Achieving All Plateau and High Capacity Sodium Insertion in Topological Graphitized Carbon.

Hard carbon anodes with all-plateau capacities below 0.1 V are prerequisites to achieve high energy density sodium ion storages, which are holding promises for the future sustainable energy technologies. However, challenges in removing defects and improving the insertion of sodium ions heading off the development of hard carbon to achieve this goal. Herein, we reported a highly cross-linked topological graphitized carbon using biomass corn cobs through a two-step rapid thermal annealing strategy. The topological graphitized carbon constructed with long-range graphene nanoribbons and cavities/tunnels provides a multi-directional insertions of sodium ions whilst eliminating defects to absorb sodium ions at high voltage region. Evidences from advanced technique including in-situ XRD, in-situ Raman and in-situ/ex-situ TEM indicate that the sodium ions appear Na cluster formation between curved topological graphite layers and in the topological cavity of adjacent graphite band entanglements. The reported topological insertion mechanism enables outstanding battery performance with a single full low-voltage plateau capacity of 290 mAh g -1 , which is almost 97% of the total capacity. This article is protected by copyright. All rights reserved.