A comprehensive overview of MXene‐based anode materials for univalent metal ions (Li+, Na+, and K+) and bivalent zinc ion capacitor application

Abstract The excellence of MXene electrode material for high performance battery and supercapacitor devices represents immense possibility to construct MXene‐based metal ion capacitors (MICs) with a high energy/power density and long cyclic life. Various reports indicate that the MXene and its composites/heterostructures can be a suitable anode material to assemble MICs in non‐aqueous/aqueous electrolytes. The pillaring of MXenes with Sn 4+ , Fe 2 O 3 , TiO 2 , Fe 3 O 4 /C, SnO 2 , NaNbO 3 , MoS 2 , CNTs, graphene, etc. effectively alleviates restacking of nanosheets and provides large interlayer spacing as well as additional active sites. Formation of three‐dimensional network with porous structures and heteroatom doping are also advantageous for high performance electrode materials. Results indicate that the MICs can achieve a high energy density (up to 241 Wh kg −1 ) like rechargeable battery, a high power density (up to 25,000 W kg −1 ) like supercapacitor, and a satisfactory cyclic stability. This article reviews state‐of‐the art MXene‐based anode materials for various MICs. After a brief introduction about the MICs, its storage principle, historical background, and insights of the MXene synthesis, property, and storage mechanism, the article summarizes/evaluates the electrochemical performance of various MICs assembled by the MXene‐based anode materials. Finally, we outline challenges/future prospects of the MICs using MXene‐based anode materials.