Low‐Cost Multi‐Function Electrolyte Additive Enabling Highly Stable Interfacial Chemical Environment for Highly Reversible Aqueous Zinc Ion Batteries

Abstract The practicality of aqueous zinc ion batteries (AZIBs) for large‐scale energy storage is hindered by challenges associated with zinc anodes. In this study, a low‐cost and multi‐function electrolyte additive, cetyltrimethyl ammonium bromide (CTAB), is presented to address these issues. CTAB adsorbs onto the zinc anode surface, regulating Zn 2+ deposition orientation and inhibiting dendrite formation. It also modifies the solvation structure of Zn 2+ to reduce water reactivity and minimize side reactions. Additionally, CTAB optimizes key physicochemical parameters of the electrolyte, enhancing the stability of the electrode/electrolyte interface and promoting reversibility in AZIBs. Theoretical simulations combined with operando synchrotron radiation‐based in situ Fourier transform infrared spectra and in situ electrochemical impedance spectra further confirm the modified Zn 2+ coordination environment and the adsorption effect of CTAB cations at the anode/electrolyte interface. As a result, the assembled Zn‐MnO 2 battery demonstrates a remarkable specific capacity of 126.56 mAh g −1 at a high current density of 4 A g −1 after 1000 cycles. This work highlights the potential of CTAB as a promising solution for improving the performance and practicality of AZIBs for large‐scale energy storage applications.