Ni3S2@Graphene oxide nanosheet arrays grown on NF as binder-free anodes for lithium ion batteries.

A novel graphene oxide encapsulated Ni 3 S 2 multi-layer nanosheet arrays were designedly grown on Ni foam (Ni 3 S 2 @GO/NF) via a simple and low-cost method. The prepared nanocomposite was converted from a pyramid shape to a multi-layer nanosheet array because Sn4+, Ni2+ and thioacetamide performed a coprecipitation transformation during the hydrothermal reaction. As a binder-free anode material for lithium ion batteries, the Ni 3 S 2 @GO/NF nanocomposite showed an initial charge and discharge of 797.8 and 1182.3 mA h g−1 at a current density of 0.5 A g−1, respectively. After 100 reversible cycles, the specific discharge capacity of the composite can still remain 1006.6 mA h g−1, presenting excellent cycle stability. The enhanced electrochemical performance is due to that the multi-layer sheet array structure can increase the Li+ energy storage active site and alleviate the volume expansion caused by Li+ insertion and extraction, which was beneficial to the sufficient contact of the active material with the electrolyte, enhancing the lithium ion transmission rate. Additionally, the coating of oxide graphene on the composite further stabilized the structural morphology, thereby improving the stability of the electrochemical cycle performance of the nanocomposite. • The novel nanosheet arrays were directly grown in situ on NF skeleton. • The addition of Sn4+ could regulate the shape of the arrays. • Ni 3 S 2 @GO/NF nanosheet arrays can be used as binder-free anodes for LIBs. • The nanosheet arrays structure could increase the active sites of Li+ storage and alleviate the volume expansion. • The GO coating could improve the conductivity, total capacity and cycle stability of Ni 3 S 2 @GO/NF. [ABSTRACT FROM AUTHOR]