Biomimetic Inorganic–Organic Protective Layer for Highly Stable and Reversible Zn Anodes

Uncontrollable dendrite growth and severe parasitic side reactions on Zn electrodes pose formidable challenges for the application of aqueous Zn-ion batteries. Herein, we engineered a biomimetic inorganic–organic protective layer composed of alginic acid and lithium magnesium silicate to enhance the stability and reversibility of the Zn electrode. This protective layer not only diminishes free water concentration near Zn surface but also creates negatively charged ion microchannels to transport Zn ions and modulate the solvation structure. Moreover, a robust Mg-SiO2 interphase with high Young's modulus and strong zincophilicity can be formed between the Zn electrode and the protective layer, facilitating uniform Zn deposition along Zn(002) planes. Consequently, this protective layer allows the Zn electrodes to achieve impressive cycling lifespan of 5500 h at 1 mA cm–2/1 mAh cm–2 with a Coulombic efficiency of 99.5% and delivers a remarkable cyclability of up to 8000 cycles in Zn||V2O5 full cells.