in LIBs are mostly organic and harmful, which inevitably enhance the difficulty and the cost of battery fabrication and also bring about some environmental impact. [3] As an alternative, rechargeable aqueous zinc-ion batteries (ZIBs) have shown great promise because of low toxicity, low cost, and the abundant distribution of zinc resources. [4] More importantly, zinc possesses a low redox potential (−0.762 V vs. standard hydrogen electrode) and a high theoretical capacity (819 mAh g −1 , 5851 mAh mL −1 ). [4d] Furthermore, zinc is stable in water, which can reduce the production cost and improve the safety. [5] Despite these advantages, it is a large challenge to develop a high-performance cathode material for aqueous ZIBs that provides high and stable capacities and keeps the structure integrity in Zn 2+ uptake, which is mainly due to heavy mass and high polarization of divalent Zn 2+ . Among various reported cathode materials (such as α, β, γ, and δ-MnO 2 , [4c,6] Prussian blue analogs, [7] Na 3 V 2 (PO 4 ) 3 , [8] and vanadium-based materials [9] ), vanadium pentoxide (V 2 O 5 ) is of particular interest owing to its high Zn 2+ ion storage capacity (≈590 mAh g −1 according to the two-electron redox center of vanadium) in its layered structure consisting of VO 5 units. [10] Unfortunately, V 2 O 5 cathodes exhibit rapid capacity decline during (de)intercalation of Zn 2+ due to the low ion diffusion coefficient, poor conductivity, elements dissolution, and selfaggregation. [11] To overcome this drawback, it has been reported that intercalation of H 2 O molecules into the interlayers of V 2 O 5 could effectively enlarge and maintain the layered configuration of V 2 O 5 -based materials, which offered high Zn 2+ ion storage capability and stable cycling performance. [5c,12] Also, by inserting other metallic ions such as Ca 2+ , [9a] Zn 2+ , [9e] Na + , [13] or Li + , [14] the formation of metal vanadium oxide bronzes has been demonstrated to enhance Zn 2+ storage performances. The typical structure of these metal vanadates is that the V-O layers expand along the c-axis while the intercalated metal ions and H 2 O molecules stay in the interlayer space. [15] Despite significant progress, further boosting the Zn 2+ storage ability of V 2 O 5 -based cathodes through other strategies is still urgently required, particularly at large rates.As a highly conductive and extremely stable polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) has been reported to not only effectively improve the electronic conductivity of Aqueous zinc-ion batteries (ZIBs) have become research focus because of their cost-effectiveness, high safety, and eco-friendliness. Unfortunately, sluggish Zn 2+ diffusion kinetics and the poor cycling stability in cathode materials impede their large-scale application. Herein, V 2 O 5 @poly(3,4ethylenedioxythiophene) (PEDOT) hybrid nanosheet arrays are uniformly deposited on carbon cloth (CC) as a superior ZIB cathode. The as-fabricated V 2 O 5 @PEDOT/CC electrode displays a maximum capacity of 360 mAh ...

storage device, lithium ion batteries can provide high energy but usually suffer from a low power rate and short life span. To overcome these drawbacks, researchers propose the so-called metal-ion capacitors, or hybrid batteries, which combine a battery anode and a capacitor electrode in order to achieve tradeoff between conventional battery and supercapacitor. [6][7][8] It is expected that such hybrid system delivers a capacitor-like fast charge/ discharge rate and battery-like high capacity. Since the first introduction in 2001, great progress has been achieved in the field of hybrid lithium-ion capacitors (LICs) through better understanding of the charge storage mechanism and the development of highperformance nanostructured materials. In a LIC, the capacitive cathode is typically a carbonaceous material that enables fast charge− discharge processes, while the reported battery-type anode includes Li 4 Ti 5 O 12 , [9,10] graphite, [11] TiO 2 , [12] MnO, [13] and LiVO 3 . [14] Sodium-ion batteries are becoming one of most promising battery technologies for the foreseeable grid-scale applications, because of more earth-abundant sodium source and their similar chemistry to that of the existing lithium-ion batteries. [15][16][17][18][19][20][21][22] Despite the potential low-cost, constructing hybrid sodium ion capacitors (NICs) faces more challenge because most Na host materials have a rather sluggish kinetic due to the large Na ion sizes. Research on NICs began in early 2012, [23] and was focused on improving the power capability of the anode in order to match the fast kinetics of the capacitive cathode. Strategies to increase sodium ion (Na + ) and electron (e − ) transport kinetics of NIC electrodes reported so far include: (1) developing new electrode materials (such as 2D MXene Ti 2 C, [24] V 2 C), [25] (2) constructing more conductive electrode structures by hybridizing with carbon (such as NaTi 2 (PO 4 ) 3 /rGO, [26] C@NVP, [27] Nb 2 O 5 @C/rGO, [28] TiO 2 mesocages@rGO, [29] and (3) shortening the ion diffusion and electron transport lengths by rational designing nanostructures (such as TiO 2 nanospheres, [30] Ti(O,N) nanowires, [31] Na 2 Ti 3 O 7 nanosheets [32] ). Despite these efforts, these reported anodes of NIC still have relatively limited rate performance and especially low Na-ion storage capacity. Among other reasons, most of these electrode materials are powder samples, which require substantial amount of conductive additives (such as super P, 10-20 wt%) and binder in order to make compact films. This not only weakens the electron transport but also unable to meet the flexibility requirement.Achieving high-performance Na-ion capacitors (NICs) has the particular challenge of matching both capacity and kinetics between the anode and cathode. Here a high-power NIC full device constructed from 2D metal-organic framework (MOFs) array is reported as the reactive template. The MOF array is converted to N-doped mesoporous carbon nanosheets (mp-CNSs), which are then uniformly encapsulated with VO 2 and Na...

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