Edge-enriched MoS₂ for kinetics-enhanced potassium storage

Potassium-ion batteries (PIBs) hold great promise as alternatives to lithium ion batteries in post-lithium age, while face challenges of slow reaction kinetics induced by the inherent characteristics of large-size K⁺. We herein show that creating sufficient exposed edges in MoS₂ via constructing ordered mesoporous architecture greatly favors for improved kinetics as well as increased reactive sites for K storage. The engineered MoS₂ with edge-enriched planes (EE-MoS₂) is featured by three-dimensional bicontinuous frameworks with ordered mesopores of ~ 5.0 nm surrounded by thin wall of ~ 9.0 nm. Importantly, EE-MoS₂ permits exposure of enormous edge planes at pore walls, renders its intrinsic layer spacing more accessible for K⁺ and accelerates conversion kinetics, thus realizing enhanced capacity and high rate capability. Impressively, EE-MoS₂ displays a high reversible charge capacity of 506 mAh·g^-1 at 0.05 A·g^-1, superior cycling capacities of 321 mAh·g^-1 at 1.0 A·g^-1 after 200 cycles and a capacity of 250 mAh·g^-1 at 2.0 A·g^-1, outperforming edge-deficient MoS₂ with nonporous bulk structure. This work enlightens the nanoarchitecture design with abundant edges for improving electrochemical properties and provides a paradigm for exploring high-performance PIBs.