Electrochemical performance of Li2MSiO4 (M=transition metal) Synthesized by Microwave Assisted Sol-Gel Process with Surface Modification

Title
Electrochemical performance of Li2MSiO4 (M=transition metal) Synthesized by Microwave Assisted Sol-Gel Process with Surface Modification
Authors
최전진임원빈장원영조병원김종학정경윤
Keywords
lithium orthosilicate; cathode
Issue Date
2012-04
Publisher
10th Spring Meeting of the International Society of Electrochemistry
Citation
, 119-119
Abstract
Lithium orthosilicate, Li2MSiO4 (M=Fe, Mn, Co and Ni), have recently attracted the attention of researchers due to high theoretical capacities (>300 mAhg-1) via extraction of more than one Li+ ion per formula unit and high thermal stability through strong Si- O bonding. Although the theoretical capacity is quite high, practical capacities achievable at reasonable cut-off voltages are not as much as expected. Major reasons for the poor performance of the lithium orthosilicate are poor electronic conductivity (<10-14 S cm-1 at RT) and ionic diffusivity causing a huge polarization during chargedischarge. When LiFePO4 was introduced as a cathode material for lithium ion batteries, it experienced the similar situation that its electrochemical performance is very poor due to low electronic conductivity. The low electronic conductivity problem of LiFePO4 was later alleviated by doping with metal ions and coating with carbon. In the present contribution we partly adopted a strategy of carbon coating which was effective on LiFePO4 to improve the electrochemical performance of Li2MSiO4 (M=transition metal). In addition to the carbon coating we tried to control the particle size distribution using microwave assisted sol-gel process. A detailed study on the influence of surface modification and synthesis routes of microwave assisted sol-gel process on the electrochemical performance of Li2MnSiO4 will be presented. The main focus of this contribution will be the improvement of the electrochemical performance of Li2MSiO4 by combining the high discharge capacity of Li2MnSiO4 with the good cycling stability of Li2FeSiO4. Li2(Mn1-xFex)SiO4 cathode materials have been synthesized via microwave assisted sol-gel method and high energy ball milling. Its structural variations during charging and discharging as well as its electrochemical performances will be discussed in detail at the meeting.
URI
http://pubs.kist.re.kr/handle/201004/42795
Appears in Collections:
KIST Publication > Conference Paper
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE