Rechargeable sodium/potassium‐ion batteries (SIBs/PIBs) with abundant reserves of Na/K and low cost have been a promising substitution to commercial lithium‐ion batteries. As for pivotal anode materials, metal sulfides (MSx) exhibit an inspiring potential due to the multitudinous redox storage mechanisms for SIBs/PIBs applications. Nevertheless, they still confront several bottlenecks, such as the low electrical conductivity, poor ionic diffusivity, sluggish interfacial/surface reaction kinetics, and severe volume expansion, which distinctly restrain the battery performance. Meanwhile, the systematic insights into the design strategies of MSx for SIBs/PIBs have been seldom elaborated. In this review, the energy storage mechanism, challenge, and design strategies of MSx for SIBs/PIBs are expounded to address the above predicaments. In particular, design strategies of MSx are highlighted from the aspects of morphology modifications involving 1D/2D/3D configurations, atomic‐level engineering containing heteroatom doping, vacancy creation, and interlayer spacing expansion, and MSx composites with other MSx, metal oxides, carbonaceous, and graphite materials to boost the comprehensive electrochemical performance of SIBs/PIBs. Furthermore, prospects are presented for the further advance of MSx to surmount imminent challenges, hoping to forecast feasible future orientations in this field.

Heterostructure construction of layered metal chalcogenides can boost their alkali‐metal storage performance, where the charge transfer kinetics can be promoted by the built‐in electric fields. However, these heterostructures usually undergo interface separation due to severe layer expansion, especially for large‐size potassium accommodation, resulting in the deconstruction of heterostructures and battery performance fading. Herein, first a stable interface design strategy where two metal chalcogenides with totally different layer‐morphologies are stacked to form large K+ transport channels, rendering ultralow interlayer expansion, is presented. As a proof of concept, the flat–zigzag MoS2/Bi2S3 heterostructures stacked with zigzag‐morphology Bi2S3 and flat‐morphology MoS2 present an ultralow expansion ratio (1.98%) versus MoS2 (9.66%) and Bi2S3 (9.61%), which deliver an ultrahigh potassium storage capacity of above 600 mAh g−1 and capacity retention of 76% after 500 cycles, together with the built‐in electric field of heterostructures. Once the heterostructures are used as an anode for potassium‐based dual‐ion batteries (K‐DIBs), it achieves a superior full‐cell capacity of ≈166 mAh g−1 with a capacity retention of 71% after 400 cycles, which is an outstanding performance among the reported K‐DIBs. This proposed interface stacking strategy may offer a new way toward stable heterostructure design for metal ions storage and transport applications.