to exceptional mechanical flexibility within the layer and remarkable rigidity perpendicular to the layers. This anisotropic structural feature also conduces to effective chemical complexing. And attributed to the weak interlayer interactions, layer structured materials can readily be expanded, exfoliated, or self-assemble into various nanoarchitectures and the processes are always accompanied by the introduction of defects or phase transformation. [3] Therefore, layer structured materials show some unique application performances that nonlayer structured ones are hard to achieve. Specifically, the abilities of fast ion intercalation and charge transfer enable unparalleled high initial Coulombic efficiency, unexpected structure reversibility, and the formation of extra chemical bonds with other materials when used in alkali-metal ion batteries including lithium ion batteries (LIBs), sodium ion batteries (NIBs), and potassium ion batteries (KIBs). [4] The exfoliative feature induced high specific surface area, large amount of active sites as well as effective defect/strain/phase engineering also promise the feasibility to develop outstanding capacitor materials and efficient catalysts. Moreover, the superior mechanical flexibility and impressive energy storage capacity of layer structured materials could satisfy the requirement of the flexible devices. It is also feasible to develop new battery systems such as the aluminum or magnesium rechargeable batteries using the interlayer expansion approach. [5] With these unique properties, layer structured materials are expected to play more important roles in energy storage and conversion devices.However, the current available reviews involving layer structured materials are mostly based on their derivative 2D nanomaterials and the correlations between layer number and the final performances, [6] or focused much on synthetic methods, [3] advanced characterizations, [7] or centered on specific materials such as MoS 2 , [8] graphene, [9] transitional metal dichalcogenides (TMDs), [10] etc. In this review, great importance is attached to structural characteristics of layered materials and their unique performances induced by the inherent structural features when applied in energy storage and conversion. We start with a brief introduction of typical layered materials and their crystal structures, and then we summarize their structure endued exceptional properties. Afterwards, we highlight the layered structure Owing to the strong in-plane chemical bonds and weak van der Waals force between adjacent layers, investigations of layer structured materials have long been the hotspots in energy-related fields. The intrinsic large interlayer space endows them capabilities of guest ion intercalation, fast ion diffusion, and swift charge transfer along the channels. Meanwhile, the well-maintained in-plane integrity contributes to exceptional mechanical properties. This anisotropic structural feature is also conducive to effective chemical combination, exfoliation, or self-assembly in...