X射线衍射Rietveld精修及其在锂离子电池正极材料中的应用

杨卓, 卢勇, 赵庆, 陈军

X-ray Diffraction Rietveld Refinement and Its Application in Cathode Materials for Lithium-ion Batteries

YANG Zhuo, LU Yong, ZHAO Qing, CHEN Jun

表2 LiFePO4和LiFe0.95M0.05PO4的结构精修结果[62]

Table 2 Structure refinement result of LiFePO4 and LiFe0.95M0.05PO4 (M=Mg2+, Ni2+, Al3+, V3+) (© 2010, EC)[62]

Sample Doped atomic radius/nm Displace ion radius/nm Lattice constant/nm Lattice volume/nm3 Interatomic distance/nm Reliability factor LFP rFe = 0.172 rFe2+ = 0.074 a=1.031634 b=0.600129 c=0.469139 0.29045 Li-O1:0.21664 Li-O2:0.20901 Li-O3:0.21651 Li-O:0.214050 Rwp = 7.72% Rp =5.63% χ2 = 2.794 LFMgP rMg = 0.172 rMg2+ = 0.065 a=1.031583 b=0.600035 c=0.469090 0.29036 Li-O1:0.21712 Li-O2:0.21041 Li-O3:0.21665 Li-O:0.214720 Rwp = 9.32% Rp = 6.79% χ2 = 2.878 LFAlP rAl = 0.182 rAl3+ = 0.050 a=1.032204 b=0.600358 c=0.469072 0.29068 Li-O1:0.21670 Li-O2:0.21001 Li-O3:0.21747 Li-O:0.214730 Rwp = 9.14% Rp = 6.60% χ2 = 2.989 LFNiP rNi = 0.162 rNi2+ = 0.072 a=1.031083 b=0.599820 c=0.468923 0.29001 Li-O1:0.21734 Li-O2:0.20863 Li-O3:0.21586 Li-O:0.213950 Rwp = 8.26% Rp = 6.12% χ2= 2.929 LFVP rV = 0.192 rV3+ = 0.074 a=1.032223 b=0.600494 c=0.469485 0.291 Li-O1:0.21864 Li-O2:0.21074 Li-O3:0.21794 Li-O:0.215770 Rwp = 9.86% Rp = 7.15% χ2= 2.426