2D VS₂ @MXene Based Zinc Ion Batteries with SPANI-Contained Electrolyte Enables Dendrite-Free Anode for Stable...

Regarded as one of the popular cathode materials in aqueous zinc ion batteries (ZIBs), VS₂ has unsatisfied cycling stability and relatively low capacity owing to its poor conductivity and low mechanical properties. To this regard, compositing VS₂ with high-conductive 2D transition metal carbide (MXene) has been an effective method recently. However, the Zn dendrite on the anode electrode derived from the uncontrollable sluggish migration of solvated Zn²⁺ /H₂ O ions seriously threatens the application safety of ZIB batteries. To effectively regulate the diffusion of zinc ions, in this work a conductive polymeric electrolyte of sulfonated polyaniline (SPANI) is added in the electrolyte solution. Under the Zn²⁺ /SPANI interactions confirmed by X-ray diffraction, Raman, and zeta potential experiments, the Zn²⁺ /H₂ O combination is weakened, and the deposition rate of Zn²⁺ is increased evaluated by the galvanostatic intermittent titration technique. Theoretical simulation shows that the electrostatic shielding by SPANI combining Zn^2- at the zinc/electrolyte interface has important contribution to the significant suppression of Zn dendrite. Accordingly, the fabricated VS₂ @MXene||ZnSO₄ +SPANI||Zn battery shows high capacity (368.0 mAh g^-1 at 0.1 A g^-1 ), which remains 96% after 5000 cyclic charge-discharge operations. This work develops an available strategic idea for suppressing growth of metallic dendrites to improve the ZIB performances.