An enhanced kinetics and ultra-stable zinc electrode by functionalized boron nitride intermediate layer engineering

Abstract

The current application of zinc (Zn) anode for aqueous Zn-ion batteries (AZIBs) is faced with several challenges, such as the Zn dendrite growth, hydrogen evolution reaction and by-product generation. Here, an intermediate layer of sulfonate group modified boron nitride nanosheets (S-BN) has been rationally designed and harnessed to regulate Zn plating/stripping behavior and mitigate the side reaction with electrolyte. Benefiting from the nanoscale cavities and surface anionic charge groups, the S-BN intermediate layer endows a dendrite-free electrodeposition behavior via an advanced desolvation process and even interface electronic field. As expected, the S-BN@Zn symmetrical cell enables long-term cycling of 2500 h under 2 mAh·cm−2 with a small plating/stripping overpotential of around 45 mV. When coupled with Na2V6O16·1.63H2O (NVO) cathode, the S-BN@Zn/NVO battery can operate stably up to 1200 cycles, implying the superior durability of S-BN@Zn anode. Accordingly, this novel Zn diffusion intermediate layer provides a promising approach to significantly enhance the anode electrochemical performance of AZIBs.