CAJ | 학술논문

固相法合成具有橄榄石型结构的LiFePO_4晶体,合成温度分别为670、700、730℃.采用XRD结构精修对合成LiFePO_4的结构进行了研究.研究发现随着合成温度的变化,晶胞参数a、b和c发生变化,晶胞参数的变化是等比例的增加或减少.由于合成温度的变化,Fe-O八面体中Fe-O键长发生变化,Fe-O键长的变化将会使得Fe的3 d轨道能量发生变化.相对于合成温度670、730℃,在700℃合成的LiFePO_4晶体具有最大的锂离子扩散有效面积.
고상법합성구유감람석형결구적LiFePO_4정체,합성온도분별위670、700、730℃.채용XRD결구정수대합성LiFePO_4적결구진행료연구.연구발현수착합성온도적변화,정포삼수a、b화c발생변화,정포삼수적변화시등비례적증가혹감소.유우합성온도적변화,Fe-O팔면체중Fe-O건장발생변화,Fe-O건장적변화장회사득Fe적3 d궤도능량발생변화.상대우합성온도670、730℃,재700℃합성적LiFePO_4정체구유최대적리리자확산유효면적.
LiFePO_4 was prepared by solid state reaction, which the synthesizing temperature was 670, 700 ℃ and 730 ℃. LiFePO_4 crystalline structure was studied by Rietveld refinement. The research shows that the lattice parameter change with the temperature changing and the changing of the lattice parameters are almost proportioned. With the temperature changing, the Fe-O bond length changed, which makes the energy of 3 d orbit of Fe change. Compared with the synthesizing temperature of 670 ℃ or 730 ℃, the effective cross-section of LiFePO_4 in 700 ℃ is larger.