Zhao Tianyu, Yang Dongzhi, Xu Ting, Zhang Ming, Zhang Shiyi, Qin Liyuan, Yu Zhong-Zhen
State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
Chemistry. 2021 Feb 15;27(10):3473-3482. doi: 10.1002/chem.202004703. Epub 2021 Jan 25.
Although graphene fiber-based supercapacitors are promising for wearable electronic devices, the low energy density of electrodes and poor cold resistance of aqueous electrolytes limit their wide application in cold environments. Herein, porous nitrogen/sulfur dual-doped graphene fibers (NS-GFs) are synthesized by hydrothermal self-assembly followed by thermal annealing, exhibiting an excellent capacitive performance of 401 F cm at 400 mA cm because of the synergistic effect of heteroatom dual-doping. The assembled symmetric all-solid-state supercapacitor with polyvinyl alcohol/H SO /graphene oxide gel electrolyte exhibits a high capacitance of 221 F cm and a high energy density of 7.7 mWh cm at 80 mA cm . Interestingly, solar-thermal energy conversion of the electrolyte with 0.1 wt % graphene oxide extends the operating temperature range of the supercapacitor to 0 °C. Furthermore, the photocatalysis effect of the dual-doped heteroatoms increases the capacitance of NS-GFs. At an ambient temperature of 0 °C, the capacitance increases from 0 to 182 F cm under 1 sun irradiation because of the excellent solar light absorption and efficient solar-thermal energy conversion of graphene oxide, preventing the aqueous electrolyte from freezing. The flexible supercapacitor exhibits a long cycle life, good bending resistance, reliable scalability, and ability to power visual electronics, showing great potential for outdoor electronics in cold environments.
尽管基于石墨烯纤维的超级电容器在可穿戴电子设备方面前景广阔，但电极的低能量密度和水性电解质较差的耐寒性限制了它们在寒冷环境中的广泛应用。在此，通过水热自组装随后进行热退火合成了多孔氮/硫双掺杂石墨烯纤维（NS-GFs），由于杂原子双掺杂的协同效应，在400 mA cm时表现出401 F cm的优异电容性能。采用聚乙烯醇/H₂SO₄/氧化石墨烯凝胶电解质组装的对称全固态超级电容器在80 mA cm时具有221 F cm的高电容和7.7 mWh cm的高能量密度。有趣的是，含0.1 wt%氧化石墨烯的电解质的太阳能-热能转换将超级电容器的工作温度范围扩展到了0°C。此外，双掺杂杂原子的光催化效应增加了NS-GFs的电容。在0°C的环境温度下，由于氧化石墨烯具有优异的太阳光吸收和高效的太阳能-热能转换能力，防止了水性电解质冻结，在1个太阳光照下电容从0增加到182 F cm。这种柔性超级电容器具有长循环寿命、良好的抗弯曲性、可靠的可扩展性以及为可视化电子设备供电的能力，在寒冷环境中的户外电子产品方面显示出巨大潜力。
