Development of lanthanum strontium cobalt ferrite perovskite electrodes of solid oxide fuel cells – A review

Supercapacitors are increasingly used for energy conversion and storage systems in sustainable nanotechnologies. Graphite is a conventional electrode utilized in Li-ion-based batteries, yet its specific capacitance of 372 mA h g−1 is not adequate for supercapacitor applications. Interest in supercapacitors is due to their high-energy capacity, storage for a shorter period and longer lifetime. This review compares the following materials used to fabricate supercapacitors: spinel ferrites, e.g., MFe2O4, MMoO4 and MCo2O4 where M denotes a transition metal ion; perovskite oxides; transition metals sulfides; carbon materials; and conducting polymers. The application window of perovskite can be controlled by cations in sublattice sites. Cations increase the specific capacitance because cations possess large orbital valence electrons which grow the oxygen vacancies. Electrodes made of transition metal sulfides, e.g., ZnCo2S4, display a high specific capacitance of 1269 F g−1, which is four times higher than those of transition metals oxides, e.g., Zn–Co ferrite, of 296 F g−1. This is explained by the low charge-transfer resistance and the high ion diffusion rate of transition metals sulfides. Composites made of magnetic oxides or transition metal sulfides with conducting polymers or carbon materials have the highest capacitance activity and cyclic stability. This is attributed to oxygen and sulfur active sites which foster electrolyte penetration during cycling, and, in turn, create new active sites.

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Advanced materials and technologies for supercapacitors used in energy conversion and storage: a review

The development of transition-metal-oxides (TMOs)-based bifunctional catalysts toward efficient overall water splitting through delicate control of composition and structure is a challenging task. Herein, the rational design and controllable fabrication of unique heterostructured inter-doped ruthenium-cobalt oxide [(Ru-Co)Ox ] hollow nanosheet arrays on carbon cloth is reported. Benefiting from the desirable compositional and structural advantages of more exposed active sites, optimized electronic structure, and interfacial synergy effect, the (Ru-Co)Ox nanoarrays exhibited outstanding performance as a bifunctional catalyst. Particularly, the catalyst showed a remarkable hydrogen evolution reaction (HER) activity with an overpotential of 44.1 mV at 10 mA cm-2 and a small Tafel slope of 23.5 mV dec-1 , as well as an excellent oxygen evolution reaction (OER) activity with an overpotential of 171.2 mV at 10 mA cm-2 . As a result, a very low cell voltage of 1.488 V was needed at 10 mA cm-2 for alkaline overall water splitting.

Heterostructured Inter-Doped Ruthenium-Cobalt Oxide Hollow Nanosheet Arrays for Highly Efficient Overall Water Splitting.

Synthesis, characterizations, and utilization of oxygen-deficient metal oxides for lithium/sodium-ion batteries and supercapacitors

Recent advances in perovskite oxides for anion-intercalation supercapacitor: A review

Transition metal phosphating Pd@NiP nanoparticles supported by reduced graphene oxide were successfully synthesized by a one-step in situ synthesis method. The Pd@NiP/rGO nanoparticles were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), confocal Raman spectroscopy (Raman), Fourier transform infrared spectroscopy (FT-IR), and BET. Compared with Pd/rGO and Pd@Ni/rGO, Pd1@Ni12.5P40/rGO exhibited stronger catalytic activity, with TOF value reaching 133.33 min-1 and activation energy (Ea) of 29.31 kJ mol-1. This excellent catalytic performance may be related to the good dispersion of nanoparticles and the synergistic electron interactions between transition metal phosphating compounds.

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Yihui Liu

Papers

Highly Efficient Dehydrogenation of Ammonia Borane over Reduced Graphene Oxide-Supported Pd@NiP Nanoparticles at Room Temperature

Mo doped Ruddlesden-Popper Pr1.2Sr0.8NiO4+δ oxide as a novel cathode for solid oxide fuel cells