Achieving stable zinc metal anode through interfacial regulation enabled by shikimic acid additive

Aqueous zinc ion batteries (AZIBs) have been widely studied due to their advantages of high energy density, safety and economy. However, the growth of dendrites and spontaneous side reactions on the Zn anode limit the practical application of AZIBs. Here, low-cost shikimic acid (SA) is used as an electrolyte additive to adjust the Zn²⁺ deposition process. The experimental results and theoretical calculations show that when SA molecules are added to the electrolyte, the structure of the electric double layer can be reshaped to optimize the electrode reaction interface. In addition, SA molecules can adsorb on the surface of Zn anode and thus inhibit the generation of zinc dendrites by increasing the exposure of (002) crystal plane during cycling, which effectively prolongs the cycle life of Zn anode. The Zn//Cu asymmetrical cell achieves an average coulombic efficiency of 99.57 % in an electrolyte containing 5 g L^-1 SA, and runs for more than 800 cycles at 10 mA cm^-2 and 2 mAh cm^-2. The Zn//Zn symmetrical cell can run stably for more than 1300 h at 2 mA cm^-2, 2 mAh cm^-2, and the capacity of Zn//MnO₂ full cell can be maintained at 107.3 mAh g^-1 after 500 cycles at 1 A g^-1.