摘要
采用溶剂热法,以乙二醇为溶剂,P123为软模板剂,制备了锂离子电池正极材料磷酸铁锂(LiFePO4),其振实密度约为1.2g·cm-3。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HRTEM)和BET对样品的成分、晶型,形貌和孔结构进行了表征。结果表明:鸟巢状LiFePO4由单晶纳米片组成,具有开放的三维多孔分级结构。通过时间单因素实验探讨鸟巢状分级结构LiFePO4的生长机理,其生长过程可以概括为:成核——定向生长——团聚——定向生长。电化学性能测试结果表明材料在0.1C倍率下充放电时,其首次放电比容量达132.5 mAh·g-1。
The cathode material LiFePO4 with tap density of ca. 1.2 g·cm-3 was synthesized by solvothermal method, using P123 as soft template and ethylene glycol as solvent. The composition, crystal shape, morphology and pore structure of the as-prepared samples were characterized by X-ray diffraction(XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET). The results show that the nest-like LiFePO4 consists of single-crystalline nanoplates with an open three-dimensional porous hierarchical structure. A reasonable formation mechanism is proposed based on time dependent experiments. The main evolving process involves the following steps: nucleation, oriented growth, aggregation and oriented growth. The electrochemical testing results show that the initial discharge specific capacities of nest-like LiFePO4 reach to 132.5 mAh·g-1 at 0.1C.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2014年第2期235-241,共7页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.21276286)资助项目