Potassium-sulfur electrochemistry represents a compelling energy storage technology due to its cost-efficient chemicals and unparalleled capacity. However, achieving high sulfur redox utilization (SRU) remains a great challenge during K⁺ storage due to K₂S_n kinetics inertia. Here, for the first time, we unveil an aqueous K⁺-S electrochemistry, leveraging boosted K₂S_n conversion kinetics in water. A stable two-electron charge transfer process is achieved via tuning K₂S solubility. Spectroscopic evaluation and molecular dynamics simulations reveal a unique solid-liquid-solid conversion pathway (S ↔ K₂S₄ ↔ K₂S), which effectively avoids soluble K₂S shuttling. Consequently, an unprecedented K⁺ storage capacity of 1,619 mAh g⁻¹ (ca. 96% SRU) can be achieved with 95% initial Coulombic efficiency, appealing cyclability over 500 times, and a high-energy density of 392 Wh kg_S+Zn⁻¹. These findings signify a paradigm shift and introduce transformative opportunities for the design of safe and high-energy aqueous batteries.

钾硫电化学因其具有成本效益的化学品和无与伦比的容量而代表了一种引人注目的储能技术。然而，由于K ₂ S _n动力学惯性，在K ⁺存储过程中实现高硫氧化还原利用率（SRU）仍然是一个巨大的挑战。在这里，我们首次推出了水性 K ⁺ -S 电化学，利用水中增强的 K ₂ S _{n转化动力学。通过调节K 2} S溶解度实现稳定的双电子电荷转移过程。光谱评估和分子动力学模拟揭示了独特的固-液-固转化途径(S ↔ K ₂ S ₄ ↔ K ₂ S)，有效避免了可溶性K ₂ S穿梭。因此，可以实现前所未有的 1,619 mAh g ⁻¹（约96% SRU）的 K ⁺存储容量、 95% 的初始库仑效率、超过 500 次的循环性能以及 392 Wh kg _{S+Zn的高能量密度}⁻¹。这些发现标志着范式的转变，并为安全和高能水电池的设计带来了变革性的机会。