Study On Melting And Doping For Lithium Batteries

Since the new century, as the environmental pollution intensifies and the resource is exhausted seriously, people are stepping up exploring a green resource that can be recycled to meet the needs of modern society and emerging ecological problems. Energy storage equipment arises at the historic moment, lithium ion battery is the most widely used energy storage equipment among various kinds of energy conversion and storage devices. Vanadium pentoxide (V2O5), which is a material with low cost, no pollution and high theoretical capacity, is widely concerned by researchers.However, its structure will occurs irreversible change in process of charging and discharging, resulting in poor cycle stability of the system, and its electrical conductivity and lithium ion diffusion rate is relatively low, which hindering its further development and ultilization in industry production and Social life. In this paper, the cathode materials are synthesized by improving the preparation method and doping modification. The specific research works are as follows:The Mo-doped V3MoOX materials were synthesized by high-temperture melting.The XRD results showed that the structure of the material was not changed by doping but the crystallinity of the doped material increased. The SEM analysis showed that the material synthesized by high temperature melting method appeared in granular. The control experimental results showed that the material of A-V3MoOx synthesized by cooling the precursor in air had better electrochemical performance. Its first discharge capacity was 426mAhg-1 and its initial coulomb efficiency was 74.6%. Though the initial coulomb efficiency was not high, the capacity attenuation rate decreased with cycling.The Ni-doped cathode material was synthesized by high-temperture melting. The raw material NiO and V2O5 powder were mixed uniformly and calcined to obtain precursor V2oNiOx which was reduced in the furnace full of hydrogen to synthesize the desired material. The phase and morphology analyses of materials were respectively characterized by the detection of X-ray diffraction (XRD) and scanning electron microscopy(SEM). The electrochemical properties of materials were examined by galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The control experimental results showed when the optimal reduction temperature was at 250?, the material of C-V20NiOx had the optimal electrochemical properties. At the time,the first discharge capacity was 388mAhg-1 and the initial coulomb efficiency was 105%.In addition, the discharge capacity still reached 267mAhg-1 after 50 cycles, and capacity retention rate was 71.5%.