DOI: 10.1002/aenm. 201500003 graphene, and macroporous graphene foams have been synthesized.[5, 18–20] Activated graphene with abundant ultrasmall micropores provides low volumetric capacitances and poor rate performance due to low ion-accessible surface area and tortuous ion diffusion channels. Mesoporous graphene and macroporous graphene foams can offer fast rate capability, which primarily results from fast flooding of the electrolyte in large empty spaces. However, these porous graphene foams with low packing density still exhibit low volumetric capacitances due to the shortage of micropores/mesopores. It is worth noting that the restacking of graphene nanosheets often inhibits the improvement of volumetric capacitance from their strong π–π interaction.[21–23] To prevent restacking, recently reported CNT/RGO microfiber electrodes with a packing density of 0.6 g cm− 3 have been innovatively prepared for fiber MSCs with a modest volumetric capacitance (300 F cm− 3).[24] However, low packing density and limited ion diffusion through graphene layers in fiber MSCs still undermine the effectiveness of further improving the volumetric capacitance and rate capability. In spite of such tremendous efforts, to resolve the trade-off, ie, to simultaneously achieve high volumetric energy density and high power density for MSCs, while retaining excellent cycling stability and short time constant, remains unanswered. Here, inspired by natural vein-textured leaves, we report a facile and scalable synthesis of nanochanneled and poly (diallyldimethylammonium chloride) PDDA-mediated RGO (nc-PDDA-Gr) film with high packing density and efficient 2D ion transport pathways. The vein-like-textured 2D nanochannels play a role of pathways for efficient ion diffusion parallel to the graphene planes. Interdigitated electrodes for MSCs fabricated by photolithography patterning of nanochanneled graphene facilitate ion diffusion in parallel to the film to maintain high rate capability regardless of the film thickness. High volumetric energy density of 6.7 mWh cm− 3 was obtained at a volumetric power density of 0.1 W cm− 3, with a slowly reduced energy density of 3.8 mWh cm− 3 at a high power density of 20 W cm− 3. It is the first time that such a high volumetric capacitance of 348 F cm− 3 or equivalently areal capacitance of 409 mF cm− 2 was obtained for a 11.8-µm-thick electrode. Combined with long cycling stability (50 000 cycles) and fast frequency response (33 ms), the 2D architectured graphene film intercalated by nanochanneled solid electrolyte can be a platform of MSCs for self-sustainable portable electronics and microelectromechanical systems with high volumetric energy density while retaining high power density. In a typical experiment, graphite oxide is easily obtained by strong oxidation of graphite. Interlayer distance is expanded to≈ 0.8 nm by the presence of functional groups in graphene plane.[25] Fully exfoliated graphene oxide (GO) with

Continuous miniaturization of portable electronics with enhancing functionality requires self-sustainable energy storage devices.[1, 2] One solution can be solid-electrolyte microbatteries, which are commercially available but suffer from sluggish rate capability and limited cycling stability. All-solidstate micro-supercapacitor (MSC) could be a promising alternative with high rate capability but simultaneously reaching high volumetric energy density remains challenging.[3–6] Typically, the electrode materials of MSCs require high electrical conductivity, high effective surface area, high ionic transport rate, and high electrochemical stability.[5, 7] The carbon-based porous materials are promising candidates to …