用于实现钠离子电容器动力学匹配的快充铋碳复合负极OA

Sodium-ion capacitors(SICs)typically feature a hybrid design,incorporating a battery-type anode that operates by faradaic redox reactions and an activated carbon cathode that functions through electrical double-layer(EDL)adsorption/desorption.However,the kinetics of faradaic processes are in-herently slower than those of EDL processes,lead-ing to a fundamental problem known as kinetic im-balance between the electrodes,which hinders the development of high-performance SICs.To address this,we synthesized composites of bismuth nano-particles in N-doped carbon(Bi@NC)by a high-temperature sintering method.The resulting Bi@NC anode has a specific capacity of 300 mAh g-1 at 0.5 A g-1,an exceptional rate capability(maintaining performance at currents exceeding 75 A g-1),and outstanding cycling sta-bility over 12 000 cycles.Three-electrode Swagelok cell tests revealed that this high-rate Bi@NC composite effectively de-creases the kinetic gap with the activated carbon cathode,as shown by an analysis of their respective potential swing windows(vs.Na/Na+).This enables the fabricated SIC to achieve a maximum energy density of 115 Wh kg-1,a peak power density of 45 535 W kg-1,and a long cycle life exceeding 8 000 cycles.