Synthesis of pitch-derived carbon anodes for high-performance potassium-ion batteries

• Pitch-derived soft carbons with tunable structures were synthesized by carbonization at 600–1400 °C, revealing clear correlations between carbon microstructure and potassium storage performance. • The carbon obtained at 700 °C exhibited a high degree of disorder and large interlayer spacing, delivering a high reversible capacity of 329.4 mAh g−1 and an initial coulombic efficiency of 72.81%. • The low-potential plateau capacity correlates with carbon crystal size, while the sloping region capacity is linked to the degree of structural disorder, providing mechanistic insights into K+ storage. • The optimized carbon anode maintained a high capacity of 144.2 mAh g−1 at a high current rate of 5 C, demonstrating excellent rate capability for potassium-ion batteries.