High-Crystallinity Urchin-like VS₄ Anode for High-Performance Lithium-Ion Storage

Abstract

VS4 anode materials with controllable morphologies from hierarchical microflower, octopus-like structure, seagrass-like structure to urchin-like structure have been successfully synthesized by a facile solvothermal synthesis approach using different alcohols as solvents. Their structures and electrochemical properties with various morphologies are systematically investigated, and the structure–property relationship is established. Experimental results reveal that Li+ ion storage behavior in VS4 significantly depends on physical features such as the morphology, crystallite size, and specific surface area. According to this study, electrochemical performance degrades on the order of urchin-like VS4 > octopus-like VS4 > seagrass-like VS4 > flower-like VS4. Among them, urchin-like VS4 demonstrates the best electrochemical performance benefiting from its peculiar structure which possesses large surface area that accommodates the volume change to a certain extent, and single-crystal thorns that provide fast electron transportation. Kinetic parameters derived from EIS spectra and sweep-rate-dependent CV curves, such as charge-transfer resistances, Li+ ion apparent diffusion coefficients and stored charge ratio of capacitive and intercalation contributions, both support this claim well. In addition, the EIS measurement was conducted during the first discharge/charge process to study the solid electrolyte interface (SEI) formation on urchin-like VS4 and kinetics behavior of Li+ ion diffusion. A better fundamental understanding on Li+ storage behavior in VS4 is promoted, which is applicable to other vanadium-based materials as well. This study also provides invaluable guidance for morphology-controlled synthesis tailored for optimal electrochemical performance.

VS4‐Decorated Carbon Nanotubes for Lithium Storage with Pseudocapacitance Contribution

“…The two peaks at 2.0 and 1.67 Vare attributed to lithium insertion into VS 4 and conversion into Li x VS 4 , shiftings lightly to the negative potential region in the second and third cycles. [31,35] The weak peak at 0.71 Va rises from the formationo fasolid-electrolyte interphase (SEI) film and the furtherc onversion of Li x VS 4 into Li 2 Sa nd V, which disappears in the following cycles. [31,35] In the anodicp rofiles, two peaks are related to the delithiation conversion of Li 2 Si nto VS 4 and Li x VS 4 .T he second and third CV sweep show gave rise to almosti denticalp rofiles, showing the high reversibility of the lithiation-delithiation cycles for VS 4 /CNTs.…”

“…Vanadium sulfides, with attractive S–V–S layer structure and high electric conductivity, have recently been recognized as ideal host materials for Li + storage . To realize the high Li + storage performances of vanadium sulfides, fabricating specific nanostructures and compositing with carbon materials have been adopted.…”

“…[22] Vanadium sulfides, with attractive S-V-S layer structure and high electric conductivity,h ave recently been recognized as ideal host materials for Li + storage. [28][29][30][31][32][33][34][35] To realize the high Li + storagep erformances of vanadium sulfides, fabricating specific nanostructures and compositingw ith carbon materials have been adopted. Ac omputational study by Wang and co-workers predicted that VS 2 monolayer could obtain at heoretical capacity as higha s1 397 mAh g À1 for lithium ion storage,s uggesting the potentiala pplication for pseudocapacitive lithium storage.…”

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

“…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 .…”

“…However,p oorly defined bulk VS 4 undergoes severe pulverization and sluggish kineticsi nduced by the anisotropy in diffusion and the insufficient electrode-electrolyte contact,w hich lead to the poor cycling stabilitya nd rate capability. [14,23,24] Twoc ommon strategies for improving the electrochemicalp erformancesa re combining VS 4 with carbon nanomaterials [8,[18][19][20]25] and developing 3D self-assembled VS 4 nanoarchitectures. [7,14,15] Although the introductiono fc arbon nanomaterials can alleviate pulverization and promote electrochemical kinetics to some extent, the large surface area and volume increasethe side reactions and lower the energy density.…”