Advanced Two-Dimensional Layered Compound-Based Materials for High Performance Lithium/Sodium-Ion Capacitors

Lithium/sodium-ion capacitors (LICs/SICs), based on thecombinationof Faradaic characteristics and capacitance behavior of a hybrid electrochemicalstorage mechanism, are expected to realize better power density andcycle life than lithium/sodium-ion batteries and higher energy densitythan supercapacitors. However, the serious mismatch of electrochemicalreaction kinetics of the battery-type anode controlled by sluggishsolid-state diffusion and the capacitor-type cathode depending onrapid surface ion adsorption restricts their electrochemical performance.Pseudocapacitance, as a bridge between traditional double-layer capacitorsand typical rocking chair batteries, can bridge the gap between powerand energy density. Up to now, two-dimensional layered materials withcontrollable nanosheet structure, large interlayer distance, and expectabletunable intercalation have shown considerable pseudocapacitive behaviors.In this paper, the recent progress in the research of advanced two-dimensionallayered compound-based anode materials for LICs/SICs with controllabletuning of pseudocapacitive responses realized by effective strategiesfor material design is reviewed. This paper also discusses the challengesand possible developing trends for the future development of two-dimensionalhigh pseudocapacitance anode materials in building high energy andpower density LICs/SICs.