Nanosized ReS2 Monolayers Embedded in Nitrogen-Doped Carbon Nanotubes for High-Rate Capacitive Lithium Storage

The expected approach to improve the electrochemical performance of layered transition metal dichalcogenides is to thin them down to monolayer for minimizing the barrier of lithium-ion intercalation and diffusion. In this work, a distinct nanocomposite constructed from nanosized ReS 2 monolayers uniformly embedded in nitrogen-doped carbon nanotubes is synthesized via a facile hydrothermal method followed by calcination. When evaluated as anode materials for lithium ion batteries, the robust nanocomposites exhibit a reversible capacity of 825 mAh g −1 at 100 mA g −1 after 100 cycles with an initial Coulombic efficiency as high as 83%, and more importantly, retain an outstanding capacity of 612 mAh g −1 at 1 A g −1 after 500 cycles with an excellent capacity retention of 80%. Kinetics analysis of the redox reactions reveals that 86% of the charge storage is controlled by a capacitive behavior, leading to both high-rate and long-life lithium storage performances. The design of the nanocomposites offers a promising strategy to achieve extra power over batteries by capacitive energy storage.