Layer‐structured metal vanadates have attracted extensive attention as cathode materials due to multi‐electron redox reactions and versatile cations storage capability. Nevertheless, their actual promotion is still hindered by the sluggish reaction kinetics and inferior phase transition upon repeated cations (de)intercalation. Here, large‐sized NH4+ is introduced into the K‐site of K0.43(NH4)0.12V2O5–δ to enable more kinetically favorable oxygen vacancies. The reinforced structure ensures complete solid‐solution phase transition and buffers the dramatic structural change upon potassium storage. The stable presence of NH4+ as pillars during cycling is also confirmed. Meanwhile, the oxygen vacancies induced by alkali‐site substitution can facilitate ion diffusion and enhance the electronic conductivity, as further demonstrated by theoretical calculations. Therefore, it exhibits a high capacity of 117.8 mA g−1 at 20 mA g−1 with smooth profiles and superior capacity retention of 92.5% after 800 cycles at 1000 mA g−1. Such an effective synergetic strategy also promotes its zinc storage capability, which performs negligible self‐discharge behavior and retains a reversible capacity of 216.8 mAh g−1 after 3000 cycles at 10 A g−1. This synergetic strategy may provide novel perspectives to develop layer‐structured cathode and facilitate its practical application in energy storage devices.

β-FeOOH is employed as an anode for potassium-ion batteries, exhibiting high capacity and good cycling stability. The K+ storage mechanism of β-FeOOH is being investigated.

Carbonaceous anodes of potassium-ion batteries (PIBs) hold sluggish adsorption and diffusion kinetics due to the large radius of K+, leading to poor cyclic stability and low specific capacity. Herein, an amorphous carbon material composed of N/P-doped active sites and trace amount of metallic zinc (Zn-NPC) is prepared through a facile self-sacrificing template method. Both experimental data and theoretical calculations indicate the co-doping of metallic zinc, and N/P atoms contribute to the low charge transfer impedance, high electronic conductivity, significant adsorption behavior, and remarkable diffusion kinetics of K+ ions. As a result, Zn-NPC anode delivers high capacity of 300.1 mA h g−1 at 50 mA g−1, and superior cycle performance with a reversible capacity of 196.1 mA h g−1 after 1400 cycles at 200 mA g−1. This work will open window for the doping strategy of carbon material and facilitate the practical application of PIBs in the energy storage field.