"The MUSIC Project´s strategy is targeting the use of sacrificial molecules with high irreversible capacity"

In our ongoing pursuit of advancements in energy storage technologies, the MUSIC project stands at the forefront, aiming to revolutionize sodium-ion capacitors. As part of our endeavor, we had the privilege to engage in a stimulating conversation with Thierry Brousse from the University of Nantes, a key figure within the project. In this interview segment, we delve into the intricate realm of pre-sodiation and its significance in dual carbon SICs (Sodium-Ion Capacitors).

What is the role that pre-sodiation plays in a dual carbon SIC??

Unlike in sodium-ion batteries, sodium-ion capacitors do not have a source of sodium cations when assembled. Only the electrolyte could provide sodium ion to the hard carbon negative electrode upon a first conditioning cycle but this will lead to a depletion of cations from the electrolyte followed by a drastic increase in ionic resistance. Thus a pre-sodiation step is required to provide sodium cations to the negative electrode without altering neither the ionic conductivity of the electrolyte nor the positive electrode. A genuine way to fulfill these requirements is to use pre-sodiation compounds that will be added to the positive electrode and that will only be used once upon the first charge of the device to provide sodium cations to the hard carbon electrode. Unlike lithium-ion capacitors, this pre-sodiation step cannot be safely achieved by using a sacrificial metallic sodium electrode.

What is the MUSIC strategy for pre-sodiation?

MUSIC strategy is targeting the use of sacrificial molecules with high irreversible capacity. They will be added to the positive electrode formulation and they will deliver their sodium ions only during the first charge of the device. The expectations are that once this step is achieved, the de-sodiated molecules will not have any influence on the electrochemistry of the cell, neither on its performance. The MUSIC project is also dedicated to the search of molecules issued from bio-resources. The interest in such compounds is that the recycling process will not have to deal with transition metal cations, but only with light elements that can be easily handled.

The insights shared by Thierry Brousse shed light on the pivotal role of pre-sodiation in enhancing the performance and longevity of dual carbon SICs within the MUSIC project. By employing sacrificial molecules with high irreversible capacity, coupled with a strategic focus on bio-sourced compounds, the project aims to achieve unparalleled efficiency while ensuring eco-friendly practices. As we continue to push the boundaries of energy storage innovation, collaborations and expertise like Thierry´s pave the way for a sustainable and electrifying future.