safety issues of organic electrolyte, and lithium dendrites. [3][4][5][6] Alternatively, rechargeable aqueous zinc-ion batteries (ZIBs) are increasingly attracting attention owing to their straightforward processing, high capacity of Zn metal anode (820 mAh g −1 ), [7] excellent safety, cost effectiveness (US$65 kWh −1 ), [8] higher ionic conductivity of aqueous electrolytes (≈1 S cm −1 ) than non-aqueous electrolytes (1-10 mS cm −1 ), [8] and two-electron transfer mechanism. [9] However, previous works of ZIBs based on the alkaline electrolytes still retain formidable challenges, such as inferior cyclability (≤1000 cycles), low coulombic efficiency (≤90%), and limited capacity (≤400 mAh g −1 at 0.1 A g −1 ), [1] mainly caused by the byproducts and unstable cathodes.To solve the above issues, much attention has been devoted to exploring highcapacity, electron-ion conductive, and structurally stable cathode materials, such as manganese oxides, [10][11][12] Prussian blue analogues (e.g., Zn 3 [Fe(CN) 6 ] 2 ), [13] NASICON-type materials (e.g., Na 3 V 2 (PO 4 ) 3 ), [14] transition metal sulfide (e.g., VS 2, Mo 6 S 2 ), [15,16] polymer (e.g., pyrene-4,5,9,10-tetraone, [17] polyaniline, [18] ), and vanadium-based compounds. [19][20][21] Recently, layered vanadium-based materials, including Zn 0.25 V 2 O 5 ·nH 2 O, [8] [9] and zinc orthovanadate, [24] have been recognized as a very promising class for high-safety aqueous ZIBs with respectable Zn-storage capacity of 300-400 mAh g −1 and cyclability (>1000 cycles), [25] originating from multivalence nature of vanadium cations and superior stability of layered structure. [22,26,27] It is noteworthy that all of the layered vanadium-based materials reported are composed of crystalline frameworks with doped metal ion or structural water, which neither sufficiently accommodates the structural strain during the (de)intercalation process nor provides ample active sites for efficient charge storage. [28,29] In a sharp contrast, amorphous frameworks can not only provide more exposed ion channels, accelerate rapid charge transfer across the electrode/electrolyte interface, and further facilitate fast ion intercalation, but also offer low internal energy and outstanding chemical stability. [30,31] Moreover, 2D heterostructures by alternating stacking of two type different 2D nanosheets produce Rechargeable aqueous zinc-ion batteries (ZIBs) are appealing due to their high safety, zinc abundance, and low cost. However, developing suitable cathode materials remains a great challenge. Herein, a novel 2D heterostructure of ultrathin amorphous vanadium pentoxide uniformly grown on graphene (A-V 2 O 5 /G) with a very short ion diffusion pathway, abundant active sites, high electrical conductivity, and exceptional structural stability, is demonstrated for highly reversible aqueous ZIBs (A-V 2 O 5 /G-ZIBs), coupling with unprecedented high capacity, rate capability, long-term cyclability, and excellent safety. As a result, 2D A-V 2 O 5 /G heterostructures for stacked ZIBs at 0.1 A g −1 dis...

The ability to pattern functional moieties with well-defined architectures is highly important in material science, nanotechnology and bioengineering. Although two-dimensional surfaces can serve as attractive platforms, direct patterning them in solution with regular arrays remains a major challenge. Here we develop a versatile route to pattern two-dimensional free-standing surfaces in a controlled manner assisted by monomicelle close-packing assembly of block copolymers, which is unambiguously revealed by direct visual observation. This strategy allows for bottom-up patterning of polypyrrole and polyaniline with adjustable mesopores on various functional free-standing surfaces, including two-dimensional graphene, molybdenum sulfide, titania nanosheets and even on one-dimensional carbon nanotubes. As exemplified by graphene oxide-based mesoporous polypyrrole nanosheets, the unique sandwich structure with adjustable pore sizes (5–20 nm) and thickness (35–45 nm) as well as enlarged specific surface area (85 m2 g−1) provides excellent specific capacitance and rate performance for supercapacitors. Therefore, this approach will shed light on developing solution-based soft patterning of given interfaces towards bespoke functions.

A cost-effective and industrially applicable screen printing protocol is demonstrated for scalable fabrication of graphene-based planar integrated micro-supercapacitors, with shape diversity, outstanding flexibility and superior modularization.

The rapid development and further modularization of miniaturized and self‐powered electronic systems have substantially stimulated the urgent demand for microscale electrochemical energy storage devices, e.g., microbatteries (MBs) and micro‐supercapacitors (MSCs). Recently, planar MBs and MSCs, composed of isolated thin‐film microelectrodes with extremely short ionic diffusion path and free of separator on a single substrate, have become particularly attractive because they can be directly integrated with microelectronic devices on the same side of one single substrate to act as a standalone microsized power source or complement miniaturized energy‐harvesting units. The development of and recent advances in planar MBs and MSCs from the fundamentals and design principle to the fabrication methods of 2D and 3D planar microdevices in both in‐plane and stacked geometries are highlighted. Additonally, a comprehensive analysis of the primary aspects that eventually affect the performance metrics of microscale energy storage devices, such as electrode materials, electrolyte, device architecture, and microfabrication techniques are presented. The technical challenges and prospective solutions for high‐energy‐density planar MBs and MSCs with multifunctionalities are proposed.

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