Single-Crystalline SnSe₂ Nanosheets with\nEnhanced Lithium Storage Properties

Abstract

Two-dimensional\n(2D) IV–VI nanomaterials have been important\ncandidates for energy conversion and storage. However, there is still\nlack of a simple method of realizing control synthesis of IV–VI\nnanosheets. In this work, single-crystalline tin diselenide (SnSe₂) nanosheets with a thickness of ca. 9 nm and a micrometer\nlateral size have been successfully synthesized through a hot-injection\ncolloidal method. An evolution process study indicates that SnSe₂ nanosheets are synthesized through coalescence of SnSe₂ nanoparticles in an orientation attachment mechanism. The\nobtained SnSe₂ nanosheet anodes delivered a high reversible\ncapacity of 512 mA h g^–1 with a coulombic efficiency\nof 98% at the current density of 0.1 A g^–1, attributed\nto their special layered nanoarchitectures, which facilitates lithium\nion (Li⁺) interfacial diffusion and storage. This work\nprovides a meaningful approach to synthesizing single-crystalline\n2D nanomaterials for energy storage applications.