Dual 3D Ceramic Textile Electrodes: Fast Kinetics for Carbon Oxidation Reaction and Oxygen Reduction Reaction in Direct Carbon Fuel Cells at Reduced Temperatures

Abstract

Abstract Direct carbon fuel cells (DCFCs) are an efficient energy‐conversion technology capable of generating electricity with carbon‐dioxide‐capture chemistry with solid carbon as fuels. The efficiency and performance of DCFCs depend on the kinetics of the carbon oxidation reactions (COR) and the oxygen reduction reactions (ORR), each occurring at anode and cathode, respectively. The limited active sites paired with reduced temperatures greatly decrease the efficiency of the electrochemical reactions. Ultraporous dual‐3D ceramic textiles (dual‐3DCT) are integrated into electrolyte‐supported DCFCs to enhance charge and mass transfer at the electrodes. Improved COR at the anode is achieved by the synergy between the 3DCT NiO–Ce 0.8 Gd 0.2 O 1.95 (GDC) structure and optimal carbon fuel choice. In a comparative study, DCFCs using graphitic carbon (GC) as fuel show the best COR performance when compared to DCFCs utilizing alternative fuels such as carbon black (CB) and activated carbon (AC). The 3DCT Sm 0.5 Sr 0.5 CoO 3‐δ –GDC (SSC–GDC) composite cathode shows electrochemical performance superior to that of the conventional screen‐printed SSC–GDC. A peak power density of 392 mW cm −2 at 600 °C is obtained in a DCFC using the 3DCT‐anode/electrolyte/3DCT‐cathode configuration, an unprecedented value for any reported DCFC as of yet. This points toward promising applications of dual‐3DCT electrodes for reduced‐temperature DCFCs.

Key findings

• ▸Dual 3D ceramic textiles enhanced charge and mass transfer at the electrodes, improving carbon oxidation reaction efficiency.
• ▸The use of graphitic carbon as fuel resulted in the best carbon oxidation reaction performance compared to carbon black and activated carbon.
• ▸The synergy between the 3DCT NiO–Ce0.8Gd0.2O1.95 structure and optimal carbon fuel choice improved carbon oxidation reaction efficiency.

Keywords

Identifiers

DOI

10.1002/adfm.201910096

Journal

Advanced Functional Materials

Year

2020