Cu^2＋掺杂LiFePO4的制备及其电化学性能

Cu Doping LiFePO_4 and its Electrochemical Performance

应用固相反应法合成LiFePO4及掺杂Cu2+的LiFePO4,以XRD、XPS表征样品的结构及Fe存在的价态.发现掺杂少量的Cu2+未能改变LiFePO4材料的结构特征以及Fe2+的化学状态,但是Cu2+的掺杂使得LiFePO4材料的晶胞体积变小.充放电测试结果表明少量Cu2+的掺杂能显著地提高LiFePO4材料的大倍率输出能力,LiCu0.02Fe0.98PO4,其1C放电容量可达130 mAh/g以上,较掺杂前提高了20%左右.

LiFePO4 and LiFePO4 doped with Cu^2＋ ions were synthesized by sohd-state reactions. The structure of LiFePO4 and the Fe valence were analyzed by the XRD （ X-ray diffraction） and XPS （ X-ray photoelectron spectroscopy） respectively. The Cu doping position in LiFePO4 is discussed. It has found that the volume of LiFePO4 by doping Cu^2＋ ions is reduced. The minim Cu^2＋ ions doping does not almost change the binding energy of Fe2p1/2 in LiFePO4. According to the experiment results, we conclude that most of the Cu^2＋ ions substitute the Fe^2＋ ions in LiFePO4 when a small amount of Cu^2＋ ions doping is occurred.