Localized electric field enabling rapid and quasi-dry recycling of cathode active materials at ambient condition

Abstract

Amidst the increasing use of Li-ion batteries for power and energy storage, urgent attention is needed for effective recycling to address material supply and environmental concerns. Traditional pyro- and hydro-metallurgical methods, known for destructiveness and high energy consumption, are particularly problematic for widely used cathodes like LiFePO₄. Here, we introduce a rapid (<1 s) and quasi-dry method for recycling active cathode materials at ambient conditions, minimizing energy and water consumption. Applying an electrical field (∼20 V) to wetted LiFePO₄ films (∼80 μm vs LFP layer) produces a robust localized field (∼10⁵ V/m) that drives instantaneous local water splitting at Al foil interfaces, generating H₂ bubbles and facilitating efficient cathode material separation. Mild conditions and an ultra-short reaction time not only minimize the impact on cathode materials (>20X less Al impurities and negligible structural damage) but also streamline regeneration, potentially maintaining the electrochemical performance of LiFePO₄ scrap comparable to commercial counterparts without the need for regeneration. Comparative analysis with traditional pyro and hydro methods highlights our approach's superior energy efficiency, minimal wastewater emission, and increased profitability, offering a versatile strategy for various cathode chemistries and continuous roll-to-roll recycling of battery scraps.