Development of novel anion exchange membranes for alkaline water electrolysis with employment of DC electric fi

Abstract

Nowadays, Hydrogen production is an important piece in energy transition system and holds a significant place in various industries. This gas is precursor for producing valuable compounds in the chemical industry and serves as a clean fuel, enabling efficient electricity generation when used with fuel cells. However, majority of its production still relies on reforming and gasification of non-renewable sources. A sustainable pathway for Green Hydrogen production through water electrolysis already exists. However, scaling up and commercializing this technology represents challenge in meeting global demand, which was reported to be around 95 million tonnes in 2022. Commercially available water electrolysis done in acidic environment is robust, however rather expensive. Anionic Exchange Membrane Water Electrolysis (AEMWE) is available alternative, but still not fully developed to be used on big industrial scales. AEMWE offers reduced cost as this technology does not require usage of expensive noble metal catalysts used in acidic electrolysis. Focus of the AEMWE research area is Anionic exchange membrane (AEM) as high values of conductivity of hydroxide ions could lead to fair technical competitiveness of alkaline and acidic electrolysis. However, the majority of currently available AEMs lack the desirable properties, such as mechanical/alkaline stability as well as anionic conductivity.
One of the promising novel techniques for membrane fabrication consists of membrane casting with employing DC electric field, which enhances charged polymer channel orientation. Reports have shown that polymer ion channels in random direction may cause slower migration and consequently lower values for conductivity. On the other hand, it has been proven that DC treated membranes can yield up to three times higher values for conductivity of OH− ions. Therefore, researching optimal DC values for casting significantly impacts electrochemical cell performance.
This thesis report focuses on fabrication, characterisation and performance evaluation of the cast membranes with DC empolyment, prepared from cationic polymer kindly provided from industrial collaborator. Furthermore, an attempt will be made to assess competitiveness between produced and commercially available membranes. Finally, future suggestions for research directions and alternative membrane fabrication techniques will be provided, as these could offer valuable insights for further exploration in this field.