AEM: 氟化2D-COFs膜@Zn电极提高离子传输

Fig.1 Design philosophy of TpBD-2F film: elucidating the synthesis process and the role of fluorinated nanochannels in guiding the rapid, uniform, and reversible Zn2+ plating/stripping process.

Fig.2 Property and structure characterization of TpBD-2F films. AFM images of a) TpBD@Zn, and b) TpBD-2F@Zn. c) FT-IR spectra of TpBD-2F and corresponding linkers. d) XPS F 1s spectra of TpBD and TpBD-2F. Semi-ionic C─F bond is found only in TpBD-2F. e) Measured XRD pattern, and simulated XRD patterns for AA and AB stacking of the TpBD-2F. f) Comparison of XRD pattern of experiment and Pawley-refined results. g) GI-XRD data of TpBD@Zn and TpBD-2F@Zn. h) Schematic illustration of the crystal growth orientation of TpBD-2F on a Zn substrate.

Fig.3 Investigation of ion transport behavior and de-solvation effect. a) EIS results of the symmetric cells in bare SS, TpBD@SS, or TpBD-2F@SS configurations. b) Calculated ion conductivity based on the EIS results. c) CA profiles of bare Zn, TpBD@Zn, and TpBD-2F@Zn symmetric cells. d) Schematic illustration of the diffusion behavior of Zn2+. e) Nyquist plots for TpBD-2F@Zn symmetric cell at different temperatures. f) Corresponding Arrhenius curves and comparison of activation energies of bare Zn, TpBD@Zn, and TpBD-2F@Zn. g) Electrostatic potential distributions of TpBD-2F. h) Schematic representation of 1D fluorinated nanochannels guiding ion transport and promoting de-solvation.

Fig.4 Characterization of HER and anti-corrosion properties. a) LSV curves using 1 m aqueous Na2SO4 electrolyte and corresponding Tafel slopes (inset). b) In situ pH monitoring of electrolytes with different anodes. SEM images of c,f) bare Zn, d,g) TpBD@Zn, and e,h) TpBD-2F@Zn after immersion in the electrolyte for 10 and 30 days, respectively. i) XRD patterns of TpBD-2F@Zn after different days of immersion. j) Linear polarization curves of bare Zn, TpBD@Zn, and TpBD-2F@Zn. Raman mapping of surface deposits on k) TpBD-2F@Zn, l) TpBD@Zn, and m) bare Zn after 160 h of plating/stripping (2 mAh cm−2, 2 mA cm−2).

Fig.5 Microscopic and mechanistic analysis of Zn deposits. In situ operando optical microscope images of Zn deposition behavior on a) bare Zn, b) TpBD@Zn, and c) TpBD-2F@Zn. SEM images of d,e) bare Zn and f,g) TpBD-2F@Zn anodes after high-rate cycling for 100 h in a homemade glass cell operating system. h) Schematic representation of Zn deposition behavior on TpBD-2F@Zn. Electric field simulation for i) bare Zn and l) TpBD-2F@Zn anodes. Corresponding Zn-ion flux distribution after a constant diffusion duration of 2 and 5 s of j,k) bare Zn and m,n) TpBD-2F@Zn anodes.

Fig.6 Electrochemical performance of asymmetric, symmetric, and full cells. a) Cyclic voltammograms and b) Coulombic efficiency of bare Ti//Zn, TpBD@Ti//Zn, and TpBD-2F@Ti//Zn asymmetric cells. Galvanostatic charge/discharge c) cycling performance, d) rate capability, and e) initial plating nucleation overpotential of bare Zn, TpBD@Zn, and TpBD-2F@Zn symmetric cells. f) Schematic diagram of energy storage principle of TpBD-2F@Zn//AC-based zinc ion capacitor. g) Long-term galvanostatic cycling performance of Zn//AC, TpBD@Zn//AC, and TpBD-2F@Zn//AC capacitors at 5 A g−1. h) Comparison of the lifespan of TpBD-2F@Zn anode with previously reported modified Zn anodes in Zn-ion capacitors under various current densities. i) Ex situ FT-IR spectra of TpBD-2F@Zn anodes at different voltages upon charge and discharge.

Ion-Transport Kinetics and Interface Stability Augmentation of Zinc Anodes Based on Fluorinated Covalent Organic Framework Thin Films

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