Two-dimensional biomass-derived carbon nanosheets and MnO/carbon electrodes for high-performance Li-ion capacitors
By Zhao, Yuemei; Cui, Yongpeng; Shi, Jing; Liu, Wei; Shi, Zhicheng; Chen, Shougang; Wang, Xin; Wang, Huanlei
Published in J. Mater. Chem. A
2017
Abstract
Li-ion capacitors have been considered as next-generation advanced energy storage systems to meet the requirements of both high energy and high power due to the combination of rapid and long-term charge storage of supercapacitors and the high energy storage capacity of lithium ion batteries. Herein, we demonstrate the design of 2D nanostructured electrodes from low-cost biomass-kapok fiber for Li-ion capacitors: 2D carbon nanosheets with a high surface area and hierarchical porosity for the positive electrode, and 2D MnO/C nanocomposites with a large surface area and nanosized particles for the negative electrode. With the benefit of the structure of the Li-ion capacitor, the hybrid device can be operated at a high operating voltage of 4[space]V, exhibiting a high energy density of 100 W h kg-1 at 83 W kg-1, a high power density of 20 kW kg-1 at 30 W h kg-1 based on the active materials, and a capacity retention ratio of 70% after 5000 cycles. These results clearly demonstrate that biomass-derived electrodes are potential candidates for low-cost, fast and efficient energy storage systems in the future.