Adjust the pH Value of the Electrolyte to Improve the Performance of Aqueous Zinc‐Ion Batteries by Using Citric Acid Additives

Aqueous zinc‑ion batteries (AZIBs) are regarded as the next generation of promising energy storage system. Their advantages include low cost, high safety, and environmental friendliness. However, problems such as hydrogen evolution reaction (HER), dendrite growth, and zinc anode corrosion seriously limit their cycle stability and reversibility. In this research, citric acid (CA) was added as a multifunctional additive to the traditional ZnSO ₄ electrolyte to systematically investigate its improvement effect and mechanism on the performance of AZIBs. Through electrochemical testing and material characterization, it was found that the coordination interaction between CA and Zn ²⁺ could promote uniform nucleation, inhibit dendrite growth. And under specific conditions, the Zn//Zn symmetric cell can achieve stable cycling for nearly 1000 h, while also inhibiting the generation of by‐products. The full cell test using the self‐made sodium‐doped V ₂ O ₅ as the positive electrode and Zn as the negative electrode showed that the electrolyte containing CA additive made the oxidation–reduction voltage of the cell slightly lower at different sweep rates, and the discharge capacity was higher at different current densities, with better electrode electrochemical performance. This study provides new ideas for the development of low‐cost and eco‐friendly electrolyte additives.