Metal-Organic Framework-Derived Anode and Polyaniline Chain Networked Cathode with Mesoporous and Conductive Pathways for High Energy Density, Ultrafast Rechargeable, and Long-Life Hybrid Capacitors

Hybrid lithium-ion energy storage devices are promising for future applications, but their anodes and cathodes still have structural limitations, for example, accommodating rich cationic/anionic reactions, rapid charge movement, and long cycle life. Herein, high-capacity/high-rate anode and cathode structures are developed to overcome these challenges. Molybdenum oxide (MoO2)-implanted carbon frameworks making conductive carbon bonds with reduced graphene oxide (rGO) shells are developed as anode structures by forming mesoporous channels for fast lithium-ion transport, carbon-rGO pathways for facile electron conduction, and ultrafine MoO2 units for high capacity. The operando X-ray diffraction and kinetics analyses reveal that lithium-ion insertion and extraction occur via capacitive and diffusion-controlled reactions. Also, polyaniline (PANI) chains are elongated on rGO sheets through in situ polymerization to form crosslinked polyaniline chain-integrated rGO as cathode structures. These display multiporosity for rapid anion transport, N-doping sites for high capacity, and pi-pi bonding between PANI and rGO for electron conduction and cycle stability. Moreover, hybrid capacitors configured by this anode and cathode allow for the exploitation of battery-type and pseudocapacitive reactions, as demonstrated by their extremely high energy density (up to 242 Wh kg(-1)), ultrafast chargeable power density (up to 28 750 W kg(-1)), and long-life stability over 10 000 cycles.