A facile and versatile strategy towards high-performance Si anodes for Li-ion capacitors: Concomitant conductive network construction and dual-interfacial engineering

In this work, we demonstrate an efficiency and versatile strategy for the synthesis of Si-based anodes using low-cost biomass and commercially available Si nanoparticles as precursors via conventional slurry coating and low-temperature pyrolysis . Due to the tailored and rational design, gelatin-derived carbon with numerous heteroatoms not only acts as a “conductive skeleton” to enhance the electron/ion transfer but also simultaneously accommodate the Si expansion and immobilize the Si on the current collector via “dual-interfacial bonding”. Without additional binder and conductive agents, the obtained Si-based anode exhibits high initial columbic efficiency (85.3%), high gravimetric capacity (3160 mAh g −1 at 0.2 A g −1 ), large areal capacity (2.81 mAh cm −2 at 0.18 mA cm −2 , approaching the commercial LIB requirement), good rate capability (1613 mAh g −1 at 5 A g −1 ) and cycling performance. Consequently, an assembled Li-ion capacitor utilizing the Si-based anode exhibits high energy density (213 Wh kg −1 ), high power density (22.3 kW kg −1 ), low discharge rate and long lifetime. The scalable synthetic method combined with high performance making this Si-based anode promising for practical applications.