Defect-rich N/O-co-doped porous carbon frameworks as anodes for superior potassium and sodium-ion batteries

• A defect-rich porous carbon framework (DRPCF) with N/O co-doping was synthesized using porous g-C3N4 and dopamine, achieving a high specific surface area and abundant active defect sites. • The optimized DRPCF-2/1-700 anode exhibited exceptional sodium storage capacity of 328.2 mAh g−1 after 900 cycles at 1 A g−1 and potassium storage capacity of 321.5 mAh g−1 after 1200 cycles at 1 A g−1. • The superior performance is attributed to pseudocapacitive storage and the reversible filling/removal of Na+ and K+ in electrochemically active defects, as confirmed by ex-situ Raman spectroscopy. • The rate capability and cycling stability of DRPCF-2/1-700 outperform most reported carbon materials, highlighting its potential for advanced sodium and potassium-ion batteries.