The main challenge for sodium/potassium ion storage is to find the suitable host materials to accommodate the larger-sized Na⁺/K⁺ and conquer the sluggish chemical kinetics. Herein, by selenation of polyoxometalate in electrospinning fiber, a novel MoO₂/MoSe₂ heterostructure embedded in one-dimensional (1D) N,P-doped carbon nanofiber (MoO₂/MoSe₂@NPC) is rationally constructed to show distinct enhancement of rate performance and cycle life for sodium ion batteries (SIBs) and potassium ion batteries (PIBs). The 1D skeleton of MoO₂/MoSe₂@NPC decreases the diffusion pathway of Na⁺/K⁺, and the doping of N/P heteroatoms in carbon fiber creates abundant active sites and provides good reachability for Na⁺/K⁺ transportation. MoSe₂ nanosheets grow in the bulk phase of MoO₂via in situ local phase transformation to achieve effective and firm heterointerfaces. Especially, the exposure extent of heterointerfaces can be controlled by treatment temperature during the preparation process, and the optimized heterointerfaces result in an ideal synergic effect between MoO₂ and MoSe₂. DFT calculations confirm that the internal electric field in the heterogeneous interface guides the electron transfer from MoO₂ to MoSe₂, combined with strong adsorption capacity toward sodium/potassium, facilitating ion/electron transfer kinetics. It is confirmed that the MoO₂/MoSe₂@NPC anode for SIBs delivers 382 mA h g^–1 under 0.1 A g^–1 upon 200 cycles; meanwhile, a reversible capacity of 266 mA h g^–1 is maintained even under 2 A g^–1 after 2000 cycles. For PIBs, it can reach up to 216 mA h g^–1 in the 200th cycle and still retain 125 mA h g^–1 after 2000 cycles under 1 A g^–1. This study opens up a new interface manipulation strategy for the design of anode materials to boost fast Na⁺/K⁺ storage kinetics.

中文翻译：

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操纵 MoO2/MoSe2 异质界面提高钠/钾存储的高速率和耐用性

钠/钾离子存储的主要挑战是找到合适的主体材料来容纳更大尺寸的 Na ⁺ /K ⁺并克服缓慢的化学动力学。在此，通过在静电纺丝纤维中硒化多金属氧酸盐，合理地构建了嵌入一维（1D）N，P掺杂碳纳米纤维（MoO ₂ /MoSe ₂ @NPC）中的新型MoO ₂ /MoSe ₂异质结构，以显示出明显的增强钠离子电池 (SIB) 和钾离子电池 (PIB) 的倍率性能和循环寿命。_{MoO 2} /MoSe ₂ @NPC的一维骨架减少了Na ⁺ /K ⁺的扩散途径，并且碳纤维中N/P杂原子的掺杂创造了丰富的活性位点，并为Na ⁺ /K ⁺传输提供了良好的可达性。MoSe _2纳米片通过原位局部相变在MoO ₂的体相中生长，以实现有效且牢固的异质界面。特别是异质界面的暴露程度可以通过制备过程中的处理温度来控制，优化后的异质界面使MoO ₂和MoSe ₂之间的协同效应达到理想。DFT计算证实异质界面中的内部电场引导电子从MoO ₂转移到MoSe ₂，结合对钠/钾的强大吸附能力，促进离子/电子转移动力学。经证实，用于 SIB 的 MoO ₂ /MoSe ₂ @NPC 阳极在 0.1 A g ^-1下在 200 次循环下可提供 382 mA hg ^-1电流；同时，在 2000 次循环后，即使低于 2 A g ^{-1也能保持 266 mA hg -1}的可逆容量。对于 PIB，它可以在第 200 个循环中达到高达 216 mA hg ^–1 ，并且在 1 A g –1 下 2000 个循环后^仍保持 125 mA hg ^–1。该研究为阳极材料的设计开辟了一种新的界面操纵策略，以提高快速 Na ⁺ /K ⁺储存动力学。