摘要
主要研究了纳米氧化铝包覆对LiFePO4/C复合正极材料结构和电化学特性的影响。采用溶胶凝胶方法把纳米氧化铝包覆在商业LiFePO4/C颗粒表面。研究了Al2O3包覆层的量对LiFePO4电极在室温和高温充放电性能的影响。结果显示:2wt%Al2O3包覆层能有效增加电池的循环容量,能延缓电池在高温条件下充放电的容量衰减,减小电极的界面阻抗。这归因于氧化铝包覆层对磷酸铁锂晶粒的表面起保护作用,减少电解液对磷酸铁锂晶粒表面的腐蚀,从而改善循环过程中磷酸铁锂的表面结构的完整和稳定,确保锂离子扩散通道的畅通。
The structure and electrochemical performance of Al2O3-coated LiFePO4 cathode materials were investigated. A nano Al2O3 coating on the surface of commercial LiFePO4/C particles (Aleees Inc.) was prepared by using the Sol-Gel method. The effect of the amount of Al2O3 coating on the electrochemical performance and structural stability of LiFePO4 electrodes at room temperature (25℃) and elevated temperatures (55℃) was studied. The results show that 2wt% Al2O3 coating can effectively enhance the cycling capacity, alleviate capacity fading at high temperature and reduce cell impedance. It is largely attributed to Al2O3 coating, which plays a regulatory role of lithium-ion inserting the lattice and preventing direct contact between the cathode material and the electrolyte, and improves the structural stability of LiFePO4 during cycles.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第11期1265-1269,共5页
Journal of Inorganic Materials
基金
Shenzhen Science and Technology Plan Foundation(08LH-03)