Double-layer carbon protected CoS₂ nanoparticles as an advanced anode for sodium-ion batteries

Abstract

The outstanding electrochemical performance is ascribed to the novel structure design of CoS2@GC@B-CNT.

Dual coating strategy of CoS2@Co@C toward fast insertion/extraction anode material for sodium‐ion batteries

“…Figure 4 demonstrates the CV of the two cycles of CoS 2 @Co@C electrode from 0.01 V to 3.0 V potential range. During 1st cathodic process, five reduction peaks are noticed at the potential of 2.12, 1.34, 0.91, 0.58, and 0.15 V. These peaks belong to the step‐wise reduction of Co and formation of Na x S species (CoS 2 + 4Na + → Co 0 + 2Na 2 S) 28 . Five oxidation peaks at 0.82, 1.16, 1.68, 2.03, and 2.79 V were observed during 1 st anodic process.…”

“…Co 0 + 2Na 2 S). 28 Five oxidation peaks at 0.82, 1.16, 1.68, 2.03, and 2.79 V were observed during 1 st anodic process. These oxidation peaks indicate the conversion of Na x S and the reverse formation of CoS 2 .…”

“…Yao et al reported double‐layer graphitic carbon and nanotubes coating on CoS 2 which resulted in high electrochemical performance with durable cycling of 900 cycles. Stability of anode was attributed to the enhanced electrical conductivity due to double coating which also prevented the agglomeration of particles during charge/discharge process 28 . Liao et al reported CoS 2 nanoparticles on the reduced graphene sheets which resulted in stable cycling up to 50 cyclesbut high rate capability test was influenced by the sluggish kinetics of sodium ions 29 .…”

“…Stability of anode was attributed to the enhanced electrical conductivity due to double coating which also prevented the agglomeration of particles during charge/discharge process. 28 Liao et al reported CoS 2 nanoparticles on the reduced graphene sheets which resulted in stable cycling up to 50 cyclesbut high rate capability test was influenced by the sluggish kinetics of sodium ions. 29 Until now, different strategies based on composites are disclosed to increase the battery performance of CoS 2 but it still requires attention to overcome the presented challenges.…”