3D Graphene-like Microporous Carbon for Ultralong-Life Lithium-Ion Capacitors

The hybrid Li-ion capacitor (LIC) is one of the most promising energy storage platforms, offering the advantages of the energy density of the Li-ion battery (LIB) and the power density of the supercapacitor. However, challenges remain in developing high-performance LICs due to the sluggish ion diffusion at the LIB anode and the fast electrostatic interaction of the ions at the supercapacitor cathode, resulting in an imbalance of ion transfer between the electrodes. Here, we report the exceptionally high LIC performance of 3D graphene-like microporous zeolite-templated carbon (ZTC). The ZTC was synthesized by using beta zeolite as a hard template and ethylene as a carbon source. The resultant ZTC was characterized by the sp² framework with a high surface area of 3400 m² g^-1 and a high Li-ion storage capacity of 1870 mA h g^-1. The prelithiated ZTC electrode (ZTC_Li) was used as the LIB anode, and the as-made ZTC electrode was used as the supercapacitor cathode in the hybrid LIC (ZTC_Li // ZTC). The ZTC_Li // ZTC LIC demonstrated remarkably high energy and power densities and cycling stability for over 30,000 cycles. These outcomes were attributed to the facilitated Li-ion adsorption/desorption by the ion desolvation in the pore environment with narrow size distribution (ca. 1 nm in diameter).