锂硫电池正极材料Al-ABTC/RGO@S的制备及电化学性能

Preparation and Electrochemical Performance of Al-ABTC/RGO@S as Cathode Material for Lithium-Sulfur Battery

通过溶剂热法制备了一种高比表面积的铝基金属有机框架(metal organic frameworks,MOFs)材料Al-ABTC。然后通过静电吸附法将Al-ABTC与氧化石墨烯(GO)复合,并载硫得到Al-ABTC/RGO@S复合材料用于锂硫电池。采用X射线衍射(XRD)分析了Al-ABTC的晶体结构,采用扫描电镜(SEM)对Al-ABTC、Al-ABTC/GO和Al-ABTC/RGO@S的八面体形貌进行表征,用恒流充放电测试材料的电化学性能。结果表明,Al-ABTC/RGO@S复合电极在0.2 C倍率下的首次放电比容量达到1345.3 mAh·g^(-1),经过200次的循环以后还能达到406.4 mAh·g^(-1)的比容量,其平均库伦效率为99.1%。此外,电池即使在2 C下,首次放电比容量也高达714.7 mAh·g^(-1),经过300次循环以后比容量仍能保持在331 mAh·g^(-1),表现出良好的长循环性能。

A high specific surface area Al-based metal organic frameworks(MOFs) material Al-ABTC was prepared by hydrothermal synthesis. Then the Al-ABTC and graphene oxide(GO) were compounded by electrostatic adsorption method, and sulfur was loaded to obtain Al-ABTC/RGO@S composite material for lithium-sulfur battery. The crystal structure of Al-ABTC was analyzed by X-ray diffraction(XRD), the octahedral morphology of Al-ABTC, Al-ABTC/GO and Al-ABTC/RGO@S was characterized by scanning electron microscope(SEM), and the electrochemical performance of the material was tested by constant current charge and discharge. The results show that the initial specific discharge capacity of the Al-ABTC/RGO@S composite electrode reaches 1345.3 mAh·g^(-1)at 0.2 C, and then the specific capacity decays to 406.4 mAh·g^(-1) after 200 cycles, and the average coulombic efficiency is 99.1%. In addition, even at 2 C, an initial reversible specific capacity of 714.7 mAh·g^(-1) is received and a specific capacity of 331 mAh·g^(-1)after 300 cycles is retained,showing an excellent long-term cycling performance.