A self-repairing polymer-inorganic composite coating to enable high-performance Zn anodes for zinc-ion batteries

There are some critical issues hindering the practical applications of aqueous zinc-ion batteries(zIBs),although they possess high safety and low cost as one of promising energy storge devices,such as the Zn dendrite growth and the by-product of Zn_(4)SO_(4)(OH)_(6)-xH_(2)O(ZHS)resulted from some side reactions in a mild electrolyte.Herein,a compact and self-repairing solid electrolyte interface(SEl)film,as labeled the PVDF-Zn(TFSI)_(2)-ZHS coating[The PVDF and Zn(TFSI)_(2)are polyvinylidene fluoride and zinc bis(trifluoromethanesulfonyl)imide,respectively],which turns the in-situ generated ZHS into a beneficial ingredient onto the pre-coated PVDF-based composite coating layer containing Zn(TFSI)_(2),was designed and fabricated by a simple doctor blade method.It is shown that the SEl layer can effectively isolate Zn from the electrolyte and homogenize the Zn^(2+)flux,and thus effectively suppress side reactions and dendrites growth.Benefiting from the hybrid SEl layer,a symmetric cell exhibits a high cycling stability over 750h at 2.0 mA/cm^(2)and 2.0 mAh/cm^(2),and meanwhile,a full-cell,coupled with K^(+) pre-intercalationα-MnO_(2)(KMO)cathode,displays excellent rate performance,stable coulombic efficiency and an acceptable cycle life.This work provides a feasible approach for simple and scalable modification of Zn anodes to achieve high performance.