Recycling Processing For Scrap LiFePO₄ Battery And Study On Regeneration Of Scrap Cathode Material

The using of LiFePO₄ batteries has been increasing because of its high energy density,good safety performance,no memory effect,long service life,etc.So it can be predicted that there will be a lot of scrap Li-ion power batteries in the near future.If these scrap Li-ion power batteries are not handled properly,it will resulte in a huge waste of resources and the pollution of the environment.Now,the recycling technologies of waste Li-ion battery mainly include mechanical separation process,heat treatment process,mechanical chemical process,dissolving process,chemical precipitation process,electrochemical process and extraction process,etc.But these processes still bring complex operation,high cost,the pollution of the environment,etc.And most of the processes apply to the batteries containing Ni,Co and other precious metals,rather than apply to LiFePO₄ batteries.In this paper,a recycling technology of scrap square LiFePO₄ power battery was designed and the directly regenerated with Li₂CO₃ of scrap cathode material was studied.For one thing,a dismantling separation device was designed and the experimental equipments include discharge device,soaking,electrodes separation and shearing device,current collector and electrode material separation device,screening device,waste gas purification device.A technology of recycling scrap square LiFePO₄ power battery was also designed.It mainly contains batteries discharge,dismantling batteries,soaking cell,cathodes separation,shearing electrodes,stirring cathodes,centrifugal waste materials,drying waste materials,ball-milling waste materials,screening waste materials and waste gas purification.By this process,the scrap cathode material,scrap anode material and other by-products?shell,Al foil,Cu foil and electrolyte solvent,etc.?are recycled efficiently.This technology achieves safe,green recycling of the scrap square LiFePO₄ power battery.For another,the directly regenerated with Li₂CO₃ of scrap cathode material was studied further.In addition to LiFePO₄ and acetylene black,there were some parts of LiFePO₄ decomposition products,such as FePO4 and P2O5.Direct regeneration procedure of scrap cathode material from 600 to 800 °C is investigated detailly.These results revealed that the cathode material displays complete crystal structure,uniform particle size,high particle size and tap density,good electrochemical performance.Especially,cathode material regenerated at 650 °C displays excellent physical,chemical and electrochemical performances,which up to the reuse requirement for Li-ion batteries.The results indicated that the green direct regeneration process with low-cost and high added-value is feasible.