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The rationally structural engineering is an efficient strategy to improve the comprehensive performance of potassium‐ion storage anode materials. In this paper, a hybrid with hollow FeS2 nanoparticles anchored into the 3D carbon skeleton (labeled as H‐FeS2@3DCS) is successfully constructed through two critical steps of in situ chemical deposition and anion‐exchange reaction strategies. In the former, the water‐soluble Na2CO3 crystals are used as hard templates for the preparation of 3DCS, while Fe3+‐containing aqueous solutions are utilized to remove the Na2CO3 templates. Interestingly, the intense collision between Fe3+ and CO32‐ in aqueous solution produces nanoscale Fe(OH)3 colloidal particles, which are firmly anchored into the pores of the carbon skeleton to form a "lotus‐seed"‐like nanostructure. In the latter case, a central void space is created inside the FeS2 nanoparticles due to the different diffusion rates of S‐anions and Fe‐cations during the subsequent sulfidation process. Thanks to this unique composition model, the H‐FeS2@3DCS hybrid not only alleviates the volume expansion efficiently by rationally hollow structure design, but also provides spacious "roads" (3D carbon skeleton) and "houses" (hollow FeS2 nanoparticles) for fast K‐ion transition and storage. As the anode of PIBs and PIHCs, the resultant H‐FeS2@3DCS electrode delivers an obviously enhanced K‐ions storage performance over state‐of‐the‐art. [ABSTRACT FROM AUTHOR]

A NS-C@b-MoS 2 hybrid is readily fabricated with bilayer MoS 2 molecules grafted onto 3D N/S doped carbon capsule skeleton in one tailored spatial-chemical doubly confined mode. The MoS 2 bilayer can expose more S-Mo-S bonds to adsorb K-ions. Together with the support effect of carbon skeleton, consequently, this NS-C@b-MoS 2 hybrid electrode achieves an ultra-fast and ultra-stable potassium-ion storage capability. [Display omitted] • A tailored induced vapour-deposition strategy to construct a MoS 2 /C hybrid. • MoS 2 with bilayer structure can expose more S-Mo-S bonds to adsorb K-ions. • One spatial-chemical doubly confined mode to enhance the MoS 2 bilayer stability. • The assembled PIC deliver an ultra-stable performance up to 65,000 cycles. Few-layers MoS 2 -based materials have a comprehensive advantage in accommodating potassium-ions due to the rich active S-Mo-S sites and rapid ionic dynamics. Unfortunately, the serious self-stacking of MoS 2 molecular layer resulted in insufficient space to buffer the stress/strain caused by K-ions intercalation, which makes MoS 2 -based electrode exhibits low capacitance and poor cyclic stability in practical studies. To solve this, an in situ induced deposition strategy is proposed to construct a MoS 2 /C hybrid (labelled as NS-C@b-MoS 2). In this NS-C@b-MoS 2 hybrid, the MoS 2 molecular with bilayer structure is grafted onto a 3D N/S dual-doping carbon skeleton in one spatial-chemical doubly confined mode. This unique hybrid mode not only expose more S-Mo-S bonds to adsorb K-ions, but also avoid the structural collapse of electrode by spatial-chemical doubly confinement effect of carbon skeleton. Consequently, the resultant NS-C@b-MoS 2 anode delivers a high specific capacity of 451.2 mAh g−1 at 0.1 A g−1 and an ultra-long cycle stability up to 20,000 cycles with only 0.0013 % fading per cycle. Moreover, the assembled NS-C@b-MoS 2 //NSAC potassium-ion capacitor delivers a high energy density of 126.5 Wh kg−1 and retains 55.2 Wh kg−1 after 65,000 cycles at 3800 W kg−1, which over the state-of-the-art reported performance. [ABSTRACT FROM AUTHOR]