Recovery And Reuse Of Li?Co,Ni,Mn?O₂ Cathode Material In Waste Lithium Ion Battery

There are many metal resources?e.g.Co,Ni,Mn,Al?in lithium ion batteries,and some toxic chemicals,such as fluoride.Therefore,it is very important to recycle and reuse of the waste lithium-ion power battery especially the cathode material for save natural resources and protect the environment.However,there is little atention on the research of which at present.Above that questions,this paper pursues research on the waste lithium ion power battery with Li?Ni,Co,Mn?O₂?hereinafter referred to as "NCM"?.The main contents of this paper are summarized as follows:?1?We assess the electrochemical performance?residual capacity,internal resistance,voltage,etc.?of the spent NCM lithium ion battery and compared with the same series of new lithium ion batteries.And then,determine whether these batteries have been unable to meet the high performance of the electrical equipment.?2?we disassemble these batteries which have been unable to meet the application of high-performance electric equipment by manual to recycle.First of all,in order to ensure the complete discharge of waste batteries,designning several experiments to compare and get the best concentration of NaCl solution,which makes the battery short circuit and complete discharge.Then,the waste batteries are disassembled,as well as the positive pole/negative pole and separators are separated.After separation,the cathode active material and the aluminum foil were separated by organic solvent?1-methyl-2-pyrrolidone,referred to as "NMP"?,and we research on the effects of different solid/liquid ratio,soaking temperature and time on the separation of positive active material and aluminum foil.Subsequently,the recovered material is calcined at different temperatures.To determine whether the organic matter such as impurity carbon and binder?vinylidene fluoride,referred to as "PVDF"?is completely removed,we use X-ray powder diffraction?XRD?,scanning electron microscopy?SEM?,infrared spectroscopy?FT-IR?and thermogravimetric analysis?TGA?.Finally,the dopant material is assembled into a coin cell for its electrochemical performance.?3?Using the NCM material which is calcined as raw material,there are two ways to synthesis of the new NCM material to improve the specific capacity of recycled materials.The first is the coprecipitation method,according to theinductively coupled plasma?ICP?to test the metal content of the recovered material,using citric acid as the leaching agent and complexing agent to synthesize the target product.And the dissolution rate of the recovered material is studied from the five aspects,such as: citric acid concentration,the amount of hydrogen peroxide added,the ratio of liquid to liquid,the temperature of water bath and the time of magnetic stirring.The second is the high-temperature solid-phase method,by adding the lithium material directly in the recovery of high-temperature roasting synthesis of the target product.The materials are synthesized by adding different materials with different quality than lithium source,and characterized by XRD and SEM.Finally,the material assembles into a button battery charge and discharge test to determine the best adding lithium source quality ratio.