Zn-based aqueous batteries have attracted much attention because of their high theoreticalcapacity, safety, and low-cost, yet the H 2 -evolution, qualification or inhibition mechanism investigations that are closely related to the dendrite-growth are rare and challenging. Herein, a series of zincophilic metal-covalent organic frameworks (e.g., Zn-AAn-COF, Zn-DAAQ-COF, and Zn-DAA-COF) have been explored as model-platforms to manipulate the H 2 -evolution and Zn 2 + flux. Best of them, Zn-AAn-COF based cell only produces 0.002 mmol h À 1 cm À 2 H 2 , which is > 2 orders of magnitude lower than bare Zn. Noteworthy, it affords high stability for 3000 cycles (overpotential, < 79.1 mV) at 20 mA cm À 2 in symmetric-cell and enhanced cyclingstability up to 6000 cycles at 2000 mA g À 1 in the assembled full-battery. Besides, mechanistic characterizations show that Zn-AAn-COF can enhance the energy-barrier of H 2 -evolution and homogenize the iondistribution or electric-filed to achieve high performance.
The inhomogeneous consumption of anions and direct contact between electrolyte and anode during the Zn-deposition process generate Zn-dendrites and side reactions that can aggravate the space-charge effect to hinder the practical implementation of zinc-metal batteries (ZMBs). Herein, electrospray has been applied for the scalable fabrication (> 10 000 cm 2 in a batchexperiment) of hetero-metallic cluster covalent-organicframeworks (MCOF-Ti 6 Cu 3 ) nanosheet-coating (MNC) with integrated micro space electrostatic field for ZMBs anode protection. The MNC@Zn symmetric cell presents ultralow overpotential ( � 72.8 mV) over 10 000 cycles at 1 mAh cm À 2 with 20 mA cm À 2 , which is superior to bare Zn and state-of-the-art porous crystalline materials. Theoretical calculations reveal that MNC with integrated micro space electrostatic field can facilitate the deposition-kinetic and homogenize the electric field of anode to significantly promote the lifespan of ZMBs.
The elaborate design of powerful Li–S binders with extended‐functions like polysulfides adsorption/catalysis and Li+ hopping/transferring in addition to robust adhesion‐property has remained a challenge. Here, an in situ cathode‐interweaving strategy based on metalloporphyrin based covalent‐bonding organic polymer (M‐COP, M = Mn, Ni, and Zn) binders is reported for the first time. Thus‐produced functional binders possess excellent mechanical‐strengths, polysulfides adsorption/catalysis, and Li+ hopping/transferring ability. Specifically, the modulus of Mn‐COP can reach up to ≈54.60 GPa (≈40 times higher than poly(vinylidene fluoride)) and the relative cell delivers a high initial‐capacity (1027 mAh g‐1, 1 C and 913 mAh g‐1, 2 C), and excellent cycling‐stability for >1000 cycles even at 4 C. The utilization‐rate of sulfur can reach up to 81.8% and the electrodes based on these powerful binders can be easily scale‐up fabricated (≈20 cm in a batch‐experiment). Noteworthy, Mn‐COP based cell delivers excellent capacities at a high sulfur‐loading (8.6 mg cm‐2) and low E/S ratio (5.8 µL mg‐1). In addition, theoretical calculations reveal the vital roles of metalloporphyrin and thiourea‐groups in enhancing the battery‐performance.
Zn-based aqueous batteries have attracted much attention because of their high theoreticalcapacity, safety, and low-cost, yet the H 2 -evolution, qualification or inhibition mechanism investigations that are closely related to the dendrite-growth are rare and challenging. Herein, a series of zincophilic metal-covalent organic frameworks (e.g., Zn-AAn-COF, Zn-DAAQ-COF, and Zn-DAA-COF) have been explored as model-platforms to manipulate the H 2 -evolution and Zn 2 + flux. Best of them, Zn-AAn-COF based cell only produces 0.002 mmol h À 1 cm À 2 H 2 , which is > 2 orders of magnitude lower than bare Zn. Noteworthy, it affords high stability for 3000 cycles (overpotential, < 79.1 mV) at 20 mA cm À 2 in symmetric-cell and enhanced cyclingstability up to 6000 cycles at 2000 mA g À 1 in the assembled full-battery. Besides, mechanistic characterizations show that Zn-AAn-COF can enhance the energy-barrier of H 2 -evolution and homogenize the iondistribution or electric-filed to achieve high performance.
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