Qiu Chuang, Li Min, Qiu Daping, Yue Cheng, Xian Liying, Liu Shiqiang, Wang Feng, Yang Ru
State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing 100029, China.
Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
ACS Appl Mater Interfaces. 2021 Oct 27;13(42):49942-49951. doi: 10.1021/acsami.1c14314. Epub 2021 Oct 13.
Sulfur doping is a promising path to ameliorate the kinetics of carbon-based anodes. However, the similar electronegativity of sulfur and carbon and the poor thermal stability of sulfur severely restrict the development of high-sulfur-content carbon-based anodes. In this work, ultra-high sulfur-doped hierarchical porous hollow carbon spheres (SHCS) with a sulfur content of 6.8 at % are synthesized via a direct high-temperature sulfur-doping strategy. An SHCS has sulfur bonded to the carbon framework including C-S-C and C-SO-C, which enlarges its interlayer distance (0.411 nm). In the K half-cell, benefiting from the considerable content and the reasonable architecture of sulfur, the SHCS exhibits significantly improved reversible specific capacity, initial Coulombic efficiency, and cyclability than hierarchical porous hollow carbon spheres without sulfur. Remarkably, the potassium ion hybrid capacitor device fabricated with the SHCS anode achieves excellent energy/power density (135.6 W h kg/17.7 kW kg) and unprecedented durability over 26,000 cycles at 2 A g. This research provides a superior strategy to design high-sulfur-content carbon-based anodes with excellent potassium storage performance.
硫掺杂是改善碳基负极动力学的一条有前景的途径。然而，硫与碳相近的电负性以及硫较差的热稳定性严重限制了高硫含量碳基负极的发展。在这项工作中，通过直接高温硫掺杂策略合成了硫含量为6.8 at%的超高硫掺杂分级多孔空心碳球（SHCS）。一个SHCS具有与碳骨架键合的硫，包括C-S-C和C-SO-C，这扩大了其层间距（0.411 nm）。在钾半电池中，得益于硫的可观含量和合理结构，SHCS比不含硫的分级多孔空心碳球表现出显著提高的可逆比容量、初始库仑效率和循环稳定性。值得注意的是，用SHCS负极制造的钾离子混合电容器器件在2 A g下实现了优异的能量/功率密度（135.6 W h kg/17.7 kW kg）以及超过26,000次循环的前所未有的耐久性。这项研究为设计具有优异储钾性能的高硫含量碳基负极提供了一种卓越的策略。
