Dissertation > Excellent graduate degree dissertation topics show

Study on Synthesis and Performance of Li3V2（PO4）3 Cathode Materials for Lithium-ion Batteries

Author: YeZhiQiang
Tutor: JiangBaiQuan
School: Nanchang University
Course: Chemical processes
Keywords: Li3V2（PO4）3 microwave carbon-thermal reduction method rare earth microwave sol-gel method orthogonal experiments
CLC: TM912
Type: Master's thesis
Year: 2008
Downloads: 110
Quote: 0
Read: Download Dissertation

Abstract


Nasicon-structured Li3V2（PO4）3 is considerd as one of the most potential cathode materials for lithium-ion batteries, due to its advantages such as the friendly environment, low cost, stable structure , high safety and good electrochemical performance. The synthesis method, appearance, element doping, electrochemical behavior and kineties of lithiumin sertion-extraction process of Li3V2（PO4）3 as cathode materials were studied in detail in this dissertation. Research results are summed up as follows:1. The Li3V)2（PO4）3 sample of monoclinic crystal was synthssized by microwavecarbon-thermal reduction method, with the molar ratio of n（ Li）: n（V）: n（P） to 3.05: 2: 3 heated for 10 min by microwave. After charge-discharge cut-off voltages of 3.0-4.8V ,the sample derived a initial charge specific capacity of 160.83 mAh/g and a initial discharge specific capacity of 145.38mAh/g. And the sample retained a discharge specific capacity of 127.21 mAh/g after charge-discharged at 0.2 C rate for 30 cycles.2. La、Y、Ce oxides were doped to synthssize the samples by microwave carbon-thermal reduction method , for which the effect of La、Ce doping were fine.The sample of Li3.05V1.98La0.02（PO4）3 derived a initial charge specific capacity of 168.75 mAh/g and a a initial discharge specific capacity of 153.28mAh/g after charge-discharge cut-off voltages of 3.0-4.8V. and the cycle performance had been improved a certain extent.The sample of Li3.05V1.98Ce0.02（PO4）3 derived a initial charge specific capacity of 168.32 mAh/g and a a initial discharge specific capacity of 150.56 mAh/g after charge-discharge cut-off voltages of 3.0-4.8V.After charge-discharged at 0.2 C rate for 30 cycles,the sample retained a discharge specific capacity of 142.58 mAh/g ,the attenuation ratio of discharge specific capacity was 5.3%.3. Orthogonal experiments were used to investigate the effective factors in the synthesis process of the samples by microwave sol-gel method. The optimized Li3V2（PO4）3 samples had a monoclinic crystal ,which had integrative crytal lattice and were ordered.The sample derived a initial charge specific capacity of 172.42 mAh/g and a a initial discharge specific capacity of 154.38mAh/g after charge-discharge cut-off voltages of 3.0-4.8V.After charge-discharged at 0.2 C rate for 50 cycles,the sample retained a discharge specific capacity of 150.90 mAh/g, had almost no attenuation.4. Chemical diffusion coefficient of Li+ in these materials were studied for contrast,by the method of electrochemical impedance spectrum and theory deduction. Chemical diffusion coefficient of Li+ in the sample synthssized by microwave sol-gel method was the biggest and reached 1.434x10-8 cm2/s.5. The advantages and disadvantages of the three synthesis methods were comparedby disposed .parameters and electrochemical performance. The result showed that the microwave carbon-thermal reduction method with rare earth doped was the best.

Related Dissertations

  1. The Preparation and Thermoelectric Properties of Rare Earth Subsituted Ag Composite Ca3Co4O9-Based Oxides,TQ174.1
  2. Optimizition of Compositions and Processing Parameters and Wear Properties of Cemented Carbides YG11R Modified by Nanosized Rare Earth,TG135.5
  3. Biological Effect of Rare Earth Element and Genetic Transformation on Arnebia Euchroma(Royle) Johnst.Cell,S567.239
  4. Anti-corrosion Property of Flake Zinc Epoxy Coating Doped with Rare Earth in SRB,TQ630.1
  5. Study on Bio-drying of Paper Mill Sludge,X793
  6. Studies of Luminescence Characteristics of Eu3+-doped Rare Earth Borates REBaB9O16 （RE=rare Earth Ions and Y）,O627.3
  7. Synthesis , structure and properties of lanthanide complexes of pyridine carboxylic acids,O627.3
  8. Preparation and Characterization of Rare-earth Luminescent Material CaWO4: Eu3+,TB383.1
  9. Synthesis Rare-earth Iron-based Oxide Nanoparticles for Visible Light Degradation of Rhodamine B,X703
  10. Study on the Photoluminescence Properties of the Rare Earth Doped Oxide Phosphors Prepared by Hydrothermal Method,TQ422
  11. AAO template prepared fluorescent polymer structure of one-dimensional array,TB383.1
  12. Study on Laser Surface Modification of Two Kinds of Super-alloys,TG174.4
  13. The Effect of Rare Earth Additive on the Structure and Property of the Steel for 25crmoa Sucker Rods,TG142.13
  14. Preparation and Luminous Property of Tm and Dy Doped YSZ Coating,TG174.442
  15. The Research on Preparation Technology and Sintering Behavior of Rare Earth Aluminates (Dy3Al5O12、 NdAlO3、LaAl11O18),TB383.3
  16. Study of High-Efficient Supported Catalysts for Synthesizing Poly-(Propylene-carbonate) and Their Founctional Applications,TQ314
  17. Studies on the Influence of Rare Earth Ce on Microstructure and Properties of Huge Heat Input SAW Seam Metal,TG445
  18. Toughening Modification of Glass Fiber Reinforced Unsaturated Polyester and Fluorescence of Rare Earth/ Unsaturated Polyester Composite,TQ327.1
  19. Study on Amorphous Copper-Based Catalysts for Direct Synthesis of Dimethyl Ether by Hydrogenation of Carbon Dioxide,TQ223.24
  20. Based on the spectrum of rare earth doped materials under conversion and Its Application,TM914.4
  21. Research on Zinc Oxide Varistors Doped with Rare Earth Oxides,TM54

CLC: > Industrial Technology > Electrotechnical > Independent power supply technology (direct power) > Battery
© 2012 www.DissertationTopic.Net  Mobile