Boosting Surface-Dominated Sodium Storage of Carbon Anode Enabled by Coupling Graphene Nanodomains, Nitrogen-Doping, and Nanoarchitecture Engineering

The development of high-performance carbon anode for sodium-ion batteries is limited by the sluggish kinetics and structural instability. Expanded interlayer spacing, nitrogen doping, and mesoporous structure engineering have emerged as promising strategies to overcome these challenges. Simultaneously achieving graphene nanodomains construction, high-efficient nitrogen doping, and rational mesoporous structure engineering is challenging. Herein, a strategy of pyrolyzing SiO2@ lignin amine urea-formaldehyde resin is proposed for deliberate manipulation of graphene nanodomains, edge-nitrogen doping, and specific mesoporous distribution in amorphous lignin-derived carbon based on polycondensation-template. The obtained carbon material exhibits a nitrogen-doping level of 6.03 at% with a high edge-nitrogen ratio of up to 84.4%, high- connectivity mesoporous structure, and graphene nanodomains with expanded interlayer spacing. The optimized carbon material delivers a reversible capacity of 234 mAh g(-1) at 100 mA g(-1), superior rate capability of 129 mAh g(-1) at 2 A g(-1), and excellent cycling stability. In addition, the surface-dominated sodium-ion storage mechanism is identified by in situ electrochemical impedance spectroscopy. Furthermore, the optimized carbon can function as an outstanding anode for full cells. This work proposes a new avenue for designing high-performance carbon for low-cost and high-rate sodium-ion batteries.

Automated summary

A strategy of pyrolyzing SiO2@lignin amine urea-formaldehyde resin is proposed for deliberate manipulation of graphene nanodomains, edge-nitrogen doping, and specific mesoporous distribution in amorphous lignin-derived carbon based on polycondensation-template. The optimized carbon material exhibits high nitrogen-doping level, high- connectivity mesoporous structure, and expanded interlayer spacing in graphene nanodomains, leading to excellent electrochemical performance and identified surface-dominated sodium-ion storage mechanism. The optimized carbon also shows outstanding performance as an anode for sodium-ion batteries.