Novel Application of Repaired LiFePO4 as a Candidate Anode Material for Advanced Alkaline Rechargeable Batteries

The extensive application of LiFePO4 batteries for energy storage in recent years will result in a large number of spent LiFePO4 batteries in the future. How to properly recycle these spent LiFePO4 batteries becomes an extremely thorny subject. Here, a sustainable and facile strategy has been developed to regenerate LiFePO4 materials as novel anode materials for alkaline secondary batteries. For the first time, it has been interestingly found that the repaired LiFePO4 anode with Bi2S3 additive in alkaline solutions can deliver prominent anodic performance, with a high specific capacity of similar to 242.2 mAh g(-1) at 50 mA g(-1) (showing a charge efficiency of similar to 88.1%), excellent high-rate performance (173.6 mAh g(-1) still retains even at 1250 mA g(-1)), and good cycling life (capacity retention of similar to 97.5% after 100 cycles at 50 mA g(-1)). It is first discovered that alkaline LiFePO4 anode goes through a dissolution-deposition process during the charge-discharge process. Furthermore, a unique alkaline Ni(OH)(2)/LiFePO4 battery system is successfully established by adopting the recovered LiFePO4 materials and Ni(OH)(2) cathodes. The assembled full battery with a commercial electrode loading lever of similar to 30 mg cm(-2) can deliver both high specific energy and power densities, which is comparable with commercial Ni/Fe batteries. This work not only proposes an attractive route to recycle spent LiFePO4 of lithium-ion batteries in large scale but also offers an economical way to produce sustainable anodes for Ni/Fe batteries.