Chromate conversion coated aluminium as a light-weight and corrosion-resistant current collector for aqueous lithium-ion batteries

Abstract

Aqueous batteries constructed using non-flammable water-based electrolytes have the potential to improve the safety and reduce the cost of energy storage to enable mass adoption of electric vehicles. The use of low-cost and lightweight aluminium foil as a current collector in aqueous batteries is tempting but also challenging due to corrosion reactions. Here we report chromate conversion coated (CCC) aluminium foil as a corrosion-resistant current collector in aqueous lithium-ion battery cathodes. CCC aluminium-based electrodes show better cycling stability and higher coulombic efficiency than those fabricated on stainless steel and titanium foils. Furthermore, CCC aluminium foil suppresses oxygen evolution at high potentials. The plausibility of using such lightweight corrosion-resistant current collectors for aqueous batteries marks an important step toward low-cost, high-energy, and safe energy storage.