A new silicon oxycarbide based gas diffusion layer for zinc-air batteries

Prabu Moni; Amanda Deschamps; Daniel Schumacher; Kurosch Rezwan; Michaela Wilhelm

doi:10.1016/j.jcis.2020.05.041

A new silicon oxycarbide based gas diffusion layer for zinc-air batteries

J Colloid Interface Sci. 2020 Oct 1:577:494-502. doi: 10.1016/j.jcis.2020.05.041. Epub 2020 May 19.

Authors

Prabu Moni¹, Amanda Deschamps², Daniel Schumacher³, Kurosch Rezwan⁴, Michaela Wilhelm⁵

Affiliations

¹ University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, IW3, 28359 Bremen, Germany; CSIR-Central Electrochemical Research Institute-Madras Unit, CSIR Madras Complex, Taramani, Chennai 600 113, India.
² University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, IW3, 28359 Bremen, Germany; Department of Materials Engineering, Federal University of Santa Catarina (UFSC), 88040-900 Florianopolis, SC, Brazil.
³ University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, IW3, 28359 Bremen, Germany.
⁴ University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, IW3, 28359 Bremen, Germany; University of Bremen, MAPEX Center for Materials and Processes, Bibliothekstraße 1, 28359 Bremen, Germany.
⁵ University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, IW3, 28359 Bremen, Germany. Electronic address: mwilhelm@uni-bremen.de.

PMID: 32505008
DOI: 10.1016/j.jcis.2020.05.041

Abstract

Rational material designs play a vital role in the gas diffusion layer (GDL) by increasing the oxygen diffusion rate and, consequently, facilitating a longer cycle life for metal-air batteries. In this work, a new porous conductive ceramic membrane has been developed as a cathodic GDL for zinc-air battery (ZAB). The bilayered structure with a thickness of 390 μm and an open porosity of 55% is derived from a preceramic precursor with the help of the freeze tape casting technique. The hydrophobic behaviour of the GDL is proved by the water contact angle of 137.5° after the coating of polytetrafluoroethylene (PTFE). The electrical conductivity of 5.59 * 10^-3 S/cm is reached using graphite and MWCNT as filler materials. Tested in a ZAB system, the as-prepared GDL coated with commercial Pt-Ru/C catalyst shows an excellent cycle life over 200 cycles and complete discharge over 48 h by consuming oxygen from the atmosphere, which is comparable to commercial electrodes. The as-prepared electrode exhibits excellent ZAB performance due to the symmetric sponge-like structure, which facilitates the oxygen exchange rate and offers a short path for the oxygen ion/-electron kinetics. Thus, this work highlights the importance of a simple manufacturing process that significantly influences advanced ZAB enhancement.

Keywords: Freeze tape casting; Gas diffusion layer; Polymer-derived ceramics; Porous membrane; Zinc-air battery.