Cost effective synthesis hetero-structured N-doped C-coated Ni9S8/Ni3S2/NiS1.03 nanoparticles attached on 3D reduced graphene oxide anode to exceptional Li-ion performance

In this study, nitrogen all-doped carbon-coated Ni9S8/Ni3S2/NiS1.03 (NixSy) particles with homogeneous bonds to 3D reduced graphene oxide sheets (N-NixSy@C/G) were synthesized via a using the facile hydrothermal, freeze-drying and subsequent calcination method. In this structure, the carbon layer derived from glucose was highly uniformly dispersed in an Ar atmosphere, such that the structural stability is enhanced and the volume expansion of NixSy is effectively mitigated. The Ni9S8, Ni3S2 and NiS1.03 nanoparticles were formed effectively facilitated under the existence of glucose. In situ nitrogen doping was achieved by the presence of urea containing nitrogen, such as electron conductivity was increased and fast ion intercalation was facilitated. The structural stability and cyclability can be ensured for the high flexibility and structural strength of the reduced graphene oxide wrapping layer. Under the synergistic effect exerted by the three modules, N-NixSy@C/G was further endowed with high electrical conductivity, large specific surface area as well as abundant electrochemical reaction sites. On that basis, the N-NixSy@C/G anode that was employed in the lithium-ion batteries exhibited superior rate capability and ultra-high reversible capacity (826.3 mAh g−1 at 0.5 A g−1). The capacity was kept at 703 mAh g−1 and the coulombic efficiency reached 100% after 1000 cycles at a current density of 2 A g−1. This study may contribute to the creation of a distinctive avenue for designing quick and high-capacity metal sulfide anodes and boost the growth of high-performance lithium batteries.