Facile and efficient regeneration of LiFePO4 battery cathode using a multifunctional lithium source

Abstract

Lithium iron phosphate (LFP) batteries are widely used in energy vehicles and electrochemical energy storage due to their high safety and long cycle life. However, the disposal of large quantities of spent LFP batteries has become a practical challenge, as improper handling may lead to resource waste and environmental pollution. Herein, we propose a facile and efficient approach to directly regenerate waste LFP cathodes using a multifunctional lithium source (CMCLi) through high-temperature calcination. CMCLi not only supplies Li+ to fill lattice vacancies in the degraded LFP structure but also forms a carbon coating that encapsulates the LFP particles. This coating establishes a reducing atmosphere to convert Fe3+ to Fe2+, enhances electronic conductivity, and inhibits particle aggregation and pulverization during cycling. As a result, the degraded LFP material is effectively restored. The regenerated LFP cathode exhibits satisfactory electrochemical performance, including a high discharge capacity (145.5 mA h g−1 at 0.2 C) and stable cycling behavior. This work offers an economical and energy-efficient strategy for direct regeneration of LFP cathodes, paving the way for sustainable development of LFP-based energy storage.