Molybdenum phosphide (MoP), owing to its abundant reserve and high theoretical capacity, is regarded as a promising anode material for potassium-ion batteries. However, it still suffers from the problems of acute volume expansion and weak diffusion kinetics. This study reports a simple method to synthesize a composite of molybdenum phosphide and porous carbon (MoP@PC) through simple mixing and annealing treatment. In the MoP@PC, lots of MoP nanodots with an average diameter of about 4 nm uniformly embedded in the petal-like porous carbon. The MoP@PC shows reversible capacities of 330 mAh g⁻¹ at 100 mA g⁻¹ after 100 cycles, and ultra-long cycling stability with a capacity of 240 mAh g⁻¹ after 1000 cycles at 1 A g⁻¹ and 161 mAh g⁻¹ after 1000 cycles at 5 A g⁻¹. The structure of MoP@PC after charging-discharging cycles is also investigated by high resolution transmission electron microscope (HRTEM) and the result shows that MoP can still maintain the nanodot morphology without any agglomeration after 1000 cycles at 5 A g⁻¹. The storage mechanism of potassium ions was studied as well, which reveals that MoP and potassium ion have a conversion reaction.

磷钼（MoP）由于其丰富的储备和高的理论容量，被认为是钾离子电池的有希望的负极材料。然而，它仍然遭受急剧的体积膨胀和弱的扩散动力学的问题。这项研究报告了一种通过简单的混合和退火处理来合成磷化钼和多孔碳（MoP @ PC）的复合物的简单方法。在MoP @ PC中，许多平均直径约为4 nm的MoP纳米点均匀地嵌入花瓣状多孔碳中。MoP @ PC在100次循环后显示100 mA g ^-1时可逆容量为330 mAh g ^-1，在1 A g ^-1和161 mAh下经过1000次循环后可显示240 mAh g ^-1的超长循环稳定性G^-1在5 A g ^-1下循环1000次后。还通过高分辨率透射电子显微镜（HRTEM）研究了MoP @ PC的充放电循环后的结构，结果表明MoP在5 A g ^-1下循环1000次后仍能保持纳米点的形态，而不会发生团聚。还研究了钾离子的存储机理，表明MoP和钾离子具有转化反应。