Flexible Three-Dimensional Hierarchical Porous Multifunctional Electrodes for Enhanced Performance by Electrodepositing Perovskite CeFeO₃ on Carbon Foam

Abstract

Rechargeable lithium-oxygen cells are promising because of their high theoretical energy density, but they still face some challenges for applications. To address the problems like large polarization and poor reversibility of oxygen electrodes, a reversible binder-free three-dimensional (3D) hierarchical porous cathode was constructed by electrodepositing perovskite cerium orthoferrite CeFeO 3 nanoparticles on flexible graphite foam (GF) via a facile way. It exhibits a low overpotential for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) and delivers a high initial discharge capacity of 11.53 mAh•cm −2 at 0.04 mA• cm −2 , about 10 times that of pristine GF. The charge transfer resistance of GF is reduced by about 81% by CeFeO 3 , while the ORR and OER peak current densities are increased by 982 and 1167%, respectively. Furthermore, CeFeO 3 can efficiently suppress the side reactions of GF to reduce the overpotential and improve the cycle performance during cycles. Multifarious results reveal that the superior catalytic activities of CeFeO 3 and hierarchical porous structure are responsible for the excellent electrochemical performance. It paves a novel way to develop a multifunctional electrocatalyst for oxygen electrodes by combining catalysis and microstructure using a green electrochemical method.

Hollow Carbon Cages Derived from Polyoxometalate‐Encapsuled Metal‐Organic Frameworks for Energy‐Saving Hydrogen Production

“…As shown in Figure S18 and Table S2, the EIS spectra shows that all the samples exhibited similar solution resistances (R S ) ranging from 3.442 to 4.838 Ω in all three electrolytes. Remarkably, the PW‐NiCo‐NC displays much smaller charge transfer resistances (R CT ) than PW‐Co‐NC and similar to Co‐NC in all three electrolytes, indicating that the Ni 3 N nanoparticles not only act as active sites, but also facilitate the electron transfer [86] …”

“…Remarkably, the PW-NiCo-NC displays much smaller charge transfer resistances (R CT ) than PW-Co-NC and similar to Co-NC in all three electrolytes, indicating that the Ni 3 N nanoparticles not only act as active sites, but also facilitate the electron transfer. [86] The HER performances of the as-prepared samples were also evaluated in the three-electrode system using 1 M KOH as electrolyte (Figure S19). The commercial Pt/C was taken as the reference.…”