V3S4 Nanosheets Anchored on N, S Co-Doped Graphene with Pseudocapacitive Effect for Fast and Durable Lithium Storage.

Wu Wu,Zhou Zhou,Miao Miao,Liu Liu,Guo Guo,Zhang Zhang

doi:10.3390/nano9111638

Abstract

Construction of a suitable hybrid structure has been considered an important approach to address the defects of metal sulfide anode materials. V3S4 nanosheets anchored on an N, S co-coped graphene (VS/NSG) aerogel were successfully fabricated by an efficient self-assembled strategy. During the heat treatment process, decomposition, sulfuration and N, S co-doping occurred. This hybrid structure was not only endowed with an enhanced capability to buffer the volume expansion, but also improved electron conductivity as a result of the conductive network that had been constructed. The dominating pseudocapacitive contribution (57.78% at 1 mV s−1) enhanced the electrochemical performance effectively. When serving as anode material for lithium ion batteries, VS/NSG exhibits excellent lithium storage properties, including high rate capacity (480 and 330 mAh g−1 at 5 and 10 A g−1, respectively) and stable cyclic performance (692 mAh g−1 after 400 cycles at 2 A g−1).

Highlights

Lithium ion batteries (LIBs) are the dominant energy storage device in the field of mobile devices
According to the above works, VS4 microsphere@PANI delivered a capacity of 755 mAh g−1 at the 50th cycle under a current density of 0.1 A g−1 [11], and the VS4/graphene composite exhibited a capacity of 954 mAh g−1 at the end of 100 cycles under the same current density [18]
When serving as an anode material for LIBs, V3S4 nanosheet anchored on N, S-doped graphene exhibits a high rate capacity (480 and 330 mAh g−1 at 5 and 10 A g−1, respectively) and stable cyclic performance at high rate (692 mAh g−1 after 400 cycles at 2 A g−1)

Summary

Introduction

Lithium ion batteries (LIBs) are the dominant energy storage device in the field of mobile devices. Traditional graphite anodes, on the other hand, could not meet the above requirements Numerous novel candidates, such as transition metal oxide, sulfide, alloy, and silicon, have been explored to replace the commercial graphite anode material. Among these anode materials, the earth-abundant and high capacity and transition of multiple valence vanadium-based materials are considered as the most promising candidate for the advanced LIBs [2]. Bulk metal sulfides usually suffer from large volumetric expansion (resulting in the obvious capacity fading) and sluggish electron transport kinetics (the cause of the inferior rate property) [8,9]. The green synthesis route is still a challenge for the application of vanadium sulfides anode materials

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Results

Conclusion