Zn/Co bimetallic metal-organic framework derived carbon anode with enchanted rate capability for lithium-ion capacitors

Abstract

Lithium-ion capacitors (LICs) combine the advantages of lithium-ion batteries and supercapacitors, demonstrating great application prospects in the fields of large-scale renewable energy, and have been attracting increasing attention. Regrettably, the power capability of LICs is significantly hindered by the incongruent kinetics between battery-type anodes and capacitive cathodes. To address this challenge, in this study, a carbon anode derived from Zn/Co bimetallic metal-organic framework (MOF), specifically the Zn80Co20-PC, is synthesized through a direct carbonization process. Benefitting from the optimal degree of graphitization, substantial specific surface area, and comprehensive porous structure, the incongruent behaviour is effectively alleviated. As a result, the battery assembled with Zn80Co20-PC yielded an impressive capacity of 397.1 mAh g−1 at a current density of 0.1 A g−1 and a commendable rate capability of 109.6 mAh g−1 at 1.6 A g−1. Moreover, the LICs crafted with a pre-lithiated Zn80Co20-PC anode and an activated carbon (AC) cathode (designated as Zn80Co20-PC//AC LICs) exhibit a notable energy density of 123 Wh kg−1 and an elevated power density of 7150.3 W kg−1, maintaining exceptional durability through 5000 cycles. This study introduces innovative strategies for integrating advanced anode materials into lithium-ion capacitors.