Membrane layout stops crossover in polysulfide redox flow batteries

Apr 20, 2021 04:56 PM ET
  • Two scientists at the Chinese University of Hong Kong have established a new membrane style that prevents crossover in polysulfide redox flow batteries.
Membrane layout stops crossover in polysulfide redox flow batteries
Image: Nature Energy (2021)

In their paper released in the journal Nature Energy, Zhejun Li and Yi-Chun Lu define their collaborate with the new membrane layer style. Wei Wang with Northwest National Laboratory has actually published a News & Views piece in the same journal concern describing problems with polysulfide redox flow batteries and also the work by Li and also Lu to conquer them.

Back in the mid-1970s, NASA engineer Lawrence Thaller developed the concept of a redox flow battery. Because that time, such batteries have been widely used in large-scale applications such as backing up power grids. This is since they are simple to scale approximately huge levels-- the principle includes storing electrolytes in decentralized exterior storage tanks. In more recent times, researchers have wanted to build polysulfide redox flow batteries since they would certainly be more affordable to construct and maintain. A plant was constructed to examine the concept, however sadly, doing so disclosed an obvious weakness of the product-- crossover of polysulfide types, which caused a really brief life process. In this brand-new initiative, the researchers have gotten over the problem of crossover with the development of a new membrane style.

The style includes using a layer of Ketjen black carbon affixed to the surface area of a Nafion membrane layer utilizing polyvinylidene fluoride. The scientists note this was done by decrease casting the carbon slurries onto both sides of the membrane layer. They also keep in mind that due to the fact that the membrane layer was so large, the surface area throughout it was able to function as a trap for polyiodide and also polysulfide ions. When saturation happened, they mentioned, the anions were blocked, maintaining them from relocating onto the membrane layer, and also thus no crossover can happen. The researchers note that the high conductivity of the carbon on the membrane layer gets over the reduced conductivity of the underlying membrane layer; therefore, it is not destructive to the feature of the membrane as would certainly be the case in membranes where trapping typically happens.

The scientists evaluated the layout in both flow and also static polysulfide-- iodide cells as well as discovered that crossover did not take place, which indicated boosted life process numbers-- confirming the style viable.