Pore structure design via modified phase inversion strategy toward high-performance hard carbon anode

Pore structure engineering is vital for hard carbon (HC) anodes but remains challenging. We developed a phase inversion-based strategy using polyacrylonitrile and sodium lignosulfonate to regulate pore size distribution and wall chemistry during carbonization. The resulting HC anode delivers 305 mAh g^-1 at 0.1C and 68% capacity retention at 2C, due to enhanced ion accessibility and robust frameworks. It also performs excellently in sodium-ion capacitors, providing a novel design route for high-performance HCs.