Cerium Oxide–Polysulfone Composite Separator for an Advanced Alkaline Electrolyzer

Abstract

The intermittent and volatile nature of renewable energy sources threatens the stable operation of power grids, necessitating dynamically operated energy storage. Power-to-gas technology is a promising method for managing electricity variations on a large gigawatt (GW) scale. The electrolyzer is a key component that can convert excess electricity into hydrogen with high flexibility. Recently, organic/inorganic composite separators have been widely used as diaphragm membranes; however, they are prone to increase ohmic resistance and gas crossover, which inhibit electrolyzer efficiency. Here, we show that the ceria nanoparticle and polysulfone composite separator exhibits a low area resistance of 0.16 Ω cm2 and a hydrogen permeability of 1.2 × 10–12 mol cm–1 s–1 bar–1 in 30 wt% potassium hydroxide (KOH) electrolyte, which outperformed the commercial separator, the Zirfon PERL separator. The cell using a 100 nm ceria nanoparticle/polysulfone separator and advanced catalysts has a remarkable capability of 1.84 V at 800 mA cm−2 at 30 wt% and 80 °C. The decrease in the average pore size of 77 nm and high wettability (contact angle 75°) contributed to the reduced ohmic resistance and low gas crossover. These results demonstrate that the use of ceria nanoparticle-based separators can achieve high performance compared to commercial zirconia-based separators.

Pristine and Modified Porous Membranes for Zinc Slurry–Air Flow Battery

“…Similarly, electrolyte uptake-induced zero dimensional change has been reported for Celgard ® 3501 elsewhere [46]. volume porosity (v/v) * 100 (Density used: PP = 0.92 g cm −3 and Zirfon ® = 2.37 g cm −3 , apparent density [47]) and volume porosity are provided in Table 2. ** Porosity filled with the electrolyte are not determined as their porosity volumes are not available.…”

“… * Percent of (Density used: PP = 0.92 g cm − ³ and Zirfon ® = 2.37 g cm − ³, apparent density [ 47 ]) and volume porosity are provided in Table 2 . ** Porosity filled with the electrolyte are not determined as their porosity volumes are not available.…”

Highly Efficient Alkaline Water Electrolysis Using Alkanolamine-Functionalized Zirconia-Blended Separators

“…Among the reported works, chemical modification has included plasma-initiated grafting of acrylic acid, sulfonation, and usage of N , N , N ′, N ′-tetramethyl-1,6-hexanediamine to cross-link . Particles chosen for physical coacervation are ZrO 2, − CeO 2, Al 2 O 3, cellulose nanocrystals (CNCs), and poly­(vinylpyrrolidone) (PVP) particles …”

Zirconia Toughened Alumina-Based Separator Membrane for Advanced Alkaline Water Electrolyzer

“…Many techniques have been developed to improve the surface characteristics of polysulfone such as sulfonation [ 51 ], crosslinking [ 52 ], or blending [ 53 ]. Several inorganic materials such as ZrO 2 [ 54 , 55 ], CeO 2 [ 56 ], TiO 2 [ 57 , 58 ], yttria-stabilized zirconia commonly known as (YSZ) [ 59 ], and barite mineral (BaSO 4 ) have been added as a filler in the polymer matrix [ 60 ]. However, these filler materials exhibited a significant reduction in their mechanical stabilities due to agglomeration and improper mixing with the polymer matrix [ 45 , 61 , 62 ].…”