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.