Despite the high potassium-ion storage of chalcogenide anodes relative to intercalation-based graphite, inhibition of their large volume change during the potassiation/depotassiation process, and stabilization of reversible electrochemical reactions to ensure efficient electron/ion transfer remain challenging. Here we report composition-tunable ternary chalcogenides that achieve highly reversible potassium-ion storage through synergistic interactions between elements. A series of Bi_2−xSb_xSe₃ ternary chalcogenide (x = 0, 0.25, 1, 1.75, 2) solid solutions with a full composition range are designed using a facile high energy mechanical milling method. Sb₂Se₃ substituted by Bi gives rise to a chemical bond softening effect that accompanies structural transition and maintains excellent structural stability. Meanwhile, the intermediate quaternary-phase K₃(Bi,Sb)Se₃ enables a highly reversible 12-electron transfer conversion/alloying reaction during the potassiation/depotassiation process. Various electrochemical analyses show that Bi_2−xSb_xSe₃ inherits the advantages of binary Sb₂Se₃ (high capacity) and Bi₂Se₃ (stability) while balancing their respective disadvantages, confirming the synergistic effect of ternary chalcogenide systems. By engineering Bi_2−xSb_xSe₃ implemented into potassium-ion based full cells, we demonstrate a high energy/power density of 76.9 W h kg⁻¹/1964.2 W kg⁻¹ for batteries and 54.3 W h kg⁻¹/3685.7 W kg⁻¹ for hybrid capacitors. This work illustrates how to exploit the underlying multilateral science and the relevant electrochemistry of ternary chalcogenides to achieve excellent electrochemical performance, suggesting a new avenue of anode design for potassium-ion storage.

尽管硫属化物阳极相对于插层石墨具有较高的钾离子存储能力，但在钾化/去钾过程中抑制其较大的体积变化以及稳定可逆电化学反应以确保有效的电子/离子转移仍然具有挑战性。在这里，我们报告了组成可调的三元硫属化物，它们通过元素之间的协同相互作用实现了高度可逆的钾离子存储。使用简便的高能机械研磨方法设计了一系列具有全成分范围的Bi _2−x Sb _x Se _{3三元硫属化物（x = 0, 0.25, 1, 1.75, 2）固溶体。}锑₂硒₃被Bi取代产生伴随结构转变并保持优异结构稳定性的化学键软化作用。同时，中间四元相 K ₃ (Bi,Sb)Se ₃在钾化/去钾化过程中实现了高度可逆的 12 电子转移转化/合金化反应。各种电化学分析表明，Bi _2−x Sb _x Se ₃继承了二元 Sb ₂ Se ₃（高容量）和 Bi ₂ Se ₃（稳定性）的优点，同时平衡了它们各自的缺点，证实了三元硫属化物系统的协同效应。由工程毕_2−x Sb _x Se ₃应用于基于钾离子的全电池中，我们展示了电池的 76.9 W h kg ^-1 /1964.2 W kg ^-1和 54.3 W h kg ^-1 /3685.7 W kg的高能量/功率密度^-1用于混合电容器。这项工作说明了如何利用潜在的多边科学和三元硫属化物的相关电化学来实现优异的电化学性能，为钾离子存储的阳极设计提供了一条新途径。