The two-dimensional layered material of Sn(HPO4)2 nanosheets (SNSs) with a controllable nanosheet structure and a large interlayer distance is expected to be a potential anode material for sodium ion storage. However, poor conductivity and easy agglomeration are daunting challenges to realize the practical application of the SNS as an anode material. To overcome these difficulties, a two-dimensional multilayered architecture composed of SNSs and reduced graphene oxide (rGO) is assembled by utilizing the electrostatic repulsion between the SNS and graphene oxide and by an assisting liquid nitrogen rapid freezing method. Mainly owing to the solid solution reaction mechanism of SNSs, the excellent conductivity and interfacial charge storage of rGO, and their interaction with each other, the rGO/SNS anode exhibits improved rate capability, outstanding cycling stability of 78.6% capacity retention after 10,000 cycles at 5 A g–1, and high pseudocapacitance of a 66% capacitive contribution ratio at 0.5 mV s–1. This work is expected to promote the development of SNS-based nanomaterials for electrochemical energy storage.

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Lithium/sodium-ion capacitors (LICs/SICs), based on the combination of Faradaic characteristics and capacitance behavior of a hybrid electrochemical storage mechanism, are expected to realize better power density and cycle life than lithium/sodiumion batteries and higher energy density than supercapacitors. However, the serious mismatch of electrochemical reaction kinetics of the battery-type anode controlled by sluggish solid-state diffusion and the capacitor-type cathode depending on rapid surface ion adsorption restricts their electrochemical performance. Pseudocapacitance, as a bridge between traditional doublelayer capacitors and typical rocking chair batteries, can bridge the gap between power and energy density. Up to now, two-dimensional layered materials with controllable nanosheet structure, large interlayer distance, and expectable tunable intercalation have shown considerable pseudocapacitive behaviors. In this paper, the recent progress in the research of advanced two-dimensional layered compound-based anode materials for LICs/SICs with controllable tuning of pseudocapacitive responses realized by effective strategies for material design is reviewed. This paper also discusses the challenges and possible developing trends for the future development of twodimensional high pseudocapacitance anode materials in building high energy and power density LICs/SICs.