Recovery And Preparation Of Cobalt Oxide Based On Recycling Of Used Lithium Ion Batteries And Its Photoelectric Properties

Nowadays,with the accelerated development of updating of electronic information products,the demand of lithium-ion battery increases,resulting in a large number of spent lithium ion battery.IF the battery discarded,the valuable metallic elements which contained in the spent lithium ion battery will be wasted largely.At the same time,the soil,the river,the air will be polluted by the poisonous elements,threatening human health.Along with a booming economy,energy sources like coal,oil and natural gas are increasingly reduced,making a severe impact in everyday life.In addition to this,poisonous air and pollutant discharge increasing causes a series of environment problems,such as global warming,sea level rising,fog and haze and acid rain.Therefore,people urgently need some clean renewable energy replacing traditional energy sources to significantly reduce the environmental pollution.However,green renewable energys can not be utilized for restrictions of territory,time,season,and it has been an urgent issue.To solve the problem,we need develop an energy-efficient storage system.Super capacitor is a device which can storage and convert energy and has good prospect,and has attracted much attention because of environmental protection,high safty performance,long service life,free maintenance,high capacity.It is of great significance to develop a high performance capacitor electrode material suitable for the market on account of the practical application of supercapacitor being restricted by the electrode material.In this paper,Co₃O₄ high performance active materials with a diversity of morphologies were successfully prepared by hydrothermal method,and characterized and tested their morphology,structure and electrochemical performance.And the project is of great significance and value to research for the development of supercapacitors.The main research work is as follows:（1）With HCl leaching solution as cobalt source,Co₃O₄ films are grown on FTO glass by the hydrothermal-decomposition method.The results of XRD and SEM showed that the samples have integrity crystal structure and high purity,and render nanorod array structure.The Co₃O₄ nanorod is composed of a large number of Co₃O₄ nanoparticles,and its diameter is about 80 nm,and the length is about 14μm.The electrochemical test results show that the capacity of Co₃O₄ electrode is 400 F/g and electrochemical properties are similar to those of the electrode materials made from pure drugs.（2）With HNO₃ leaching solution as cobalt source,Co₃O₄ films are grown on FTO glass by the hydrothermal-decomposition method.The results of XRD and SEM showed that the samples having integrity crystal structure and high purity,and render nanorod array structure.The Co₃O₄ nanorod is composed of a large number of Co₃O₄ nanoparticles,and its diameter is about 200 nm,and the length is about 14μm.The electrochemical test results show that the capacity of Co₃O₄ electrode is 502 F/g and electrochemical properties are similar to those of the electrode materials made from pure drugs.What’s more,the capacity of Co₃O₄ electrode produced by the HNO₃ leaching solution as cobalt source is better than by the HCl leaching solution.（3）Under the 160℃,the diameter of hollow Co₃O₄ nanoparticles is 1μm,which are prepared by one-step solvothermal method,using the HNO₃ leaching solution as cobalt source.The results of XRD and SEM showed that the samples having good dispersion and large surface area.The electrochemical test results show that the electrochemical properties are similar to those of the electrode materials made from pure drugs.The photocatalytic results showed that although the hollow Co₃O₄ nanoparticle had mesoporous structure,the photocatalytic effect was not ideal for rhodamine B.And the degradation process was mainly due to the adsorption of Co₃O₄ powder and the maximum adsorption capacity was 0.04548mg/g.