Mosaic Nanocrystalline Graphene Skin Empowers Pragmatic Zn Metal Anodes

Abstract

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.

Emerging strategies for steering orientational deposition toward high-performance Zn metal anodes

“…7(c)). 117 The adsorption configuration of water molecules on the NOC layer is illustrated in Fig. 7(d).…”

Synchronous Dual Electrolyte Additive Sustains Zn Metal Anode with 5600 h Lifespan

“…This might be ascribed to the retarded reaction kinetics with the XY dosage, despite the fact that it could modify the Zn 2+ solvation sheath [3] . Encouragingly, the introduction of GO would offset this drawback: the possible formation of ion transport channel via rGO would drastically decrease the polarization [31] . The nucleation overpotential at different current densities also shows the same trend (Figure S14).…”

“…Meanwhile, three fitted peaks centering at 531.0, 532.0 and 533.6 eV in the O 1s profile could be assigned to C=O, C−O/C−OH and O−C=O bonding, respectively (Figure 1g). [31] These abundant functional groups of rGO would play a vital role in the Zn electrodeposition. Electrochemical impedance spectroscopy (EIS) profiles of Zn−Zn symmetric cells using different electrolytes were further collected to derive the charge‐transfer resistance ( R ct , Figure 1h).…”

“…The Tafel profiles were further plotted to examine the corrosion behavior (Figure 3g). The cell with dual‐additives has the highest corrosion potential as well as lowest corrosion current density, representing a superior anti‐corrosion feature [31] . The inhibitory effect on parasitic side reactions in the presence of dual‐additives mainly originates from two aspects: the optimization of Zn 2+ solvation structure by XY and the isolation of water by rGO AIL.…”

“…Ultimately, there is no discernible by‐product signal in the case of ZS‐XY‐GO electrolyte. Note that the abundant oxygen‐containing groups (C=O and O−C=O) of rGO could interact with water molecules in the solvated shell, thus facilitating the desolvation process [31, 44] . In further contexts, temperature‐dependent EIS study was performed to probe the desolvation effect (Figure S20).…”