Potassium-ion batteries (KIBs) are among the most promising alternatives to lithium-ion batteries (LIBs), but suffer from substantial challenges for success due to difficulties in constructing suitable electrode materials that can robustly host the large ionic radius of K⁺ ions. Herein, a desired CoP/carbon composite with ultrasmall CoP nanoparticles confined into nitrogen-doped porous carbon (CoP@NPC) is facilely constructed by a synchronous pyrolysis and phosphorization strategy. Relying on the structural merits that can offer highly electrical conductivity, reduced and effective transport pathways, abundant active sites and robust structural stability, the composite can achieve efficient K-storage including relatively higher reversible capacity, better rate capability and enhanced long cycling stability. In addition, K⁺ ions diffusion kinetics and electrochemical storage mechanism are elucidated. The present work is expected to provide a new venue for the facile design and construction of advanced transition-metal phosphides (TMPs)-based electrode materials for rechargeable KIBs.

钾离子电池（KIB）是锂离子电池（LIB）的最有希望的替代品之一，但由于难以构建能够牢固地容纳K ⁺较大离子半径的合适电极材料，因此成功面临巨大挑战。离子。在此，通过同步热解和磷化策略容易地构建具有限制在氮掺杂的多孔碳中的超小CoP纳米颗粒的所需CoP /碳复合物（CoP @ NPC）。依靠可提供高电导率，减少和有效的运输途径，丰富的活性位点以及强大的结构稳定性的结构优点，复合材料可实现有效的K储存，包括相对较高的可逆容量，更好的倍率容量和增强的长循环稳定性。另外，K ⁺阐明了离子扩散动力学和电化学存储机理。预计目前的工作将为可充电KIB的高级过渡金属磷化物（TMP）基电极材料的便捷设计和构造提供一个新的场所。