氟化铁正极材料的制备及锂电性能研究  

Synthesis of iron trifluoride cathode materials and electrochemical performance of lithium ion batteries

作　　者：乔文灿 赵成龙 王瑛 杨剑[2] QIAO Wen-can;ZHAO Cheng-long;WANG Ying;YANG Jia(Shandong Yuhuang New Energy Techology Co., Ltd., Heze Shandong 274000, China;School of Chemistry and Chemical Engineering, Shandong University, Jinan Shandong 250100, China)

机构地区：[1]山东玉皇新能源科技有限公司,山东菏泽274000 [2]山东大学化学与化工学院,山东济南250100

出　　处：《电源技术》2019年第2期196-200,共5页Chinese Journal of Power Sources

基　　金：国家自然科学基金(51172076和21471090);国家"973"计划(2011CB935901)

摘　　要：采用三种不同的化学合成方法制备出形貌不同、结晶水含量不同的氟化铁[Fe F_3·(H_2O)_(0.33)和β-Fe F_3·3H_2O]材料,并对其结构、形貌进行表征,同时研究了氟化铁作为正极材料的锂电性能。实验结果表明,在三种材料中,介孔球状的Fe F_3·(H_2O)_(0.33)的电化学性能最为理想,β-Fe F_3·3H_2O方块的电化学性能其次,块状的Fe F_3·(H_2O)_(0.33)性能最差。其中,球状的Fe F_3·(H_2O)_(0.33)在142 mA/g电流密度下,循环充放电100圈后放电比容量仍然能够保持在159.1 mAh/g;方块状的β-Fe F_3·3H_2O在474 mA/g的大电流密度下,循环充放电50圈后放电比容量也可以维持在129.2 mAh/g。介孔材料大的比表面积,不仅增加了电解液和电极之间的接触面积,降低了锂离子的扩散路径,而且也能够缓冲循环过程中的体积变化,这些因素共同促进了其优异的电化学性能。Iron trifluoride with different morphologies and contents of crystalline water including FeF3·(H2O)0.33 andβ-FeF3·3H2O were prepared via different wet-chemistry methods. Their crystal structures and micromorphologies were characterized by XRD and SEM techniques. As cathode materials, mesoporous sphere-like FeF3·(H2O)0.33 and cubic-like β-FeF3·3H2O structures exhibit better electrochemical performance than bulk-like FeF3·(H2O)0.33 particles.The as-prepared mesoporous sphere-like FeF3·(H2O)0.33 exhibits a discharge specific capacity of 159.2 mAh/g at 142 mA/g after 100 cycles. Meanwhile, β-FeF3·3H2O with cubic structures also delivers excellent cycle stability, even at a high current density of 474 mAh/g, its discharge specific capacity is as high as 129.2 mAh/g after 50 cycles. The remarkable electrochemical performance could be attributed to the large specific surface area of mesoporous materials, which not only effectively increase the contact area between the active materials and the electrolyte and reduce the Li-ion diffusion pathway, but also buffer the volume changes during cycling.

关 键 词：氟化铁 正极材料 锂离子电池 

分 类 号：TM912[电气工程—电力电子与电力传动]