Highly Branched VS₄ Nanodendrites with 1D Atomic‐Chain Structure as a Promising Cathode Material for Long‐Cycling Magnesium Batteries

Abstract

Rechargeable magnesium batteries have attracted increasing attention due to the high theoretical volumetric capacities, dendrite formation-free characteristic and low cost of Mg metal anodes. However, the development of magnesium batteries is seriously hindered by the lack of capable cathode materials with long cycling life and fast solid-state diffusion kinetics for highly-polarized divalent Mg ions. Herein, vanadium tetrasulfide (VS ) with special one-dimensional atomic-chain structure is reported to be able to serve as a favorable cathode material for high-performance magnesium batteries. Through a surfactant-assisted solution-phase process, sea-urchin-like VS nanodendrites are controllably prepared. Benefiting from the chain-like crystalline structure of VS , the S dimers in the VS nanodendrites provide abundant sites for Mg insertion. Moreover, the VS atomic-chains bonded by weak van der Waals forces are beneficial to the diffusion kinetics of Mg ions inside the open channels of VS . Through a series of systematic ex situ characterizations and density functional theory calculations, the magnesiation/demagnesiation mechanism of VS are elucidated. The VS nanodendrites present remarkable performance for Mg storage among existing cathode materials, exhibiting a remarkable initial discharge capacity of 251 mAh g at 100 mA g and an impressive long-term cyclability at large current density of 500 mA g (74 mAh g after 800 cycles).

Enhanced Kinetics over VS4 Microspheres with Multidimensional Na+ Transfer Channels for High‐Rate Na‐Ion Battery Anodes

“…Among all of the reported anode materials for SIBs, V‐based sulfides have attracted attention owing to their high reversible capacities resulting from the large Na + storage spacing and the polytropic valence of V ranging from +5 to 0 . VS 4 , as a cheap and environmentally benign mineral (Patronite), is a potential electrode material for application in SIBs, owing to its unique structural characteristics of large interchain distance (5.83 Å) caused by parallel 1 D chains, weak interaction between neighboring chains caused by weak van der Waals forces, and high content of S − caused by S 2 2− monomer . These characteristics can not only afford enough potential sites for Na + storage with the theoretical specific capacity of 1196 mAh g −1 for VS 4 +8 Na + +8 e − ⇄4 Na 2 S+V, but also contribute to Na + transfer in the chains.…”

“…[5][6][7][8][9] VS 4 ,a sacheap and environmentally benign mineral (Patronite), is ap otential electrode materialf or application in SIBs, owing to its uniques tructural characteristics of large interchaind istance (5.83 )c aused by parallel 1D chains, weak interaction between neighboring chains caused by weak van der Waals forces, and high content of S À caused by S 2 2À monomer. [10][11][12][13][14] These characteristicsc an not only afford enough potential sites for Na + storagew ith the theoretical specific capacity of 1196 mAh g À1 for VS 4 + 8Na + + 8e À Q4Na 2 S + V, [8,10,15] but also contributet oN a + transfer in the chains.…”

“…In the past few years, VS 4 has been successfully applied to lithium‐ion batteries, SIBs, magnesium‐ion batteries, aluminum‐ion batteries, and supercapacitors, and its electrochemical performances as an anode material has been explored. However, poorly defined bulk VS 4 undergoes severe pulverization and sluggish kinetics induced by the anisotropy in diffusion and the insufficient electrode–electrolyte contact, which lead to the poor cycling stability and rate capability . Two common strategies for improving the electrochemical performances are combining VS 4 with carbon nanomaterials and developing 3 D self‐assembled VS 4 nanoarchitectures .…”

Vanadium‐Based Nanomaterials: A Promising Family for Emerging Metal‐Ion Batteries

“…Very recently, the application of VS 4 as cathode for MIBs was also reported . The sea‐urchin‐like VS 4 nanodendrites (Figure b) were prepared through a solution‐phase process, which exhibits reversible Mg 2+ storage capacity of 137 mAh g −1 at 50 mA g −1 and 106 mAh g −1 at 500 mA g −1 (Figure c).…”

“…d) The illustration of the Mg 2+ storage process of VS 4 . Reproduced with permission . Copyright 2018, Wiley‐VCH.…”