Nickel-templated carbon foam anodes for sodium-ion batteries

Sodium-ion batteries, which are abundant in resources and cost-effective, are widely considered to be suitable for large-scale energy storage. However, unstable intercalation compounds and large sodium ion radius cause carbonaceous anodes to perform poorly. Herein, a soft-and-hard composite hollow carbon foam (HCF) was one-step prepared by nickel-templated blowing strategy. The sodium-ion storage performances were enhanced by soft carbon skeleton with high conductivity, hard carbon with abundant pores, and nitrogen doping. When applied as anodes for sodium-ion storage, HCF demonstrates remarkable capacity, rate, and cycling performances. It de-livers 256 mAh g-1 at 0.05 A g-1 and can be cycled for 2000 times at 1 A g-1 with remaining a capacity of 139 mAh g-1. Kinetic studies reveal that soft-and-hard carbon structure, nitrogen doping, and porous structure can effectively promote sodium-ion absorption, as well as the transport of electrons and ions. Therefore, sodium -ion batteries based on the carbon could facilitate the development of renewable energy sources.

Automated summary

A soft-and-hard composite hollow carbon foam (HCF) was prepared using a nickel-templated blowing strategy, which showed remarkable sodium-ion storage performances due to its soft carbon skeleton, abundant pores, and nitrogen doping. The HCF delivered a capacity of 256 mAh g-1 at 0.05 A g-1 and cycled for 2000 times at 1 A g-1 with a remaining capacity of 139 mAh g-1.