Root cause analysis of the degradation in a unitized regenerative fuel cell

Abstract

______________________________________________________________________________ The present study emphasizes the possible modes of failure of a unitized regenerative fuel cell (URFC) when operated in fuel cell as well as in electrolysis mode at different temperatures viz. 30 C and 60 C. The carbon based catalyst (Pt/C) and diffusion layers are used to characterize the degradation of the URFCs. The electrolysis mode of operation is found to dominate the root cause of failure with increase in temperature. Agglomeration and loss of catalyst along with delamination of electrode from membrane are observed. Membrane degradation owing to it's structural as well as chemical damage is seen to be prominent at higher temperature. Characterization techniques such as SEM, TEM and ICP-AES confirm the study showcasing the effect.

Experimental investigation on voltage response to operation parameters of a unitized regenerative fuel cell during mode switching from fuel cell to electrolysis cell

“…The existing researches focused on the bi‐functional electrode, gas diffusion layer (GDL), flow field design, operating pressure etc. Some researchers investigated the configuration of the bi‐functional oxygen electrode; others studied the proportion of platinum and other noble metal alloy catalyst. The GDL is a significant component and possesses the function of collecting current and gas diffusion.…”

Experimental investigation on two-phase flow in a unitized regenerative fuel cell during mode switching from water electrolyzer to fuel cell

“…However, too high temperature such as 80°C causes insufficient water in WE mode without water supply and membrane dehydration in FC mode. In the work of Bhosale et al, performance decrease occurred in both 30°C and 60°C. High temperature accelerated the decrease, which was caused by the delamination of membrane electrode assembly and corrosion of carbon.…”

Preparation methods of membrane electrode assemblies for proton exchange membrane fuel cells and unitized regenerative fuel cells: A review

“…Despite various coating methods available; rolling, spraying and brushing methods have been adopted both for small (< 50 cm 2 ) as well large size (> 50 cm 2 ) GDLs during preparation [17,[98][99][100]. In case of PEMFCs, carbon paper or cloth is predominantly selected as base substrate for coating MPL (usually made from Vulcan XC-72).…”

“…Unitized regenerative fuel cells (URFCs) [16,17] are the extension of conventional proton exchange membrane fuel cells with the additional ability of electrolyzing the water with the help of heat and electrical energies as an input (Fig. 1a).…”

“…1a schematically explains the working of a URFC in respective modes. PEMFCs are a mature technology and have found themselves in marine applications [17,18], portable power sources [19,20], aerospace [21], vehicles etc. [22].…”