Abstract
Renewable potassium-ion energy storage shows attractive potential due to high-discharge platform and sufficient energy density, with outstanding advantages of abundant reserves and cost-effectiveness. However, key anode materials face various bottlenecks and formidable challenges, such as poor electrical conductivity, low ionic diffusivity, sluggish interfacial/surface reaction, and severe volume expansion, which distinctly inhibit the electrochemical performance of potassium-ion system. The construction of heterostructures can synergistically improve the deficiencies and combine the unique functionalities of different materials to enhance the potassium-ion storage capacity of metal chalcogenides or oxides. In this review, understandings and insights into the diffusion and kinetic behavior of mixed-dimensional heterostructures (MDHs) will be systematically discussed and revealed. Furthermore, these benefits and merits will be maximized and optimized, accompanied by recent state-of-the-art synthetic strategies and characterization techniques. Finally, we propose improvements and perspectives for the feasible development of heterostructures in next-generation energy storage systems.