High Capacity and Superior Rate Performances Coexisting in Carbon-Based Sodium-Ion Battery Anode

Amorphous carbon is considered as a prospective and serviceable anode for the storage of sodium. In this contribution, we illuminate the transformation rule of defect/void ratio and the restrictive relation between specific capacity and rate capability. Inspired by this mechanism, ratio of plateau/slope capacity is regulated via temperature-control pyrolysis. Moreover, pore-forming reaction is induced to create defects, open up the isolated voids, and build fast ion channels to further enhance the capacity and rate ability. Numerous fast ion channels, high ion-electron conductivity, and abundant defects lead the designed porous hard carbon/Co3O4 anode to realize a high specific capacity, prolonged circulation ability, and enhanced capacity at high rates. This research deepens the comprehension of sodium storage behavior and proposes a fabrication approach to achieve high performance carbonaceous anodes for sodium-ion batteries.