CeO_(2)-C复合空心球改性硫正极的电化学性能

Modification of sulfur cathode by CeO_(2)-C composite hollow spheres and research on electrochemical performance

本文以酚醛树脂(APF)和六水合硝酸铈(Ce(NO_(3))_(3)·6H_(2)O)为原料,采用无溶剂模板法制备CeO_(2)-C复合空心球,并通过X射线衍射仪、扫描电子显微镜、透射电子显微镜、傅里叶红外光谱等测试方法对其进行表征。以商业化导电碳黑作为硫载体,将CeO_(2)-C复合空心球作为添加剂改性硫正极材料,并进行循环伏安(CV)、恒电流充放电、电化学阻抗(EIS)等电化学性能测试。结果表明:CeO_(2)-C复合空心球改性后的硫正极材料具有较好的电化学性能,其在0.2C下的初始放电容量可达到1 125 mAh/g;在1C下循环500圈,每圈的容量损失率仅为0.083%。以商业化导电碳黑作为硫载体,通过添加少量CeO_(2)-C复合空心球改性剂制备硫正极,能够在不改变目前锂硫电池制备工艺的前提下,有效提升锂硫电池的电化学性能,显示出巨大的应用潜力。

CeO_(2)-C composite hollow spheres materials were synthesized by solvent-free template method using 3-aminophenol formaldehyde(APF) resin spheres and cerium nitrate hexahydrate(Ce(NO_(3))_(3)·6H_(2)O) as raw materials.The as-prepared samples were characterized by X-raydiffractometer(XRD), scanning electron microscope(SEM),transmission electron microscope(TEM), Fourier infrared spectroscopy(FTIR), etc. In addition, commercial conductive carbon black was used as the sulfur host material, and the prepared CeO_(2)-C composite hollow spheres were used as an additive to modify the sulfur cathode material. The electrochemical performance of the modified sulfur cathode material was tested by cyclic voltammetry(CV), galvanostatic charge-discharge(GCD), electrochemical impedance(EIS), etc.The results show that the sulfur cathodes modified by CeO_(2)-C composite hollow spheres exhibit higher initial discharge capacity of 1 125 mAh/g at 0.2 C, and the lower capacity decay rate of 0.083% per cycle at 1 C after 500 cycles. Using commercial conductive carbon black as sulfur carrier and adding a small amount of CeO_(2)-Ccomposite hollow sphere modifier to prepare sulfur cathode can effectively improve the electrochemical performance of lithium sulfur battery without changing the current preparation process of lithium sulfur battery, showing great application potential.