Interfacial engineering with BN@cellulose separator to suppress dendrite growth and side reactions in aqueous zinc-ion batteries

The lifespan of aqueous zinc-ion batteries, which are promising alternatives to Li-ion batteries, is affected by the irreversibility of Zn anodes, primarily caused by Zn dendrite growth and side reactions such as hydrogen evolution and corrosion during cycling. This study introduces a strategy to regulate zinc ion flux between the Zn anode and aqueous electrolyte by coating boron nitride (BN) onto a cellulose separator using a simple doctor blade method. The resulting BN@cellulose separator effectively suppresses Zn dendrite growth and minimizes side reactions in aqueous electrolytes. Electrochemical evaluations demonstrate that the BN coating reduces interfacial corrosion and enhances electrochemical stability compared to a bare cellulose separator by regulating the zinc ion flux between the electrolyte and active Zn sites. Overall, use of the BN@cellulose separator improved the electrochemical performance and prolonged cycling stability. The proposed strategy marks a significant advancement toward enhancing the long-term reliability of aqueous zinc-ion batteries.