Recent advances of two-dimensional transition metal nitrides for energy storage and conversion applications

Electrochemical energy storage and conversion devices have attracted global attention due to the increasing energy demand. Since the performance of energy devices is largely affected by the electrode materials, tremendous efforts have been devoted to developing advanced electrode materials with superior electrochemical properties such as large energy and power densities for energy storage and conversion systems. On the heels of the discovery of graphene, two-dimensional (2D) nanomaterials have attracted great research interest on account of the large specific surface area, unique electronic structure, and fascinating physicochemical properties and are alternative electrode materials in electrochemical energy storage systems. Among them, transition metal nitrides (TMNs) are suitable for a myriad of devices because they have better electrical conductivity than oxides and excellent catalytic properties. Although there are several reviews about TMNs for electrochemical energy storage or water splitting, a review of recent advances of 2D TMNs materials is still scarce. In this mini-review, recent progress on 2D TMNs as high-performance electrode materials in energy storage and conversion devices is summarized. The synthesis strategy and applications to energy-related areas, including lithium-ion batteries, supercapacitors, Li-S batteries, and electrocatalysts are presented. Moreover, challenges and perspectives for 2D TMNs-based materials for energy storage and conversion devices are described.