tailieunhanh - Báo cáo hóa học: " LiMn2O4–yBry Nanoparticles Synthesized by a Room Temperature Solid-State Coordination Method"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: LiMn2O4–yBry Nanoparticles Synthesized by a Room Temperature Solid-State Coordination Method | Nanoscale Res Lett 2009 4 353-358 DOI S11671-009-9252-7 NANO EXPRESS LiMn2O4_yBry Nanoparticles Synthesized by a Room Temperature Solid-State Coordination Method Yudai Huang Rongrong Jiang Shu-Juan Bao Yali Cao Dianzeng Jia Received 22 July 2008 Accepted 8 January 2009 Published online 22 January 2009 to the authors 2009 Abstract LiMn2O4-yBry nanoparticles were synthesized successfully for the first time by a room temperature solidstate coordination method. X-ray diffractometry patterns indicated that the LiMn2O4-yBry powders were well-crystallized pure spinel phase. Transmission electron microscopy images showed that the LiMn2O4-yBry powders consisted of small and uniform nanosized particles. Synthesis conditions such as the calcination temperature and the content of Br- were investigated to optimize the ideal condition for preparing LiMn2O4-yBry with the best electrochemical performances. The optimized synthesis condition was found in this work the calcination temperature is 800 C and the content of Br- is . The initial discharge capacity of obtained from the optimized synthesis condition was 134 mAh g which is far higher than that of pure LiMn2O4 indicating introduction of Br- in LiMn2O4 is quite effective in improving the initial discharge capacity. Keywords LiMn2O4-yBry Nanoparticles Room temperature solid-state coordination method Lithium-ion battery Y. Huang R. Jiang . Bao Y. Cao D. Jia El Institute of Applied Chemistry Xinjiang University Urumqi 830046 People s Republic of China e-mail jdz@ Y. Huang Y. Cao D. Jia School of Science Xi an Jiaotong University Xi an 710049 People s Republic of China Introduction Development of the cathode materials for lithium-ion battery is vital to meet the demands of portable devices power tools e-bikes future usages of electric vehicles and so on 1 . Among three promising candidates for cathode materials LiCoO2 LiNiO2 and LiMn2O4 lithium manganese oxides LiMn2O4 2 are inexpensive .