Zinc metal anode has garnered a great deal of scientific and technological interest. Nevertheless, major bottlenecks restricting its large‐scale utilization lie in the poor electrochemical stability and unsatisfactory cycling life. Herein, a Janus separator is developed via directly growing vertical graphene (VG) carpet on one side of commercial glass fiber separator throughout chemical vapor deposition. A simple air plasma treatment further renders the successful incorporation of oxygen and nitrogen heteroatoms on bare graphene. Thus‐derived 3D VG scaffold affording large surface area and porous structure can be viewed as a continuation of planar zinc anode. In turn, the Janus separator harvests homogenous electric field distribution and lowered local current density at the interface of the anode/electrolyte, as well as harnesses favorable zincophilic feature for building‐up uniform Zn ionic flux. Such a separator engineering enables an impressive rate and cycle performance (93% over 5000 cycles at 5 A g−1) for Zn‐ion hybrid capacitors and outstanding energy density (182 Wh kg−1) for V2O5//Zn batteries, respectively. This strategy with large scalability and cost‐effectiveness represents a universal route to protect prevailing metal anodes (Zn, Na, K) in rechargeable batteries.

Constructing a conductive carbon-based artificial interphase layer (AIL) to inhibit dendritic formation and side reaction plays a pivotal role in achieving longevous Zn anodes. Distinct from the previously reported carbonaceous overlayers with singular dopants and thick foreign coatings, a new type of N/O co-doped carbon skin with ultrathin feature (i.e., 20 nm thickness) is developed via the direct chemical vapor deposition growth over Zn foil. Throughout fine-tuning the growth conditions, mosaic nanocrystalline graphene can be obtained, which is proven crucial to enable the orientational deposition along Zn (002), thereby inducing a planar Zn texture. Moreover, the abundant heteroatoms help reduce the solvation energy and accelerate the reaction kinetics. As a result, dendrite growth, hydrogen evolution, and side reactions are concurrently mitigated. Symmetric cell harvests durable electrochemical cycling of 3040 h at 1.0 mA cm −2 /1.0 mAh cm −2 and 136 h at 30.0 mA cm −2 /30.0 mAh cm −2 . Assembled full battery further realizes elongated lifespans under stringent conditions of fast charging, bending operation, and low N/P ratio. This strategy opens up a new avenue for the in situ construction of conductive AIL toward pragmatic Zn anode.

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Constructing a conductive carbon-based artificial interphase layer (AIL) to inhibit dendritic formation and side reaction plays a pivotal role in achieving longevous Zn anodes. Distinct from the previously reported carbonaceous overlayers with sigular dopants and thick foreign coatings, a new type of N/O co-doped carbon skin with ultrathin feature (i.e., 20 nm thickness) is developed via the direct chemical vapor deposition growth over Zn foil. Throughout fine-tuning the growth conditions, mosaic nanocrystalline graphene could be obtained, which is proven crucial to enable the orientational deposition along Zn (002), thereby inducing a planar Zn texture. Moreover, the abundant heteroatoms help reduce the solvation energy and accelerate the reaction kinetics. As a result, dendrite growth, hydrogen evolution and side reactions are concurrently mitigated. Symmetric cell harvests durable electrochemical cycling of 3040 h at 1.0 mA cm− 2/1.0 mAh cm− 2 and 136 h at 30.0 mA cm− 2/30.0 mAh cm− 2. Assembled full battery further realizes elongated lifespans under stringent conditions of fast charging, bending operation and low N/P ratio. This strategy opens up a new avenue for the in-situ construction of conductive AIL toward pragmatic Zn anode.

Rechargeable Zn-ion battery has emerged as a promising alternative to Li-ion battery owing to the high safety and environmental benignity. Nevertheless, dendritic formation and side reaction occurred at the anode side greatly handicap its practical advance. Here, we put forward an effective maneuver to sustain practical Zn anode by optimizing the anode/electrolyte interface, which deals with the direct growth of an ultrathin nitrogen and oxygen co-doped carbon (NOC) overlayer over Zn foil via a scalable plasma enhanced chemical vapor deposition. Thus-designed NOC overlayer can guide the stable Zn deposition along Zn (002) because of the favorable adsorption by dopant atoms and cultivation effect of nanocrystalline carbons, thereby inducing a planar Zn texture. Moreover, the abundant heteroatoms help reduce the solvation energy and accelerate the reaction kinetics. As a result, dendrite growth and side reaction are concurrently mitigated. Symmetric cell harvests durable electrochemical cycling (1125 h at 10.0 mA cm− 2/1.0 mAh cm− 2; 136 h at 30.0 mA cm− 2/30.0 mAh cm− 2). Assembled full battery further realizes elongated lifespans under stringent conditions. This strategy marks a new avenue for the in-situ construction of ultrathin protective coating to optimize the Zn deposition electrochemistry toward pragmatic Zn anode.