Electrochemical Analysis of Polymer Membrane with Inorganic Nanoparticles for High-Temperature PEM Fuel Cells

Abstract

In order to solve the challenge that battery performance rapidly deteriorates at a high temperature condition of 100 °C or higher, ZrO2-TiO2 (ZT) with various Zr:Ti ratios synthesized by a sol-gel method were impregnated in a Nafion membrane. Through material characterization, a unique ZT crystal phase peak with a Zr-O-Ti bond was identified, and the band range associated with this bond and intrinsic functional group region could be identified. These prepared powders were blended with 10% (w/w) Nafion-water dispersion to prepare composite Nafion membranes (NZTs). The water uptake increased and the ion exchange capacity decreased as the TiO2 content increased in the NZTs in which particles were uniformly distributed. These results were superior to those of the conventional Nafion 112. The electrochemical properties of all membranes was measured using a polarization curve in a single cell with a reaction area of 9 cm2, and the operating conditions in humidified H2/air was 120 °C under 50% relative humidity (RH) and 2 atm. The composite membrane cell with nanoparticles of a Zr:Ti ratio of 1:3 (NZT13) exhibited the best electrochemical characteristics. These results can be explained by the improved physicochemical properties of NZT13, such as optimized water content and ion exchange capacity, strong intermolecular forces acting between water and nanofillers (δ), and increased torsion by the fillers (τ). The results of this study show that the NZT membrane can replace a conventional membrane under high-temperature and low-humidity conditions. To examine the effect of the content of the inorganic nanomaterials in the composite membrane, a composite membrane (NZT-20, NZT-30) having an inorganic nano-filler content of 20 or 30% (w/w) was also prepared. The performance was high in the order of NZT13, NZT-20, and NZT-30. This shows that not only the operating conditions but also the particle content can significantly affect the performance.

Hydrophilic fillers for anione exchange membranes of alkaline water electrolyzers

“…Currently, this type of diaphragm is the main one for industrial alkaline water electrolyzers [10]. The hydrophilic filler ZrO2 -TiO2 is also used in fuel cells with a solid polymer electrolyte [11]. Currently, studies are underway on the use of zirconium hydroxides, magnesium oxides, magnesium hydroxides, titanium oxides, titanium hydroxides and barium sulfate as a hydrophilic inorganic filler [12].…”

Polymer Electrolyte Membranes Containing Functionalized Organic/Inorganic Composite for Polymer Electrolyte Membrane Fuel Cell Applications

“…In addition, when the particle size of non-functionalized SiO 2 is larger than the size of ionic clusters formed by the hydrophilic/hydrophobic phase separation of the polymer matrix, the proton conducting channels were blocked by SiO 2 resulting in the degradation of proton conductivity of the corresponding composite membranes [124]. To address these problems, many approaches have been investigated for functionalization of SiO 2 [125][126][127].…”

Enhancing Water Retention, Transport, and Conductivity Performance in Fuel Cell Applications: Nafion-Based Nanocomposite Membranes with Organomodified Graphene Oxide Nanoplatelets

“…The latter strategy has progressively emerged as one of the most promising since the presence of inorganic nanofillers inside the polymer matrix increases the mechanical stability of the membrane while simultaneously enhancing its water-retaining capability and thus the proton conductivity [22,23]. For instance, Choi et al prepared a composite membrane based on Nafion/TiO 2 -ZrO 2 with varying ratios of Ti/Zr and tested it at high temperatures and low relative humidity [24]. They reported an enhanced performance of the composite membranes, with a TiO 2 -ZrO 2 content of up to 30% of w/w.…”