NiCo2S4 nanoparticles anchored in the 3D interpenetrating framework composed of GNs and CNTs toward enhanced sodium storage performance

Abstract

NiCo2S4 as a promising anode material for sodium ion batteries (SIBs) with rich redox potential and high theoretical specific capacity, but suffers the poor conductivity and severe volume expansion. The electrode materials with a three-dimensional (3D) framework can facilitate the migration of ions/electrons, enhance structural stability, and alleviate the volume expansion during charging/discharging. Herein, we report the NiCo2S4 nanoparticles anchored on a 3D interpenetrating framework consisting of graphene nanosheets (GNs) and carbon nanotubes (CNTs) to solve the above issues. Benefiting from the structural stability and superior conductivity in special 3D structure, the as-prepared NCS@GNs@CNTs electrode delivers a high initial discharge/charge capacity (558.1/538.8 mAh g1 at 100 mA g−1), superior cyclic stability (362.8 mAh g−1 after 100 cycles at 200 mA g−1) and an excellent rate capability (311.8 mAh g−1 at 5000 mA g−1). Furthermore, the sodium-ion full-cell Na3V2(PO4)3@C-NCS@GNs@CNTs test demonstrates that NCS@GNs@CNTs exhibits good cycling stability and further illustrates the possibility in practical applications.