The development of durable and stable metal oxide anodes for potassium ion batteries (PIBs) has been hampered by poor electrochemical performance and ambiguous reaction mechanisms. Herein, we design and fabricate molybdenum dioxide (MoO₂)@N-doped porous carbon (NPC) nano-octahedrons through metal–organic frameworks derived strategy for PIBs with MoO₂ nanoparticles confined within NPC nano-octahedrons. Benefiting from the synergistic effect of nanoparticle level of MoO₂ and N-doped carbon porous nano-octahedrons, the MoO₂@NPC electrode exhibits superior electron/ion transport kinetics, excellent structural integrity, and impressive potassium-ion storage performance with enhanced cyclic stability and high-rate capability. The density functional theory calculations and experiment test proved that MoO₂@NPC has a higher affinity of potassium and higher conductivity than MoO₂ and N-doped carbon electrodes. Kinetics analysis revealed that surface pseudocapacitive contributions are greatly enhanced for MoO₂@NPC nano-octahedrons. In-situ and ex-situ analysis confirmed an intercalation reaction mechanism of MoO₂@NPC for potassium ion storage. Furthermore, the assembled MoO₂@NPC//perylenetetracarboxylic dianhydride (PTCDA) full cell exhibits good cycling stability with 72.6 mAh g⁻¹ retained at 100 mA g⁻¹ over 200 cycles. Therefore, this work present here not only evidences an effective and viable structural engineering strategy for enhancing the electrochemical behavior of MoO₂ material in PIBs, but also gives a comprehensive insight of kinetic and mechanism for potassium ion interaction with metal oxide.

用于钾离子电池 (PIB) 的耐用且稳定的金属氧化物阳极的开发受到电化学性能差和反应机制不明确的阻碍。在此，我们通过金属有机框架衍生的 PIB 策略设计和制造二氧化钼 (MoO ₂ )@ N掺杂的多孔碳 (NPC) 纳米八面体，其中 MoO ₂纳米颗粒限制在 NPC 纳米八面体中。受益于纳米粒子水平的 MoO ₂和N掺杂的碳多孔纳米八面体的协同作用，MoO ₂@NPC 电极表现出优异的电子/离子传输动力学、出色的结构完整性和令人印象深刻的钾离子存储性能，以及增强的循环稳定性和高倍率能力。密度泛函理论计算和实验测试证明MoO ₂ @NPC比MoO ₂和N掺杂的碳电极具有更高的钾亲和力和更高的电导率。动力学分析表明，MoO ₂ @NPC 纳米八面体的表面赝电容贡献大大增强。原位和非原位分析证实了 MoO ₂ @NPC 用于钾离子存储的插层反应机制。此外，组装的 MoO ₂@NPC//苝四甲酸二酐 (PTCDA) 全电池表现出良好的循环稳定性，在 200 次循环中在 100 mA g ^{-1 下}保持72.6 mAh g ^-1。因此，这里的这项工作不仅证明了一种有效且可行的结构工程策略，可以增强PIB中 MoO ₂材料的电化学行为，而且还全面了解钾离子与金属氧化物相互作用的动力学和机制。