Ion-Mediated Carbon Microdomain Engineering Boosting Enhanced Plateau Capacity of Carbon Anode under High Rate...

Sodium-based dual-ion batteries (SDIBs) have been attracting increasing attention in recent years owing to their low cost, environmental benignancy, and high operating voltage. However, the sluggish ion kinetics of conventional carbon anodes that cannot match the fast capacitive anion intercalation behavior of graphite cathodes constraints on improving power density of SDIBs. Herein, we present an ingenious carbon microdomain engineering strategy to fabricate high-performance carbon anode with ion-mediated high-activity nitrogen species and molecular-scale closed-pore architectures. Experimental characterizations and theoretical investigations demonstrate that Zn²⁺-mediated structural engineering tailors oxidized nitrogen species, which proficiently accelerate the sodium-ion desolvation kinetics; meanwhile the acetate-mediated pore-forming process modulates closed pores, which synergistically afford abundant sodium storage sites for high plateau-region capacity. As a result, the optimized microdomain engineered carbon material (MEC₃) tailored with the optimal amount of zinc acetate demonstrates an outstanding plateau-region capacity of 253 mAh g^- 1 even at 1 C, among the highest reported values. Consequently, the MEC₃||expanded graphite dual-ion battery exhibits an unprecedented cycling stability at high current rate, maintaining 80.6% capacity retention after 10,000 cycles at 10 C, among the best reports. This microdomain engineering strategy provides a new design principle for overcoming kinetic limitations of carbonaceous materials in plateau-dominated sodium storage systems.