Rice husk-derived hybrid lithium-ion capacitors with ultra-high energy

Inspired by nature, both high-performance Si/C and activated carbon (AC) energy storage materials with a hierarchically biomimetic structure can be prepared from rice husks (RHs), and further serve as promising anode and cathode materials for hybrid lithium-ion capacitors (LICs), respectively. Benefitting from the high capacity and good rate and cycling performances of the Si/C anode material and RH-derived AC (RAC) cathode material, the designed Si/C||RAC LICs give a high energy density of 227 W h kg−1 at a power density of 1146 W kg−1, and ∼181 W h kg−1 can still be retained even at an ultra-high power density of ∼32 595 W kg−1. Furthermore, the RH-derived LICs also show a long-term cycling stability (16 000 cycles at ∼16 800 W kg−1).