CAJ | 학술논문

利用固相法合成了镧离子掺杂的Li1-xLaxFePO4正极材料,采用XRD,SEM和充放电性能表征了材料的晶体结构、微观形貌和电化学性能.研究表明,少量La3+的掺杂未影响到LiFePO4的晶体结构,但显著改变了粉体的微观形貌,降低颗粒粒度至纳米级,改善了可逆容量和循环性能.得到的最佳配比正极材料Li0.99La0.01FePO4,在C/20的充放电速率下,其初始可逆放电容量达到理论容量的73%-123 mAh/g,20次充放电循环后表现出良好的容量可循环性,容量没有衰减.引入稀土离子是提高磷酸铁锂新型锂离子正极材料电化学性能的有效方法.
이용고상법합성료란리자참잡적Li1-xLaxFePO4정겁재료,채용XRD,SEM화충방전성능표정료재료적정체결구、미관형모화전화학성능.연구표명,소량La3+적참잡미영향도LiFePO4적정체결구,단현저개변료분체적미관형모,강저과립립도지납미급,개선료가역용량화순배성능.득도적최가배비정겁재료Li0.99La0.01FePO4,재C/20적충방전속솔하,기초시가역방전용량체도이론용량적73%-123 mAh/g,20차충방전순배후표현출량호적용량가순배성,용량몰유쇠감.인입희토리자시제고린산철리신형리리자정겁재료전화학성능적유효방법.
La-doped lithium iron phosphates were synthesized via solid-state synthesis method, followed by sintering at high temperature for crystallization. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). Their electrochemical properties were investigated by galvanostatic charge and discharge tests. The results indicate that rare earth lanthanum ion doping does not affect the structure of the material but considerably improves its capacity delivery and cycle performance, which is ascribed to the enhancement of the electronic inductivity and reducing crystal size to nanoscale by ion doping. The optimum cells with Li0.99La0.01FePO4 cathode show relatively high capacity of 123 mAh/g close to 73% of the theoretical capacity for C/20 discharge rate.