Potassium-ion batteries (KIBs) are new-concept of low-cost secondary batteries, but the sluggish kinetics and huge volume expansion during cycling, both rooted in the size of large K ions, lead to poor electrochemical behavior. Here, a bamboo-like MoS 2 /N-doped-C hollow tubes are presented with an expanded interlayer distance of 10 Å as a high-capacity and stable anode material for KIBs. The bamboo-like structure provides gaps along axial direction in addition to inner cylinder hollow space to mitigate the strains in both radial and vertical directions that ultimately leads to a high structural integrity for stable long-term cycling. Apart from being a constituent of the interstratified structure the N-doped-C layers weave a cage to hold the potassiation products (polysulfide and the Mo nanoparticles) together, thereby effectively hindering the continuing growth of solid electrolyte interphase in the interior of particles. The density functional theory calculations prove that the MoS 2 /N-doped-C atomic interface can provide an additional attraction toward potassium ion. As a result, it delivers a high capacity at a low current density (330 mAh g −1 at 50 mA g −1 after 50 cycles) and a high-capacity retention at a high current density (151 mAh g −1 at 500 mA g −1 after 1000 cycles).

Potassium-ion batteries are potential alternatives to lithium-ion batteries for large-scale energy storage considering the low cost and high abundance of potassium. However, it is challenging to obtain stable electrode materials capable of undergoing long-term potassiation/depotassiation due to the high accumulated stress associated with the huge volume variation of the electrode. Here, we simulate the von Mises stress distributions of four different carbon three-dimensional models under an isotropic initial stress by the finite element method and reveal the critical role of the structure of a hollow multihole bowl on the strain−relaxation behavior. In this regard, nitrogen/oxygen codoped carbon hollow multihole bowls (CHMBs) are synthesized via hydrothermal carbonization coupled with an emulsiontemplating strategy using biomass as the carbon source. Consistent with our simulation results, the CHMB anode remains stable for over 1000 cycles and delivers a high reversible capacity of 304 mAh g −1 at 0.1 A g −1 . In addition to the reduced stress accumulation, the good electrochemical performances are also attributed to the surface capacitive mechanism and the shortened electron/ion transport distance in CHMBs. In particular, the CHMB composite electrode has a volumetric specific capacity 56% higher than that of hollow spheres due to the high tapped density of the bowl-shaped particles.

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A mesoporous MoS2-monolayer/carbon composite was synthesized by a multirole organic-induced scalable method for superior lithium-ion and potassium-ion storage.