Potassium metal is an ideal anode for potassium-metal batteries due to its low electrode potential and high theoretical capacity. Nevertheless, infinite volume change, uncontrollable K dendrite growth, and unstable solid-electrolyte interfaces severely restrain its practical viability. Inspired by the vertical channels in natural wood, a spatial control strategy is proposed to address the above challenges using a low-tortuosity carbon matrix decorated with single-atom Co catalysts that act as K hosts (denoted as SA-Co@HC). The homogenously supported Co atoms on the nitrogen-doped carbon matrix reduce the nucleation energy barrier and promote the deposition kinetics of K. Furthermore, the conductive low-tortuosity matrix can alter the electric field and allow fast K-ion transport in the vertical direction. More importantly, the SA-Co@HC host provides sufficient channel spaces to withstand the tremendous electrode volume change upon cycling. Benefitting from the synergetic effects of the SA-Co@HC host, the symmetric cell using a SA-Co@HC/K composite electrode demonstrates a dendrite-free potassium plating/striping behavior, as well as achieving superb cycling stability of more than 2500 h at 0.5 mA cm⁻² in a carbonate-based electrolyte. The full cell coupled with potassium-free organic cathodes, the SA-Co@HC/K composite anode helps deliver excellent cycle and rate performances compared to the bare K anode.

中文翻译：

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将低曲折度碳基质与单原子化学偶联可实现无枝晶钾金属阳极

钾金属由于其低电极电位和高理论容量而成为钾金属电池的理想负极。然而，无限大的体积变化、不可控的 K 枝晶生长和不稳定的固体电解质界面严重限制了其实际可行性。受天然木材中垂直通道的启发，提出了一种空间控制策略来解决上述挑战，使用装饰有作为 K 主体的单原子 Co 催化剂的低曲折度碳矩阵（表示为 SA-Co@HC）。氮掺杂碳基体上均匀负载的 Co 原子降低了成核能垒并促进了 K 的沉积动力学。此外，导电的低曲折度基体可以改变电场并允许 K 离子在垂直方向上快速传输。更重要的是，SA-Co@HC 主体提供了足够的通道空间来承受循环时巨大的电极体积变化。受益于 SA-Co@HC 主体的协同效应，使用 SA-Co@HC/K 复合电极的对称电池表现出无枝晶的钾电镀/剥离行为，并实现了超过 2500 次的出色循环稳定性h 在 0.5 毫安厘米^-2在基于碳酸盐的电解质中。全电池与无钾有机阴极相结合，SA-Co@HC/K 复合阳极与裸 K 阳极相比有助于提供出色的循环和倍率性能。