Experimental Research On Resource Recycling Technology Of Waste Power Battery

The problem of environmental pollution and energy depletion in society today has become a problem that people urgently need to solve.However,with the continuous development of new energy vehicles,power batteries represented by lithium batteries have been widely used.With the large-scale use of power batteries,the number of used power batteries has also increased year by year.If waste power batteries are effectively recycled,on the one hand,they can reduce pollution to the environment,and on the other hand,they can generate economic benefits.As the current stage of research on the recycling of power batteries is still in its infancy.Therefore,how to efficiently utilize and recycle used power batteries has become a concern of the world.This paper analyzes the leaching toxicity of positive and negative electrode materials of lithium battery under three specific conditions,and summarizes the potential environmental impact of placing spent lithium batteries in surface leaching,landfill filtrate,and acid rain.Risk,and then through the full analysis of the three power lithium batteries to determine the distribution of different metals in the positive and negative materials of different lithium batteries,to provide experimental basis for the recycling of valuable metals in the cathode material of power lithium batteries.Lithium iron phosphate batteries with a relatively large market share of power lithium batteries are used as research objects for resource regeneration.By reviewing relevant literature and considering experimental conditions,etc.,a set of practical resources for valuable metal used in lithium iron phosphate anode materials is summarized.Recycling technology solutions.And refer to the program process step by step to carry out experimental work.First,the old lithium iron phosphate battery was discharged.The battery positive electrode was disassembled by mechanical dismantling.The alkali solution was used to dissolve the aluminum foil on the positive electrode.The active material Li FeO₄ on the positive electrode was separated from the current collector aluminum foil to obtain the positive electrode material containing Li Fe O₄,and then H₂SO₄.The H₂O₂ acid system was used for acid leaching of the positive electrode material.The pH of the acid leaching solution wasadjusted by adding sodium hydroxide to recover the Fe³⁺in the leaching solution.The concentrations of Fe³⁺and Li+in the leaching solution at different pH values were determined.Calculate and analyze the pH range of Fe³⁺in the optimal precipitation separation acid leaching solution.The precipitate of Fe³⁺was separated by filtration,and the filtrate was heated and concentrated.The Li+in the filtrate was precipitated using Na₂CO₃,filtered and dried to obtain Li₂CO₃ crystal.Finally,the recovered lithium carbonate was subjected to X-ray diffraction?XRD?and scanning electron microscope?SEM?.The pretreatment experiment results show that the saturated lithium iron phosphate battery can be used to completely discharge the remaining electricity in the battery;dissolving the aluminum foil in the alkaline solution to separate the positive electrode material has a satisfactory separation effect.The alkali concentration of 1.5 mol/L was selected.The amount of alkali added to the liquid and the solid-liquid ratio of 1:30 is the best separation condition for the positive electrode active material and the aluminum foil.A single factor experiment was conducted on the leaching process of LiFe O₄ positive electrode material through H₂SO₄+H₂O₂ acid system to determine the influence degree of sulfuric acid concentration,liquid-solid ratio,reaction temperature and reaction time on the leaching of Fe3+and Li+and to calculate the target metal leaching.The optimum conditions for obtaining the acid leaching positive electrode material are as follows:using 2 mol/L sulfuric acid,adding the acid amount of the solid to liquid ratio of 1:15,the reaction temperature of 80°C.,and the reaction time of 90 min.In the best leaching conditions,the leaching rates of iron and lithium reached 98%and 95%,respectively.The results of precipitation and separation experiments show that the effect of alkaline leaching to adjust pH precipitation and separation of Fe³⁺is better,and the effect of alkaline leaching and impurity removal is obvious.Alkaline leaching Fe3+separation optimum conditions:pH=8;and under the conditions of the basic impurity element aluminum,zinc,copper removal,this time the precipitation rate of Fe³⁺can reach 97%or more;the optimal conditions for the concentration of crystalline lithium:Concentrated After the Li⁺concentration is not less than 15g/L,the lithium reaction time is not less than 60min,the amount of sodium carbonate is 110%of the Li⁺content,the reaction temperature is 90°C,the aging time is 15h,and repeated experiments are performed under the above conditions.The recovery rate of lithium is basically stable at around 90%.The results of the phase structure characterization of the recovered lithium carbonate samples show that the obtained recycled lithium carbonate has high crystallinity,complete cell structure,good crystal structure order,and the sample except a few large sized massive particles.The rest of the particles are in the form of granules,the size is relatively uniform,and the surface is smooth and complete.The comparison results of the reference lithium carbonate obtained by recovering lithium carbonate show that the lithium carbonate sample obtained by the lithium recovery method is of good purity.