules deriving from Cr(VI) for enhanced lithium storage

Abstract

Based on the considerations in environmental and economic benefits, Cr2O72− as the major chromium pollutant is employed for applications in energy storage. A novel Cr2O3 ultrasmall nanoparticles (NPs) (<5 nm) filled carbon nanocapsule configuration is achieved through a surfactant-free solvothermal route with renewable furfural as the carbon source. The confinement effect that Cr2O3 NPs are restrained in the outer robust carbon shell and the plenty space among Cr2O3 NPs result in substantially enhanced Li-storage performances, such as stable capacity of 568 mAh g−1 at 100 mA g−1 after more than 200 cycles and high capacity retention at large current density.