| With the continuous development of Chinese economy,the demand for electrolytic manganese products is increasing,and the consumption of manganese ore is also increasing.However,Chinese manganese ore resources are unevenly distributed,there are few high-grade manganese deposits,small manganese ore deposits,many poor ores.The impurity content is high,and the ore structure in the manganese ore deposit is more complicated,which will bring great difficulty to the processing and utilization of manganese ore.Therefore,manganese-rich and high-quality manganese ore resources are very scarce mineral resources in China.The electrolytic manganese anode slime is a by-product produced in the anode area during the production of metal manganese by electrolysis,in which the Mn content is 40%-50%.The chemical composition and physical structure of electrolytic manganese anode slime are complex and changeable.At present,there is no proper disposal method in the industry.Most of them are treated as solid waste,which not only causes waste of manganese resources,but also causes great pollution to the environment.Therefore,the research on the utilization technology of electrolytic anode slime is urgent.This article takes electrolytic manganese anode slime as the research object,prepares it into active manganese dioxide through roasting-purification-disproportionation process,and uses it as a manganese source to prepare lithium-rich manganese-based cathode materials to achieve the purpose of resource utilization through single factor in the experiment and orthogonal experiment,the effects of temperature,time,sulfuric acid concentration,liquid-solid ratio and other factors on the reaction conversion rate during sulfuric acid disproportionation were analyzed,the optimal disproportionation process was explored,and the prepared active manganese dioxide was characterized and analyse.In this paper,600?800?high temperature calcined electrolytic manganese anode slime was used.The anode slime was leached with 2 mol/L ammonium acetate at 80?for 30 min to remove impurities in the electrolytic manganese anode slime,and then modified by sulfuric acid disproportionation.The effects of temperature,time,sulfuric acid concentration,liquid-solid ratio and other factors on the reaction conversion rate were discussed.The results show that the reaction conversion rate can reach 95.86%under the conditions of temperature 70?,time 100 min,liquid-solid ratio 8:1,and sulfuric acid mass concentration 20%.The product particles are uniform and the particle size is small,which is a mixed Mn O2 composed of?-Mn O2 and?-Mn O2.In addition,the effects of the precipitant(Na OH)concentration and co-precipitation temperature on the morphology and electrochemical performance of the cathode material during the co-precipitation process of preparing the cathode material precursor were also investigated,and the effects of different manganese sources on the cathode material prepared were analyzed.influences.The lithium-rich manganese-based cathode material 0.5Li2Mn O3·0.5Li[Ni0.4Co0.1Mn0.5]O2 was prepared by coprecipitation-high temperature roasting method.The concentration of the precipitant(Na OH)and coprecipitation temperature during the coprecipitation process were investigated.The influence of morphological structure and electrochemical performance,through characterization and electrochemical performance test of the prepared cathode material,it was determined that the best precipitant(Na OH)concentration was 1mol/L,and the co-precipitation temperature was 60?.The results show that the first charge-discharge specific capacity of the cathode material prepared under the best conditions is 380.4 mAh/g and 236.8 mAh/g.After 50 charge-discharge cycles,the discharge specific capacity is 173.6 mAh/g and the capacity retention rate is73.31%.In this paper,0.5Li2Mn O3·0.5Li[Ni0.4Co0.1Mn0.5]O2 lithium-rich manganese-based positive electrode materials prepared by different manganese sources were tested and analyzed.Preliminary analysis of the effect of different Mn O2 on the prepared cathode material,XRD analysis of each manganese source,found that the commercially available chemical manganese dioxide(CMD)and electrolytic manganese dioxide(EMD)are common Mn O2 of JCPDS card number 04-0799,The electrolytic manganese dioxide(AEMD)processed by sulfuric acid disproportionation process and the active manganese dioxide(AMD)prepared by electrolytic manganese anode slime are both mixed Mn O2 composed of?-Mn O2 and?-Mn O2.The cathode material prepared by AEMD has a specific charge capacity of 391.6 mAh/g for the first time and a discharge specific capacity of 242.8 mAh/g,which is slightly higher than that prepared by AMD and much larger than that prepared by ordinary manganese dioxide.Therefore,active manganese dioxide(AMD)prepared from electrolytic manganese anode slime can be used as a manganese source for the synthesis of lithium-rich manganese-based cathode materials. |
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