Zhang Xiaoyu, Ma Ge, Shui Lingling, Zhou Guofu, Wang Xin
South China Academy of Advanced Optoelectronics & International Academy of Optoelectronics at Zhaoqing, South China Normal University, Guangdong 510631, P. R. China.
ACS Appl Mater Interfaces. 2021 Jan 27;13(3):4419-4428. doi: 10.1021/acsami.0c21330. Epub 2021 Jan 12.
Ultrathin CoO nanosheets (NSs) with abundant oxygen vacancies on conductive carbon nanotube (CNT) nanocomposites (termed as CoO-NSs/CNTs) are easily achieved by an effective NaBH-assisted cyanogel hydrolysis strategy under ambient conditions. The specific capacitance of CoO-NSs/CNTs with 5% CNT mass can reach 1280.4 F g at 1 A g and retain 112.5% even after 10 000 cycles, demonstrating very high electrochemical capability and stability. When assembled in the two-electrode CoO-NSs/CNTs-5%//reduced graphene oxide (rGO) system, a maximum specific energy density of 37.2 Wh kg (160.2 W kg) is obtained at room temperature. Ultrathin structure of nanosheets, abundant oxygen vacancies, and the synergistic effect between CoO-NSs and CNTs are crucial factors for excellent electrochemical performance. Specifically, these characteristics favor rapid electron transfer, complete exposure of the active interface, and sufficient adsorption/desorption of electrolyte ions within the active material. This work gives insights into the efficient construction of two-dimensional hybrid electrodes with high performance for the new-generation energy storage system.
通过在环境条件下采用有效的硼氢化钠辅助氰基凝胶水解策略，可轻松制备出在导电碳纳米管（CNT）纳米复合材料（称为CoO-NSs/CNTs）上具有大量氧空位的超薄氧化钴纳米片（NSs）。质量分数为5% CNT的CoO-NSs/CNTs在1 A g下的比电容可达1280.4 F g，即使在10000次循环后仍保持112.5%，展现出非常高的电化学性能和稳定性。当组装成两电极CoO-NSs/CNTs-5%//还原氧化石墨烯（rGO）体系时，在室温下可获得37.2 Wh kg（160.2 W kg）的最大比能量密度。纳米片的超薄结构、丰富的氧空位以及CoO-NSs与CNTs之间的协同效应是实现优异电化学性能的关键因素。具体而言，这些特性有利于快速电子转移、活性界面的完全暴露以及活性材料内电解质离子的充分吸附/解吸。这项工作为新一代储能系统高效构建高性能二维混合电极提供了思路。
