Room-temperature extraction of individual elements from charged spent LiFePO₄ batteries

Recycling millions of metric tons of spent LiFePO₄ batteries would benefit human health while reducing resource depletion and environmental pollution. However, recovering individual elements from the spent batteries without generating waste is challenging. Here, we present a distinctive approach for recycling spent LiFePO₄ batteries at room temperature, where water is the only leaching agent consumed. FePO₄ and lithium intercalated graphite act as a precursor material for selectively extracting lithium, iron, and phosphorus through charging the LiFePO₄ batteries to the delithiated state. NaOH solution extracted Fe from FePO₄ within 30 min and regenerated without consumption, similar to a catalyst. Under the optimal leaching conditions (1 mol·L⁻¹ NaOH, 0.5 h, NaOH/Fe molar ratio of 4.5), Fe and P leaching efficiencies achieved 89.1% and 99.2%, respectively. The methodology reflected in this research reduced the material cost per kg cathode material to a fraction of previously published reports, only occupies 6.13% of previous reports. In addition, the method improved the battery recycling revenue calculated by the EverBatt model by 2.31 times and 1.94 times over pyrometallurgical and hydrometallurgical methods. The proposed method allows for the convenient recovery of the elemental components of spent LiFePO₄ batteries.