Study On Resource Recovery Behavior Of Spent Lithium Iron Power Battery By Tributyl Phosphate

As the main assembled battery for new energy vehicles,the scrap of lithium iron phosphate battery has been increasing with the vigorous development of the new energy automobile industry.The lithium iron phosphate battery contains rare light metal lithium,which has important resource regeneration value.At present,there are few reports on the recovery of lithium in the spent lithium iron phosphate batteries,and there are many problems in the regeneration process,such as impurity ions in regenerated lithium?or lithium compounds?,and the recovery rate is low.In this paper,solvent extraction method is adopted as the main technical means for lithium regeneration and recovery in spent lithium iron phosphate battery,the main factors and control factors for the efficient extraction of lithium ion with tributyl phosphate were analyzed by simulation experiments,the suitable conditions for the extraction and separation of lithium from the tributyl phosphate and the transfer behavior of lithium and iron were studied in-depth.The mechanism of selective extraction of lithium by tributyl phosphate was investigated by means of Raman spectroscopy,related research results can provide an important reference for the efficient reference for the efficient recovery of lithium in lithium iron phosphate batteries.In this paper,the effects of chloride ion provider,Fe³⁺and Li⁺molar ration and Cl^-concentration on the extraction of lithium ion from tributyl phosphate were studied by simulation experiments,the optimal extraction conditions for the obtained lithium ions were as follows:FeCl₃ and AlCl₃ were used as chloride ion provider,the Cl^-concentration was 5mol/L,and the molar ration of Fe³⁺to Li⁺was 1.5.Under these conditions,the extraction rates of different concentrations of Li⁺can research more than 85%.The stripping was carried out using hydrochloric acid,and the strpping rate was 90%at 6mol/L.According to the results of the simulation experiment and the characteristics of iron and lithium in the cathode material of the spent lithium iron phosphate battery,a leaching system composed of hydrochloric acid and hydrogen peroxide is used to obtain a solution containing a certain concentration of iron chloride and lithium chloride.The suitable conditions for the efficient separation and recovery of lithium from the cathode electrode by tributyl phosphate were established by supplementing the synergist and further optimizing the extraction conditions.After two-stage extraction at a ratio of organic to aqueous is 0.5,the lithium ion extraction rate was 92%.At the same time,after three-stage stripping of the organic phase with 6mol/L hydrochloric acid,the stripping rate was greater than 90%.The selective extraction of lithium ions by tributyl phosphate can effectively control the simultaneous transfer of the accompanying elements in the cathode electrode material,and the obtained high-purity lithium ion solution is advantageous for preparing for preparing lithium or lithium chemicals.In this paper,the Raman spectrum and the change of Cl^-concentration in the aqueous were obtained by Raman spectroscopy,ion chromatography and other techniques.By analyzing the Raman spectrum of the extracted organic phase,the change of Cl^-concentration,and the relationship between the characteristic peak area of the Raman spectrum and the Li⁺concentration in the aqueous solution,it was found that the simultaneous transfer of lithium ions and[FeCl₄]^-complex anionsduring the extraction of tributyl phosphate revealed that lithium was extracted and separated in the form of[LiFeCl₄]·nTBP.