Single-Crystalline SnSe2 Nanosheets with Enhanced Lithium Storage Properties

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