Covalently binding ultrafine MoS2 particles to N, S co-doped carbon renders excellent Na storage performances

MoS2 has attracted much interest for the potential application in sodium-ion batteries (SIBs) anodes because of the high theoretical capacity and electrochemical activity with Na. However, poor electrochemical performance caused by severe volume variations during the charge/discharge processes limits its practical application. Herein, we present an elaborately designed architecture comprising ultrafine MoS2 nanoparticles covalently bonded to N, S co-doped carbon (MoS2/NSC) via an in situ solid-state growth process, which displays high-capacity Na storage, fast sodiation/desodiation kinetics, and substantially mitigated volume fluctuations. As a consequence, MoS2/NSC delivers outstanding Na storage performances including a high reversible capacity of 340 mA h g(-1) at 100 mA g(-1) and a rate capacity of 208 mA h g(-1) at 2000 mA g(-1). Further assembling with a Na3V2(PO4)(3)/C cathode, the full-cell delivers a specific capacity of 238 mA h g(-1) after 80 cycles at 50 mA g(-1), demonstrating the great potential of our MoS2/NSC electrode. Density function theory calculations manifest that NSC not only presents strong binding to MoS2 but also significantly decreases the Na ion diffusion energy barrier, thus leading to robust structure stability and fast electrode kinetics. This study may open a new and efficient avenue for developing advanced MoS2 anodes for SIBs. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study presents a carefully designed MoS2/NSC architecture that overcomes the issue of large volume fluctuations in MoS2 in sodium-ion batteries, demonstrating excellent sodium storage performance and kinetics, providing a new and efficient avenue for the development of MoS2 anodes in SIBs.