Recovery Of Waste Cathode Material Of Lithium Ion Battery Based On Organic Acid Leaching

With the wide application of lithium ion batteries,waste lithium-ion batteries are also increasing.The recovery of the waste lithium-ion batteries and cathode scrap are not only can solve the shortage of many resources,but also can reduce the threat to the environment and human health.Under the backgrand of recycling cathode materal in waste lithium ion battery,this paper makes a comprehensive analysis and evaluation about acid leaching process,studies the mechanism of leaching process,developes a recovery process of high purity lithium carbonate and high purity aluminum foil,finally simulates and calculates the dynamics on the leaching process.The main research contents are as follows:（1）In the sight of the problem that the research on the recovery of waste cathode scrap is very complex,the recovery process of lithium cobalt oxide was analyzed and evaluated comprehensively.It was found that the leaching rate of inorganic acid was stronger than that of organic acid,and all inorganic acids can react with Al completely,while the organic acids can be used to separate the aluminum foil from cathode material.The initial pH determines the initial leaching rate,and the total amount of H⁺in the solution determines the leaching rate of metals.（2）With the test methode of ICP-OES,XRD,XPS and others,the leaching solution and leaching residue（morphology,crystal form,element distribution,element valence state and so on）during the leaching process were analyzed.The particle size,surface and change of lithium cobalt oxide were identified.At the leaching time of 15min,the leaching rate of Co and Li reached to 100%,while the leaching rate of Al was less than 10%.There is no other valence state of Co³⁺in the leaching residue.（3）A recovery process of high purity lithium carbonate from the waste cathode material of lithium ion battery was developed.Under the best leaching condition,the leaching rate of Li and Al was 99.93%and 4.54%,the products are lithium carbonate and aluminum foil with the purity of 99.90%and 99.98%.Recovery of all the metals were higher than 95%.（4）By fitting the acid leaching process of lithium ion battery with a variety of kinetic model,formic acid leaching data of Ni,Co,Mn and Li in cathode scrap goes well with surface chemical reaction control model,the apparent activation energy of Co,Mn,Ni and Li with and without the addition of H₂O₂ are calculated respectively,indicating the fact that the addition of H₂O₂ can improve the leaching rate of reaction.