Work

Synchronous regulation of V2O5 cathode and Zn anode using sodium gluconate as an additive for long-life aqueous zinc-ion batteries

Year: 2024

Type: article

Abstract: Aqueous zinc-ion batteries (AZIBs) are gaining attention owing to their affordability, high safety, and high energy density, making them a promising solution for large-scale energy storage. However, their performance is hampered by the instability of both the anode–electrolyte interface and the cathode–electrolyte interface. The use of sodium gluconate (SG), an organic sodium salt with multiple hydroxyl groups, as an electrolyte additive is suggested. Experimental and theoretical analyses demonstrate that Na+ from SG can intercalate and deintercalate within the associated V2O5 cathode during insitu electrochemical processes. This action supports the layered structure of V2O5, prevents structural collapse and phase transitions, and enhances Zn2+ diffusion kinetics. Additionally, the gluconate anion disrupts the original Zn2+ solvation structure, mitigates water-induced side reactions, and suppresses Zn dendrite growth. The synchronous regulation of both the V2O5 cathode and Zn anode by the SG additive leads to considerably performance improvements. Zn||Zn symmetric batteries demonstrate a cycle life exceeding 2,800 h at 0.5 mA cm−2 and 1 mAh cm−2. In Zn||V2O5 full batteries, a high specific capacity of 288.92 mAh g−1 and 82.29% capacity retention are maintained over 1,000 cycles at a current density of 2 A g−1. This multifunctional additive strategy offers a new pathway for the practical application of AZIBs.

Source: Journal of Energy Chemistry

DOI: 10.1016/j.jechem.2024.12.032