Chen Hong, Qiu Nan, Wu Baozhen, Yang Zhaoming, Sun Sen, Wang Yuan
Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University Chengdu 610064 People's Republic of China
RSC Adv. 2019 Sep 13;9(50):28908-28915. doi: 10.1039/c9ra05508h.
Ultrafine crystalline materials have been extensively investigated as high-rate lithium-storage materials due to their shortened charge-transport length and high surface area. The pseudocapacitive effect plays a considerable role in electrochemical lithium storage when the electrochemically active materials approach nanoscale dimensions, but this has received limited attention. Herein, a series of (MgCoNiCuZn)O electrodes with different particle sizes were prepared and tested. The ultrafine (MgCoNiCuZn)O nanofilm (3-5 nm) anodes show a remarkable rate capability, delivering high specific charge and discharge capacities of 829, 698, 602, 498 and 408 mA h g at 100, 200, 500, 1000 and 2000 mA g, respectively, and a dominant pseudocapacitive contribution as high as 90.2% toward lithium storage was revealed by electrochemical analysis at a high scanning rate of 1.0 mV s. This work offers an approach to tune the lithium-storage properties of (MgCoNiCuZn)O by size control and gives insights into the enhancement of pseudocapacitance-assisted lithium-storage capacity.
由于其缩短的电荷传输长度和高比表面积，超细晶体材料作为高倍率锂存储材料受到了广泛研究。当电化学活性材料接近纳米尺度时，赝电容效应在电化学锂存储中起着相当重要的作用，但这方面受到的关注有限。在此，制备并测试了一系列不同粒径的(MgCoNiCuZn)O电极。超细(MgCoNiCuZn)O纳米薄膜(3 - 5纳米)阳极显示出显著的倍率性能，在100、200、500、1000和2000 mA g时分别提供829、698、602、498和408 mA h g的高比充放电容量，并且在1.0 mV s的高扫描速率下通过电化学分析揭示了高达90.2%的主导赝电容对锂存储的贡献。这项工作提供了一种通过尺寸控制来调节(MgCoNiCuZn)O锂存储性能的方法，并深入了解了赝电容辅助锂存储容量的增强。
