Date published: Nov. 4, 2025

Summary

A Zirfon separator for alkaline water electrolyzers is modified with catalyst nanoparticles on its anode side to catalyze crossover gases into water, preventing flammable mixtures and enhancing safety.

Commercial Applications

  • Alkaline water electrolysis
  • Zirfon separator manufacturing
  • Alkaline rechargeable batteries, alkaline fuel cells

Benefits

Significantly reduces hydrogen crossover by over 90%, enhancing safety by preventing flammable gas mixtures.

Background

Liquid alkaline water electrolyzers (LAWEs) are a hydrogen production technology through water electrolysis using an alkaline electrolyte. They account for around 60% of the water hydrolysis market globally and are known for being lower-cost than other electrolysis technologies. However, they still face safety concerns, due to the mixing of hydrogen and oxygen gas, which can be highly flammable. This danger is due to the use of a porous separator between the anode and cathode, with the most widely used of these separators being the Zirfon diaphragm (polysulfone matrix and zirconia powder). 

Technology Description

Scientists at Berkeley Lab have developed a strategy to mitigate gas crossover with a functionalized Zirfon separator that allows for highly efficient catalytic reaction for liquid alkaline water electrolyzers (LAWEs). This separator features a sparse, binder-free distribution of inter-connected catalyst nanoparticles that catalyze the recombination of crossover hydrogen and oxygen into water, preventing flammable gas mixtures without creating electronic pathways or compromising separator integrity. The absence of polymeric binders ensures alkaline stability and low ionic resistance.

Tests show that the invention limits more than 90% of the crossover at the same cell current densities.

Development Stage

TRL 3: Proof of concept

Inventors

Xiong Peng

Haotian Liu

IP Status

Patent pending

Opportunities

Available for licensing or collaborative research