磷酸铁包覆纳米锰酸锂的改性研究  

The Effect of FePO_4 Coating on Electrochemical Performance for Nano-LiMn_2O_4 Cathode Material

作　　者：李爽[1] 张五星[1] 杨泽[2] 梅鑫涛[1] 吕文中[1] 胡先罗[2] 袁利霞[2] 黄云辉[2] 

机构地区：[1]华中科技大学电子科学与技术系,武汉430074 [2]华中科技大学材料科学与工程学院,武汉430074

出　　处：《材料导报》2011年第6期53-57,共5页Materials Reports

基　　金：国家杰出青年科学基金(50825203);国家技术研究发展计划863项目(2009AA03Z225);湖北省自然科学基金重点项目(2008CDA026);武汉市青年科技晨光计划资助项目(200850731354)

摘　　要：以水热法合成的纳米MnO2为模板,合成了以棒状结构为组成单元的球状LiMn2O4纳米材料,并首次用FePO4对其进行了表面包覆改性。通过XRD、SEM、TEM、EDS等表征手段对材料的结构、形貌及组成元素进行了分析,并测试了材料的电化学性能。结果表明,经过1%(质量分数)FePO4包覆的LiMn2O4材料的电化学性能得到明显改善,在1C下首次放电比容量达128.6mAh/g,循环100次后仍保持97.3mAh/g,容量保持率为75.7%;在0.1C下充电,在0.1C、0.2C、0.5C、1C、2C、3C、4C下连续放电,放电比容量分别可达131.2mAh/g、128.0mAh/g、127.1mAh/g、126.0mAh/g、117.8mAh/g、110.9mAh/g和104.6mAh/g。Uniform LiMn2O, spheres, consisting of nanorods, was prepared by nano-MnO2 template and modified by FePO4 coating. The obtained materials were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, and energy dispersive spectrometry（EDS）. Meanwhile, their electrochemical properties were characterized by electrochemical method. The results demonstrate that the LiMn2O4 coated with 1wt% FePO4 shows an initial discharge capacity of 128. 6mAh/g at 1C, and still remains of 97.3 mAh/g after 100 cycles. When discharged at 0. 1C, 0. 2C, 0. 5C, 1C, 2C, 3C and 4C, its discharge capacity could reach 131.2mAh/g, 128. 0mAh/g, 127. lmAh/g, 126.0mAh/g, 117. 8mAh/g, 110. 9mAh/g and 104. 6mAh/g, respectively. It indicates that, compared with the parent, the electrochemical perfomance is significantly improved after modification.

关 键 词：锰酸锂 表面包覆 磷酸铁 锂离子电池 

分 类 号：O646[理学—物理化学]