Surface Stretching Enables Highly Disordered Graphitic Domains for Ultrahigh Rate Sodium Storage

Hard carbons (HCs) with high sloping capacity are considered as the leading candidate anode for sodium-ion batteries (SIBs); nevertheless, achieving basically complete slope-dominated behavior with high rate capability is still a big challenge. Herein, the synthesis of mesoporous carbon nanospheres with highly disordered graphitic domains and MoC nanodots modification via a surface stretching strategy is reported. The MoOx surface coordination layer inhibits the graphitization process at high temperature, thus creating short and wide graphite domains. Meanwhile, the in situ formed MoC nanodots can greatly promote the conductivity of highly disordered carbon. Consequently, MoC@MCNs exhibit an outstanding rate capacity (125 mAh g(-1) at 50 A g(-1)). The adsorption-filling mechanism combined with excellent kinetics is also studied based on the short-range graphitic domains to reveal the enhanced slope-dominated capacity. The insight in this work encourages the design of HC anodes with dominated slope capacity toward high-performance SIBs.

Automated summary

This study reports a surface stretching strategy for synthesizing mesoporous carbon nanospheres with highly disordered graphitic domains and MoC nanodots modification. The MoOx surface coordination layer inhibits the graphitization process and creates short and wide graphite domains. In-situ formed MoC nanodots greatly enhance the conductivity of highly disordered carbon. Consequently, MoC@MCNs exhibit outstanding rate capacity (125 mAh g(-1) at 50 A g(-1)). The study provides insights for designing HC anodes with dominated slope capacity for high-performance SIBs.