Ni₃S₄/SnS/Graphene Oxide/Carbon Nanotube Composites as Anodes for Na-Ion Batteries

Abstract

To boost the electrochemical kinetics of sodium-ion batteries (SIBs), scheming of nanocomposite materials and apprehending the synergistic effect between synthesized constituents are rationally vital. Due to high performance and superior theoretical capacity, transition-metal sulfides appear prominent anode applicants for SIBs. Still, constraints exist in their practical usage due to structural damage, leading to poor cycling stability, severe capacity loss, and low rate performance. In this study, an integrated amalgam of Ni3S4/SnS (NTS) heteroarchitecture has been fabricated with reduced graphene oxide (NTS-rGO) and carbon nanotubes (NTS-CNTs) via a scalable and green hydrothermal route. In the successive hydrothermal treatment, the sulfur ions released from sodium sulfide react with nickel and tin ions to produce NTS heterostructure and provide a synergistic effect. The morphology displays nucleation of multiple nanoseeds, which grows into nanosheets of NTS for which rGO behaves as a template growth and CNT mesh befits the bridge to link the heterostructure of NTS. For NTS-rGO and NTS-CNTs NCs, the initial charge capacity was measured as 402 and 447 mA h g–1 at a rate of 0.05 C, respectively. Furthermore, CNTs act as a passivation layer and can accommodate structural integrity and prevent nanoparticles from aggregation during prolonged cycling; hence, NTS-CNTs displays ultra-cycling stability with a Coulombic efficiency of 100%, illuminating the synergistic effect among NTS and CNT unique patterns. The charge-transfer resistance is noticed to be the lowest for hybrid heterostructural NTS-CNTs (403.2 Ω) as compared to NTS-rGO and pure NTS (526.7 and 605.9 Ω), which effectively increase the charge transportation. The transition between diffusion and capacitive currents validates that charge storage is mainly pseudocapacitive at elevated scan rates in NTS-CNTs anode which is driven by finding of swift Na ion diffusion and rapid near-surface Na storage compared to pure NTS and NTS-rGO.

Tuning kinetics of SnS/Ni3S4 binary sulfides for high rate and long cyclic lithium-ion batteries

“…[42][43][44][45][46][47] Although, tin and nickel based binary sulfides combined with supporting materials such as GO, rGO, carbon cloth, CNTs and Ni-foam have been extensively investigated for energy storage but pure tin and nickel based binary systems are scarcely explored. [48][49][50][51][52] In this paper, we report hierarchical flower-like novel SnS/Ni 3 S 4 binary sulfides with tuned morphology and chemical composition via a facile hydrothermal approach. The optimized binary sulfide (SN-2) as an anode exhibits high specific capacity, excellent cyclic stability and high rate capability without rapid capacity fading.…”

Small PbS Nanocubes Embedded in Carbon Shells for Na Storage

“…In most of the current literature stuides, MS x is achieved by hydrothermal treatment or high-temperature vulcanization. − Consequently, in order to construct carbon/MS x composites, it is common to synthesize the MS x followed by carbon coating, or to prepare the carbon material first and then anchor the MS x on the carbon surface. − These methods easily generate large-size MS x crystals, which would lengthen Na + diffusion distance and cause severe volume changes during the sodiation/desodiation process, resulting in limited structural stability and Na + storage performance. − Therefore, it is urgent and challenging to develop new methods to synthesize carbon/MS x composites with ultrafine MS x crystals and superior electrochemical performance.…”