Study On The Preparation And Electrochemical Performance Of Amorphous Carbon Based On The Carbonized Polypyrrole

The focus of this century is resource utilization, economic development and environmentalprotection, and the development of battery technology is closely related to the aboved threeaspects. Since1991, lithium-ion batteries (LIBs) have set up in the secondary battery marketbecause of high voltage, high capacity, the advantages of the green environmental protection andlong cycle life. The key factors of determining LIBs performance are cathode material, anodematerial and electrolyte. The graphite as the commercial anode material possesses the low theorycapacity, so the development of the anode material is of great significance. Hard carbon with ahigh specific capacity and a lower price has gradually become one of the potential anodematerials in scientific research.The multi-walled carbon nanotubes (MWCNTs) with excellent mechanical properties andelectrical conductivity will add to the electrode materials, and can form the effective conductivenetwork, thus improve the charge/discharge performance and energy density of LIBs. TheMWCNTs and carbon form composite material. On the one hand, the MWCNTs with goodelectrical conductivity are advantageous to the electronic transfer in the composite. On the otherhand, the self bundle of the MWCNTs makes the electrolyte possess wettability to the composite,and is advantageous to the electrolyte ions transportation. In this paper, the main researchcontents and results are as follows:(1) The tubular polypyrrole and granular polypyrrole were fabricated. The polypyrrole wascarbonized at800℃,850℃,900℃and950℃,respectively. Then the amorphous carbonwas prepared. The samples were characterized through XRD, SEM and TEM, and theelectrochemical performance was tested. It is concluded that the optimal carbonizationtemperature is900℃.(2) The MWCNTs were used to modify the amorphous carbon. The amorphous carbon wasmixed with the MWCNTs (2.5wt%,5wt%and10wt%) under the ultrasonic electromagneticstirring. The effect of the MWCNTs content on the properties of the amorphouscarbon/MWCNTs composite was studied. It is found that the5wt%with the adding proportionis better than the others on the electrochemical properties.(3) The MWCNTs were used to modify the amorphous carbon, The amorphous carbon wasmixed with the MWCNTs (2.5wt%,5wt%and10wt%) under the ball-milling. The effect of the MWCNTs content on the properties of amorphous carbon/MWCNTs composite was studied.