Transforming Undesired Corrosion Products into a Nanoflake-Array Functional Layer: A Gelatin-Assistant Modification Strategy for High Performance Zn Battery Anodes.

As corrosion products of Zn anodes in ZnSO electrolytes, ZnSO (OH)·xHO with loose structure cannot suppress persistent side reactions but can increase the electrode polarization and induce dendrite growth, hindering the practical applications of Zn metal batteries. In this work, a functional layer is built on the Zn anode by a gelatin-assistant corrosion and low-temperature pyrolysis method. With the assistant of gelatin, undesired corrosion products are converted into a uniform nanoflake array comprising ZnO coated by gelatin-derived carbon on Zn foil (denoted Zn@ZnO@GC). It is revealed that the gelatin-derived carbons not only enhance the electron conductivity, facilitate Zn desolvation, and boost transport/deposition kinetics, but also inhibit the occurrence of hydrogen evolution and corrosion reactions on the zincophilic Zn@ZnO@GC anode. Moreover, the 3D nanoflake array effectively homogenizes the current density and Zn concentration, thus inhibiting the formation of dendrites. The symmetric cells using the Zn@ZnO@GC anodes exhibit superior cycling performance (over 7000 h at 1 mA cm/1 mAh cm) and without short-circuiting even up to 25 mAh cm. The Zn@ZnO@GC||NaVO full cell works stably for 5000 cycles even with a limited N/P ratio of ≈5.5, showing good application prospects.