In-situ growth of vertically aligned MoS2 nanowalls on reduced graphene oxide enables a large capacity and highly stable anode for sodium ion storage.

MoS 2 has attracted remarkable attention, attributed to its high specific capacity and graphite-like structure. However, the low rate capability and poor cycle stability are two major obstacles that hinder the practical application of MoS 2 in sodium-ion batteries (SIBs). Herein, MoS 2 grows vertically on the surface of reduced graphene oxide (rGO) and forms a nanowall structure by electrostatic attraction, whose growth has been induced by cetyltrimethyl ammonium bromide (CTAB). This unique nanowall has a large specific surface area, which not only exposes plenty of active sites and shortens the diffusion distance of Na+, but also improves the electronic conductivity and structural stability. Meanwhile, detailed kinetic analysis is also employed to explain the Na+ storage behavior. The pseudo capacitance-dominated contribution ensures a more stable and much faster Na+ storage. Therefore, the MoS 2 @rGO composite displays excellent electrochemical performance. For example, the capacity of the MoS 2 @rGO composite can still be maintained at 571.5 mA h g−1 with 94.1% retention, after 100 cycles at 0.1 A g−1. Impressively, MoS 2 @rGO still exhibits a considerable capacity of 124 mA h g−1 at an ultra-high current density of 40 A g−1. The excellent performance makes the MoS 2 @rGO material a prospective electrode for use in large-scale SIBs. Image 1 • The MoS 2 nanowalls grow vertically on the rGO surface by electrostatic attraction. • The combination of MoS 2 nanowalls and rGO is strengthened by forming a C–S bond. • The composite with MoS 2 nanowalls structure has a large specific surface area. • The MoS 2 nanowalls allows Na+ to deintercalate rapidly along the horizontal direction. • The MoS 2 @rGO composite shows superior cycle and rate performance in SIBs. [ABSTRACT FROM AUTHOR]