High-Temperature Current Collection Enabled by the in Situ Phase Transformation of Cobalt–Nickel Foam for Solid Oxide Fuel Cells

Abstract

For the commercial development of solid oxide fuel cells (SOFCs), cathode current collection has been one of the most challenging issues because it is extremely difficult to form continuous electric paths between two rigid components in a high-temperature oxidizing atmosphere. Herein, we present a Co-Ni foam as an innovative cathode current collector that fulfills all strict thermochemical and thermomechanical requirements for use in SOFCs. The Co-Ni foam is originally in the form of a metal alloy, offering excellent mechanical properties and manufacturing tolerance during stack assembly and startup processes. Then, it is converted to the conductive spinel oxide in situ during operation and provides nearly ideal structural and chemical characteristics as a current collector, gas distributor, and load-bearing component. The functionality and durability of the Co-Ni foam are verified by unit cell test and 1 kW-class stack operation, demonstrating performance that is equivalent to that of precious metals as well as an exceptional stability under dynamic conditions with severe temperature and current variations. This work highlights a cost-effective technique to achieve highly reliable electric contacts over the large area using the in situ metal-to-ceramic phase transformation that could be applied to various high-temperature electrochemical devices.

Hydrazine Hydrate Induced Three-Dimensional Interconnected Porous Flower-like 3D-NiCo-SDBS-LDH Microspheres for High-Performance Supercapacitor

“…For example, NiCo-LDH had superior high theoretical specific capacitance of 774 F•g −1 at the current density of 0.2 A•g −1 [10]. However, the relatively sluggish electrochemical reaction kinetics of NiCo-LDH, like the relatively low charge transport rate, the low specific surface area, poor conductivity, and limited exposed electroactive sites, consequently, hinders the electrochemical performance [11][12][13].…”

Interface Fracture Energy of Contact Layers in a Solid Oxide Cell Stack

“…Recently, the use of metallic CuMn or CuNi alloy foam as a new type of contact layer was suggested [25][26][27]. The flexibility of these foams in the metallic state allows for greater manufacturing tolerances, while the highly porous structure is ideal for gas permeation.…”

“…Recently, the use of metallic CuMn or CuNi alloy foam as a new type of contact layer was suggested. − The flexibility of these foams in the metallic state allows for greater manufacturing tolerances, while the highly porous structure is ideal for gas permeation. During heat-up of the stack, the metallic foams are converted to conductive spinel oxides such as Cu 1+ x Mn 2– x O 4 (∼200 S/cm 2 at 750 °C) in the case of the CuMn foam …”

Nanowire‐Intensified Metal‐Enhanced Fluorescence in Hybrid Polymer‐Plasmonic Electrospun Filaments

“…In this respect, metal particles embedded within the core of active waveguides would lead to much more stable and optically robust systems. Various methods are currently available for the production of functional elongated nanostructures and active dielectric filaments embedding NPs, including electrospinning which allows continuous and multifunctional composite nanofibers to be obtained. Single photons and ensemble emission coupling to modes of electrospun nanofibers have been reported, as well as fluorescent filaments used as active components in lasers, fluorescent barcodes, and UV excitation sources .…”