| Biological template method is a important synthesis method that the use of yeast,bamboo carbon and other biological tissue as a template by biological self-assemblyadjust LiFePO4synthesis process.Yeast biological templates in the synthesis processnot only can be used as a biological templates, but carbon source by formation ofconductive carbon and reductant at heat treatment.High performance LiFePO4/mesoporous biological carbon-Li2O-P2O5compositematerial is synthesised through method of biological templates-sol gel that yeast as atemplate.Mesoporous three-dimensional network of biological carbon-Li2O-P2O5glasscoating layer not only can improve the electronic conductivity of LiFePO4by thebiological carbon, but improves the lithium ion conductivity of LiFePO4through theLi2O-P2O5glassy state. In the process of charging and discharging, electrical activitycladding layer of the positive series LiFePO4, compensate for the loss of specificstorage layer to improve the energy density of electrode materials. Electrochemicalperformance test result show that the synthesis of LiFePO4cathode material in0.1Cratio given182.3mAh g-1, the coulomb efficiency of close to100%, after107times.It was discussed that Lithium ion interface transmission mechanism that theinfluence of interface between LiFePO4crystal particles cladding layer and theelectrolyte on the electrode material electrochemical performance; Specific capacityattenuation mechanism of the battery after many cycles is studied after the specificcapacity attenuation. The mesoporous network biological carbon-Li2O-P2O5glassy stateon the surface of LiFePO4between cladding layer and the electrolyte formed the electricdouble layer interface due to the effect of surface charge improves the lithium ionsediment concentration on the electrolyte interface in LiFePO4and strengthen theinvasion of electrolyte to the anode material. The transmission in three directions ofLithium ions in the glassy state transfer layer on the surface of the LiFePO4,along thethree-dimensional lithium ion channel, improve the efficiency of the lithium ionmigration. Battery charge and discharge several times cycle after the batterycomponents in addition to the positive electrode were obvious changes. The mainreason of specific capacity attenuation is that attenuation damage of battery components. The doped copper ions LiFePO4/carbon composite material is synthesised throughbiological templates-coprecipitation and yeast as the template. Yeast as biologicaltemplates in LiFePO4is formed on the surface of the three-dimensional networkstructure of carbon coated layer, reduce impedance of the charge and discharge processon the interface between the electrode materials and electrolyte, improving theelectronic conductivity of LiFePO4. Yeast template biological self-assembly adjustcopper ion doping process of LiFePO4that high ionic conductivity of copper andformed a new phase in the LiFePO4crystal structure increase the the transmission pathof lithium ions in the LiFePO4crystal structure and improve the LiFePO4electronic andlithium ion conductivity. Electrochemical performance test results show that the dopedcopper ion of LiFePO4cathode material in0.1C ratio have the specific capacity of165.3mAh g-1, close to the theoretical specific capacity and small discharge polarization,coulomb efficiency is close to100%.The bamboo carbon-LiFePO4-C composite materials is created by biologicaltemplates-solvothermal method and Biological bamboo carbon as the template. Becauseadsorption of biological bamboo carbon templates that deposit large amounts of iron ionand lithium ion, LiFePO4crystal particles generated in the bamboo carbon surface afterheat treatment.Biological bamboo carbon with high conductivity increase the electronicconductivity of LiFePO4.electrochemical performance test results show that the bamboocarbon-LiFePO4-C composites under0.1C ratio, release specific capacity131mAh g-1after100times charging and discharging cycle,the specific capacity attenuation rate isonly5.3%. |
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