非晶硼磷玻璃包覆Li[Li_(0.2)Co_(0.13)Ni_(0.13)Mn_(0.54)]O_2正极材料的研究  

Enhanced electrochemical property of amorphous borophosphate glasscoated Li[Li_(0.2)Co_(0.13)Ni_(0.13)Mn_(0.54)]O_2 cathode for lithium ion batteries

作　　者：尚珂会 何巍[1] 艾新平[1] 曹余良[1] 杨汉西[1] 

机构地区：[1]武汉大学化学与分子科学学院,湖北武汉430072

出　　处：《电源技术》2016年第2期247-251,共5页Chinese Journal of Power Sources

基　　金：国家"973"计划项目(2015CB25110)

摘　　要：采用聚合物热解的方法合成了富锂正极材料Li[Li0.2Co0.13Ni0.13Mn0.54]O2（RLMO）,并对其进行硼磷玻璃（BPG）表面包覆。经过X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）实验表明,材料颗粒尺寸在100~200 nm范围,其表面明显具有非晶包覆层,且表面包覆不会改变材料的主体结构。在2.0~4.8 V范围内进行恒流充放电测试表明,非晶硼磷玻璃包覆材料（BPG-RLMO）具有更高的首次放电比容量（279.5 m Ah/g,30 m A/g）、高的首次库仑效率（91.3%）和优异的循环稳定性（100次循环后容量保持率为86.4%,30 m A/g）。这些结果表明非晶硼磷玻璃包覆可有效抑制电解液的表面分解和所引起的表面结构破坏,提高了材料的首次库仑效率和循环稳定性,为高性能富锂正极材料的发展提供一种可借鉴途径。Layered Li[Li0.2Co0.13Ni0.13Mn0.54]O2nanoparticles were synthesized by a simple polymer-pyrolysis method and then coated with a borophosphate glass. The as-prepared borophosphate glass-coated Li-rich materials（BPG-RLMO） were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and transmission electron microscope（TEM）. The results demonstrate that the BPG-RLMO has a typical layered structure and a uniformly distributed nanosize of 100~200 nm. The electrochemical tests show that the coated sample has a high initial discharge capacity of 279.5 m Ah/g and initial coulombic efficiency of 91.3% at 30 m A/g. Additionally, the BPG-RLMO sample also exhibited excellent cycling performance with 86.4% capacity retention over 100 cycles at100 m A/g. The experimental results demonstrate that the decomposition of the electrolyte can be efficiently decreased by the borophosphate glass coating, and the destruction of the surface structure of the material is suppressed, so as to be favorable to improve the initial coulombic efficiency and cycling stability. It was a good choice to develop high-performance rich-Li manganese-base oxide materials.

关 键 词：锂离子电池 正极材料 富锂层状氧化物 硼磷玻璃 包覆 

分 类 号：TM912[电气工程—电力电子与电力传动]