ZnSe⊂MoSe2/rGO Petal-like Assembly as Fast and Stable Sodium Ion Storage Anodes

Abstract

The development of high energy and power density sodium-ion batteries (SIBs) has attracted increasing interest in the last two decades due to the abundance and cost-effectiveness of sodium resources. Herein, this study developed a self-templating synthetic method to construct MoSe2 nanosheets which were intercalated by ZnSe nanoparticles and were anchored on the in situ reduced graphene oxide layers. The thus-fabricated composites exhibited excellent Coulombic efficiency, a remarkable rate capability and an exceptionally long cycle life when being utilized as the anode in SIBs. Specifically, a reversible capacity of 265 mAh g−1 was achieved at 20 A g−1, which could be maintained for 6400 cycles. At an ultra-high rate of 30.0 A g−1, the anode retained a capacity of 235 mAh g−1 after 9500 cycles. Such a strong performance was attributed to its unique porous structure and synergistic interactions of multi-components. The underlying sodium storage mechanism was further investigated through various techniques such as in situ X-ray diffraction spectroscopy, the galvanostatic intermittent titration method, etc. Overall, this study illustrates the great potential of clad-structured multicomponent hybrids in developing high-performance SIBs.