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_x–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^–1/17.7 kW kg^–1) and unprecedented durability over 26,000 cycles at 2 A g^–1. This research provides a superior strategy to design high-sulfur-content carbon-based anodes with excellent potassium storage performance.

中文翻译：

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超高硫掺杂分层多孔空心碳球阳极实现前所未有的耐用钾离子混合电容器

硫掺杂是改善碳基阳极动力学的一条有前途的途径。然而，硫和碳相似的电负性以及硫的热稳定性差严重制约了高硫碳基负极的发展。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)。SHCS 具有与碳骨架结合的硫，包括 C-S-C 和 C-SO _x-C，增大了其层间距离（0.411 nm）。在 K 半电池中，得益于硫的大量含量和合理的结构，与不含硫的分级多孔空心碳球相比，SHCS 表现出显着提高的可逆比容量、初始库仑效率和循环性能。值得注意的是，用 SHCS 阳极制造的钾离子混合电容器装置实现了出色的能量/功率密度（135.6 W h kg ^–1 /17.7 kW kg ^–1）和在 2 A g ^{–1 下}超过 26,000 次循环的前所未有的耐用性。该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优越的策略。