原位聚合物限制法合成核-壳结构的LiFePO4/C纳米复合材料及其热分析动力学研究(英文)

Synthesis of a LiFePO_4/C Nano-Material with a Core-shell Structure by an in-situ Polymerization Restriction Method and its Thermal Decomposition Kinetics

以FeCl_36H_2O、NH_4H_2PO_4、CH_3COOLi等为原料,通过原位聚合物限制法制备出了具有核-壳结构的LiFePO4/C纳水材料,利用XRD、HRTEM和TG-DSC等分析测试手段对材料的组成、形貌和热稳定进行表征。结果表明,LiFePO_4/C纳米材料是由20~40 nm的LiFePO4核和1~2 nm的炭壳组成。LiFePO_4/C纳米材料的热分解机理为1维随机成核,热分解动力学公式为da/dT=(A/β)exp(-E_a/RT)(1-a),动力学参数为lgA=10.386 min^(-1),E_a=1 38.849 kJ·mol^(-1)

LiFePCVC nano material with a core-shell structure was synthesized by an in-situ polymerization restriction method using FeCl_3·6H_2O,NH_4H_2PO_4,aniline(C_6H_5NH_2) and CH_3COOLi as raw materials.The composition and microstructure of LiFePCVC nano material were characterized by XRD and HRTEM.The thermal decomposition kinetics of the sample was studied through non-isothermal TG-DTG method.The results show that the LiFePCVC nano-material with a core-shell structure is formed from a highly crystalline LiFePO_4 core with a size of about 20~40 nm and a carbon shell with a thickness of about 1-2 nm.The possible thermal decomposition mechanism of the samples is 1-D random nucleation,and its thermal decomposition kinetic equation is da/dT=(A/β)exp(-E_a/RT)(1-a).The kinetic parameters are:lgA= 10.386 min^(-1)and E_a =138.849 kJ·mol^(-1).