Hu Pinfei, Meng Chunfeng, Li Fanggang, Wang Ping, Zhou Hu, Li Xiaogang, Yuan Aihua
School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003, P. R. China.
School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, P. R. China.
J Colloid Interface Sci. 2022 Jul;617:568-577. doi: 10.1016/j.jcis.2022.02.134. Epub 2022 Mar 1.
The capacity attenuation of transition metal oxides (TMOs) and metal-organic frameworks (MOFs) is the obstacle for practical application in lithium ion batteries, due to the extensive volume variation upon charge/discharge cycles. Herein, a hierarchical composite material with copper oxide (CuO) multi-yolks and copper-1, 3, 5-benzenetricarboxylate (Cu-BTC) shell is synthesized by a facile method to study the effect of the hierarchical structure on the electrochemical performance. The porosity and pore volume of CuO@Cu-BTC composites are optimized to buffer the volume change and facilitate the infiltration of electrolytes by altering reaction conditions. The CuO@Cu-BTC (20 h) with the largest surface area and pore volume delivers an excellent reversible capacity of 780.7 mAh g at 200 mA g after 100 cycles, and ultrastable long-term performance with a specific capacity of 569 mAh g at a current density of 1000 mA g after 900 cycles. The corresponding full battery shows moderate capacity retention from 149.4 to 125.8 mAh g after 70 cycles, with a specific capacity retention of 84.2%, based on the mass of lithium iron phosphate (LiFePO) at 0.2 C (1 C = 170 mA g). This strategy applies copper oxide as the metal source of the coordination compound, as well as the internal yolks, which can be extended to the in-situ construction of other hierarchical composites, providing a new avenue for practical application of TMOs and MOFs as anode materials.
过渡金属氧化物（TMOs）和金属有机框架（MOFs）的容量衰减是其在锂离子电池中实际应用的障碍，这是由于在充放电循环过程中会发生大幅度的体积变化。在此，通过一种简便的方法合成了一种具有氧化铜（CuO）多蛋黄和1,3,5-苯三甲酸铜（Cu-BTC）壳层的分级复合材料，以研究分级结构对电化学性能的影响。通过改变反应条件，优化了CuO@Cu-BTC复合材料的孔隙率和孔体积，以缓冲体积变化并促进电解质的渗透。具有最大表面积和孔体积的CuO@Cu-BTC（20 h）在100次循环后，在200 mA g下具有780.7 mAh g的优异可逆容量，在900次循环后，在1000 mA g的电流密度下具有569 mAh g的超稳定长期性能。相应的全电池在70次循环后显示出适度的容量保持率，从149.4 mAh g降至125.8 mAh g，基于磷酸铁锂（LiFePO）在0.2 C（1 C = 170 mA g）下的质量，比容量保持率为84.2%。该策略将氧化铜用作配位化合物的金属源以及内部蛋黄，这可以扩展到其他分级复合材料的原位构建，为TMOs和MOFs作为阳极材料的实际应用提供了一条新途径。
