Al掺杂Li_2MnSiO_4锂离子电池正极材料的合成和电化学性能

以Li2SiO3、Mn(CH3COO)2.4H2O和Al(OH)3为原料,用传统高温固相合成法成功制备出Li2Al0.1Mn0.9SiO4锂离子电池正极材料。采用XRD、FESEM分析了正极材料的相组成、结构和形貌,利用电池测试仪测试了正极材料的电化学性能。研究结果表明,固相合成的产物主相为Li2Al0.1Mn0.9SiO4,同时存在少量的杂质,产物表面形貌为非球形颗粒,颗粒尺寸为100～500 nm。实验结果表明,Al掺杂后,正极材料的可逆容量和循环寿命都得到提高。正极材料电化学性能提高的机理在于Al掺杂稳定了Li2MnSiO4正极材料的结构。

Preparation and Electrochemical Performance of Al-doped Li_2MnSiO_4 Cathode Material for Lithium Ion Batteries

Li_2Al_(0.1)Mn_(0.9)Si0_4 cathode material for lithium ion batteries Was synthesized by traditional solid-state reaction method taking Li_2SiO_3，Mn(CH_3COO)_2·4H_2O and Al(OH)_3 as raw materials．XRD and FESEM were used to study the phase,structure and morphology of obtained samples.Electrochemical performance of the cathode material was tested.The results show that the main phase of sample prepared via solid-state reaction is Li_2Al_(0.1)Mn_(0.9)SiO_4,whereas a small amount of impurities exist.The particle size of Li_2Al_(0.1)Mn_(0.9)SiO_4 sample is 100-500 rm and the morphology of the particle shape is not sphere.The experiment results show that the reversible capacity and cycle life of cathode sample improve through doping Al,and its mechanism is that doping Al can stabilize the microstructure of Li_2MnSiO_4 cathode material.