
UiO-66金属团簇和缺陷对锂硫电池隔膜电化学性能的影响
赵瑛妹, 赵玉青, 周星宇, 李海鑫, 程琥, 庄金亮
UiO-66金属团簇和缺陷对锂硫电池隔膜电化学性能的影响
Effects of UiO-66 metal clusters and defects on electrochemical performances of lithium-sulfur battery separators
分别以硝酸铈铵(Ce(NH4)2(NO3)6)和四氯化锆(ZrCl4)为金属盐,1,4-对苯二甲酸为有机配体(H2BDC),合成Ce-UiO-66和Zr-UiO-66两种金属有机框架(MOFs)。通过粉末X射线衍射(XRD)、扫描电子显微镜(SEM)等技术表征MOFs的晶体结构和形貌。采用真空抽滤法将Ce-UiO-66和Zr-UiO-66负载于Celgard PP商用隔膜一侧,制备MOFs修饰的功能性隔膜,组装并测试锂硫电池的电化学性能。结果表明:Ce-UiO-66改性隔膜电池具有最优的电化学性能,在0.2 C倍率下,首圈放电容量为1047 mAh·g-1,经200周次循环后,容量保持率为77.5%,库仑效率接近100%。在不同倍率循环下,Ce-UiO-66改性隔膜电池在0.1、0.2、0.5、1、2 C倍率下的放电容量分别达到1281、945、768.1、673.2、604.7 mAh·g-1,当返回至0.1 C时,容量恢复至951.6 mAh·g-1,容量保持率为74.3%。上述表明Ce-UiO-66中的氧化还原活性Ce6-oxo团簇可有效催化多硫化锂的转化反应,改善氧化还原动力学性能;此外,Ce-UiO-66还存在较多缺陷和不饱和配位点,能够有效锚定多硫化锂(LiPSs),减缓多硫化物穿梭效应,进一步提升电池的电化学性能。
Two metal-organic frameworks (MOFs), Ce-UiO-66, and Zr-UiO-66, are synthesized using cerium ammonium nitrate (Ce(NH4)2(NO3)6) and zirconium tetrachloride (ZrCl4) as metal salts, and 1,4-benzenedicarboxylic acid (H2BDC) as the organic linker. The crystal structure and morphology of the MOFs are characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The MOFs-modified functional separators are prepared by loading Ce-UiO-66 and Zr-UiO-66 onto one side of commercial Celgard PP separators via vacuum filtration. The electrochemical performance of lithium-sulfur batteries is assembled and tested. The results show that the Ce-UiO-66 modified separator batteries demonstrates optimal electrochemical performance. At a rate of 0.2 C, the initial discharge capacity reaches 1047 mAh·g-1, with a capacity retention rate of 77.5% after 200 cycles and Coulombic efficiency approaching 100%. Under various current rates, the Ce-UiO-66 modified cells deliver discharge capacities of 1281, 945, 768.1, 673.2, 604.7 mAh·g-1 at 0.1, 0.2, 0.5, 1, 2 C, respectively. When returning to 0.1 C, the capacity recovers to 951.6 mAh·g-1 with a capacity retention rate of 74.3%. The above results demonstrate that the redox-active Ce₆-oxo clusters in Ce-UiO-66 can effectively catalyze the conversion reactions of lithium polysulfides (LiPSs) and enhance the redox kinetics. Furthermore, Ce-UiO-66 possesses abundant defects and unsaturated coordination sites, which can effectively anchor LiPSs, mitigate the shuttle effect, and further enhance the electrochemical performance of batteries.
锂硫电池 / 金属有机框架 / 隔膜 / 多硫化物 / 穿梭效应
lithium-sulfur battery / metal-organic framework / separator / polysulfide / shuttle effect
TQ152
[1] |
|
[2] |
赵基钢, 王赫, 郑俊生. 锂离子电容器正极材料的研究进展[J].材料工程, 2023, 51(9): 28-36.
|
[3] |
|
[4] |
|
[5] |
|
[6] |
|
[7] |
|
[8] |
|
[9] |
|
[10] |
|
[11] |
庄金亮, 薛云, 申妍铭, 等.液相外延法制备金属-有机骨架薄膜及其应用[J]. 贵州师范大学学报(自然科学版), 2020, 38(5): 104-118.
|
[12] |
|
[13] |
|
[14] |
|
[15] |
|
[16] |
|
[17] |
|
[18] |
|
[19] |
|
[20] |
|
[21] |
|
[22] |
|
[23] |
|
[24] |
|
[25] |
|
[26] |
|
[27] |
|
[28] |
|
[29] |
|
[30] |
|
[31] |
|
[32] |
|
/
〈 |
|
〉 |