Regulating Microstructure of Walnut Shell-Derived Hard Carbon for High Rate and Long Cycling Sodium-Based Dual-Ion Batteries

•Adjusting the DR/PGR ratio of WSC anode can effectively improve the Na+ storage.•WSC-1200 delivered a high reversible capacity of 336.5 mA h g−1 at 0.5 A/g.•WSC-1200 had a high-rate cycle life (106 mA h g−1 at 10 A/g over 10,000 cycles).•The assembled SDIB exhibited an ultra-long cycle life over 30,000 cycles.