Lithium‑ion capacitors (LICs) integrate the high‑energy advantage of lithium‑ion batteries and high‑power merit of supercapacitors, yet their practical application is restricted by severe kinetic mismatch between faradaic battery‑type anodes and capacitive adsorption‑type cathodes. Low‑cost, tunable‑structure coal provides a promising precursor for energy‑storage carbon materials. In this work, Xinjiang Hami long‑flame coal was adopted to fabricate a series of coal‑based cathode and anode materials via KOH activation, high‑temperature carbonization, oxidative exfoliation and sulfur‑nitrogen co‑doping. The structure‑performance relationship of coal‑based carbon was systematically investigated. The KOH‑activated coal‑based AC‑2 cathode delivers 3411.5 m²·g⁻¹ hierarchical micro‑mesoporous structure and 69 mAh·g⁻¹ specific capacity. Two kinds of anodes including hard‑carbon HC‑2 and two‑dimensional carbon nanosheet CNS‑2 were prepared. Assembled LICs with homologous coal‑based electrodes exhibit favorable energy‑power output and cycling stability. Further sulfur‑nitrogen co‑doping yields SNCNS‑3 anode with abundant defects and pseudocapacitive sites, achieving 491 mAh·g⁻¹ reversible capacity. The corresponding LIC reaches an energy density of 89.47 Wh·kg⁻¹ at 297.68 W·kg⁻¹. This work demonstrates the great prospect of coal‑derived carbon for constructing high‑performance LIC devices.
 

Lithium‑ion capacitor; coal‑based carbon material; carbon nanosheet; heteroatom doping; kinetic matching