Dissertation > Excellent graduate degree dissertation topics show

Synthesis and Performance Research of Lithium-rich Manganes-based Li1.2Mn0.54Ni0.13O2

Author: ShengXia
Tutor: ChenMeng
School: Harbin Engineering University
Course: Applied Chemistry
Keywords: lithium ion battery lithium-rich cathode material gradient material droped
CLC: TM912
Type: Master's thesis
Year: 2013
Downloads: 68
Quote: 0
Read: Download Dissertation

Abstract


In recent years, lithium-rich manganes-based material has attract much attention ofparties scientists for its advantage of high capacity、high voltage、low cost,but the lowerfirst-time coulomb efficiency and poor rate performance with lower cycle performance of ithave greatly hinder its practical application. In this paper, we synthesized sphericalLi1.2Mn0.54Ni0.13Co0.13O2with carbonate co-precipitation method after the study of themanganese-based lithium-rich material. This article analysised and studyed the structure andmorphology, composition and electrochemical properties, and its concentration-gradientcoating modification and carbon nanotubes doping modificationits resolve performanceissues.The uniform spherical precursor particles Mn0.66Co0.17Ni0.17CO3was synthesized bycarbonate co-precipitation method, then the material was used to synthesize cathode materialLi1.2Mn0.54Ni0.13Co0.13O2through optimized high-temperature calcination process. By meansof SEM, XRD, TG were used to characterize the composition and structure of the material,the results show that the material has a layered structure and spherical morphology. Thecharge-discharge test results showed that the first discharge capacity Li1.2Mn0.54Ni0.13Co0.13O2of0.1C rate was283.9mAh/g and the first coulomb efficiency was76.3%, after50charge-discharge cycles the capacity retention rate of92.2%. The rate performance wasgenerally but the cycle performance under different rate is excellent.We synthesized concentration-gradient GC-LMO material to enhance the cyclingperformance of Li1.2Mn0.54Ni0.13Co0.13O2. The spherical material was constituted by a highspecific energy core of Li1.2Mn0.54Ni0.13Co0.13O2, a high cycle performance Li1.13Mn0.47-Ni0.2Co0.2O2shell layer and an intermediate concentration-gradient transition layer for thepurpose of maintainingenhance the cycle performance of the material on the basis of thehigher capacity. The EDX test proved the prepared material having the design of aconcentration gradient through the cross-section, while the material at the0.1C rate50timesthe cycle capacity retention rate was98%, the capacity retention rate was91.4%after500cycles at1C, raterepresenting an72.1%capacity retention rate of Li1.2Mn0.54Ni0.13Co0.13O2has been greatly improved.We also synthesized carbon nanotubes doped precursor to prepare of CNT&x=0.5LMO with3D pore structure for the purpose of upgrading the first coulombic efficiency and ratecapability of Li1.2Mn0.54Ni0.13Co0.13O2. The charge-discharge test results showed that the firstdischarge capacity CNT&x=0.5LMO of0.1C rate was303.2mAh/g and the first coulombefficiency was90.4%, the first coulomb efficiency has been greatly improved. The1C rateinitial discharge capacity of CNT&x=0.5LMO is218.7mAh/g, compared to1C rate initialdischarge capacity of Li1.2Mn0.54Ni0.13Co0.13O2（190.6mAh/g） increased14.7%. Electro-chemical tests prove that f-CNTs doped precursor preparation with3D pore structure of thecathode material can improve the the first Coulomb efficiency and magnificationperformance.

Related Dissertations

  1. Preparation and Properties of Silicon Carbon Anode for Lithium Ion Battery,TM912.9
  2. First-Principles Studies of Cathode Material Srn+1TinO3n+1（n=1,2,3,∞） for Solid Oxide Fuel Cell,TM911.4
  3. The Study of Li-rich Layered Solid-Solution Cathode Materials for Lithium Ion Batteries,TM912
  4. Preparation of Silicon-based Alloy Anode Material Andelectrochemical Properties,TM912
  5. Research of Graphitized Needle Coke Coated by Phenolic Resin Pyrolytic Carbon as Anode Material for Lithium Ion Battery,TM912
  6. Preparation and Modification of Lithium Ion Battery LiNi0.8Co0.05O2 Cathode,TM912
  7. Effect of Water Binder on the Electrochemical Performance of Graphite,TM912
  8. Preparation and Performance Research of Lithium Ion Battery Anode Material Li4Ti5O12,TM912
  9. Synthesis and Properties of Spinel Limn2 O4 as Cathode Material,TM912
  10. Study lithium titanate prepared from ilmenite,TM912
  11. Synthesis and Modification of Cathode Materials LiFePO4 and Li2FeSiO4 for Lithium Ion Battery,TM912
  12. Lithium-Ion Battery Equalization System Simulation Study on Bidirectional Flyback DC-DC Converter,U463.633
  13. Preparation of the High Voltage LiNi0.5 Mn1.5 O4 Cathode Material and in Situ Xrd Study for Its Phase Transition,TM912
  14. Supercritical Method Preparation for Lithium Iron Phosphate Nanometer Material and Its Carbon-coating Research,TM912
  15. Research on Functional Electrolytes for Lithium Ion Battery,TM912
  16. Synthesis and Modification of Nano LiFePO4 as Cathode Materials,TM912
  17. Study on Synthesis and Modified of LiFePO4 as Cathode Materials,TM912
  18. Preparation and Research Electrochemical Properties of LiFePO4 for Cathode Material of Lithium-ion Batteries,TM912
  19. New Rechargeable Magnesium Battery Cathode Material silicate Cobalt Magnesium Preparation and Properties,TM912
  20. Graphite anode low temperature performance influencing factors and improving research,TM912
  21. New lithium -ion battery anode material Li 4 Ti 5 O 12 Preparation and Modification,TM912

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