Complexation chemistry as a corrosion control of aluminum anode in neutral aluminum-based electrochemical energy systems
- Journal
- Energy Storage Materials
- Page
- 104540
- Year
- 2025
- Link
- https://doi.org/10.1016/j.ensm.2025.104540 171회 연결
Abstract
Aluminum-based electrochemical energy systems (Al-EES) are emerging as promising next-generation energy storage platforms due to aluminum’s high theoretical capacity, low cost, and environmental abundance. However, performance in neutral electrolytes is often constrained by AlCl3 gelation, pitting corrosion, and sluggish cathodic kinetics. To overcome these challenges, we introduce a membrane-assisted neutral Al-EES featuring a sodium-ion (Na+) conducting membrane, sodium chloride (NaCl) as anolyte, sodium persulfate (Na2S2O8) as catholyte, and tannic acid (TA) as a multifunctional corrosion inhibitor. The Na+ conducting membrane effectively separates anodic and cathodic compartments while suppressing chlorine evolution and stabilizing the redox environment. TA forms chelated complexes with Al3+ and adsorbs on the Al surface, reducing corrosion and promoting uniform anodic dissolution. Electrochemical techniques including EIS, PDP, and in-situ SECM confirm improved charge transfer and interfacial stability. The optimized Al-EES delivers a specific capacity of 2600 Ah/kgAl, energy density of 3152 Wh/kgAₗ, and a stable voltage of ∼1.65 V. It achieves a four-fold power increase over conventional Al-air batteries, sustaining 120 h of continuous operation and over 630 h of intermittent discharge the first >500-hour demonstration in a neutral Al-based electrochemical energy system. This work offers a corrosion-resistant, catalyst-free, and scalable approach to an Al-based energy system.