"In the development of a sodium ion capacitor there are several challenges that need to be faced"

The exploration of sodium-ion capacitors stands out as a promising avenue towards more environmentally friendly and efficient energy storage systems. Dr. María Arnaiz, a postdoctoral researcher at CIC energiGUNE and project´s prototyping work package, sheds light on the intricate journey of prototyping sodium-ion capacitors, revealing the complex challenges and innovative strategies that underpin this groundbreaking research.

• What are the challenges of prototyping?

In the development of a sodium ion capacitor there are several challenges that need to be faced. To begin with, electrode fabrication by aqueous processing is a big challenge itself, mainly regarding the positive electrode, where a microporous material such as activated carbon will be used. Moreover, the introduction of a pre-sodiation agent in the formulation of the positive electrode requires the selection of specific binders and other components for its appropriate development. Furthermore, in order to develop a successful prototype, it is very important to define the appropriate mass balance between electrodes in order to obtain the maximum performance without impacting the durability of the system, in which the appropriate selection of the electrolyte also plays a key role. In this regard, the maximum performance will also be obtained by ensuring that the system shows the minimum resistance. To this end, appropriate current collector and electrode adhesion and cohesion quality must be ensured. Finally, in sodium ion capacitors, some gas generation might be occurring during the pre-conditioning step, thus, an appropriate handling of it will also be necessary to ensure the success of the developed prototypes.

The path to realizing the full potential of sodium-ion capacitors is fraught with challenges, yet it is one that the MUSIC Project, navigates with unwavering determination and innovation. Each hurdle presents an opportunity to refine our approach and deepen our understanding, moving us closer to the goal of a sustainable and efficient energy future. The insights provided by Dr. Arnaiz not only highlight the technical complexities involved in prototyping this technology but also underscore the collaborative spirit and expertise driving the MUSIC Project forward.