MOF-Derived Onion-Like Carbon with Superior Surface Area and Porosity for High Performance Lithium-Ion Capacitors

Abstract

Lithium-ion capacitors (LICs), potentially bring together the advantages of batteries and supercapacitors. For the faradaic anodes, nanostructured carbonaceous materials hold immense potential, in contrast to graphite where limitations in Li-ion diffusivity exist. Herein, onion-like carbons (OLCs), synthesized from Fe-BTC metal-organic framework (MOF), is implemented as the LIC anode, owing to its high charge storage capacity and rate capability as compared to graphite. The enhanced charge storage and Li-ion transference in OLCs was understood to be due to hierarchical porosity with accessible inner voids along with high defect concentration. Therefore, full-LIC cells with OLC anodes exhibited a markedly higher specific capacitance and an enhanced rate capability than graphite-LIC. The OLC-LIC achieved an outstanding maximum energy density of 224 Wh kg−1 at 122 W kg−1 and maximum power density of 14436 W kg−1 at 80 Wh kg−1. Thus, MOF-derived OLC with distinctive morphology is presented as a highly attractive anode for practical LIC systems.