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

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. Towards high‐performance Li‐ion capacitor: The metal organic framework (MOF)‐derived onion‐like carbon (OLC) material, although already reported, is a promising carbonaceous anode for hybrid Li‐ion capacitor (LIC), with high surface area and porosity, along with accessible inner void, facilitating better charge storage. Herein, LICs with MOF‐derived OLCs as anode demonstrate significantly higher energy and power density in comparison to LICs with conventional graphite anodes.