Synthesis And Properties Of Carbon Electrode Materials Derived From Biomass For Zinc-Air Batteries

Zinc-air batteries have drawn a widely researchers attention due to its advantages such as high energy density,safety,stability,and non-pollution.In recent years,zinc-air batteries have become one of the hotpots especially in the field of power batteries used in new enery vehicles.As one of the core parts of zinc-air batteries,air electrode catalyst materials directly determines the performance of zinc-air batteries.At present,the electrode catalyst materials used in zincair batteries are mainly noble metal materials with high electrochemical activity.However,the disadvantages of noble metal materials,such as small reserves,high cost and poor stability,seriously hamper the commercialized development of zinc-air batteries.For these,this dissertation focuses on renewable,low-cost carbon electrode materials derived from biomass.In order to solve the problem of poor electrocatalytic activity,a series of low cost,high electrocatalytic activity and good stability heteroatom-doped biomass carbon electrode catalyst materials were designed and synthesized.The effects of heteroatom doping and different heat treatment temperatures on the oxygen reduction reaction performance of biomass carbon electrode catalyst materials were investigated.The actual catalytic performance of the synthesized electrode catalyst materials in this dissertation was deeply discussed.The electrochemical performance of zinc-air batteries was studied by using the prepared electrode catalyst materials as the air electrode catalyst materials for zinc-air batteries.The main content of this dissertation is as follows:(1)The nitrogen and sulfur dual-doped biomass carbon materials derived from platanus villous were synthesized by high-temperature heat treatment.By systematically studying the microscopic morphology,composition and oxygen reduction performance of the synthetic biomass carbon materials,the different influence of heteroatom doping on the electrode catalyst materials were investigated.The electrochemical performance of the zinc-air batteries used the best synthesized electrode catalyst materials for air electrode was studied.The result showed that the best synthesized electrode catalyst materials had good discharge stability.(2)Another nitrogen and sulfur dual-doped biomass carbon electrode materials were prepared by sophora flowers with more porous.By adjusting the heat treatment temperature,the effect of heat treatment temperature on the morphology and electrochemical performance of the electrode catalyst materials were investigated.The biomass carbon electrode materials derived from sophora flowers exhibited high oxygen reduction reaction activity.The performance of zinc-air battery with electrode catalyst materials derived from sophora flowers demonstrated excellent electrochemical properties and good discharge stability.(3)Taking into account the advantages of self-doping carbon electrode materials,such as low cost and high heteroatom content,nitrogen-,sulfur-,phosphorus-codoped biomass carbon materials derived from dictyophora indusiata were designed and prepared.A series of physical characterization methods were used to analyze the micro-morphology,composition and doping element content of synthetic electrode catalyst materials.The influence of the content of the doping elements on the electrocatalytic activity of the electrode catalyst materials was emphatically explored.The best electrocatalytic performance of electrode catalyst materials exceeded that of commercial Pt/C in terms of onset potential,half-wave potential,specific capacity of zinc-air batteries,and discharge stability.The outstanding electrode catalyst materials can be used as alternative commercial Pt/C for zinc-air batteries and new energy vehicle in the future.