Dr. Rebeca Marcilla will give two talks on "Redox-active Polymer for more Sustainable Batteries" and "Membrane-free Redox Flow Batteries". All are welcomed to join. Please register here (contact form) if you wish to attend the lecture.

Speaker : Dr. Rebeca Marcilla (Senior Researcher, IMDEA Energy Institute)

As for further information on her research project, please visit:
Unit of Electrochemical Processes, IMDEA Energy Institute

Lecture (1) on Nov. 9, 2023

“Redox-active Polymer for more Sustainable Batteries”

（Abstract）
The expected growth over the next few years in the battery sector is huge, with approximately 7 million tons of new batteries manufactured per year. This growth is mainly triggered by the deployment of the electric vehicle and by the energy storage coupled to wind and photovoltaic generation. However, the massive development of the sector could become an environmental problem since most commercial batteries are based on inorganic materials such as lithium, nickel and cobalt in lithium-ion batteries or vanadium in flow batteries. These materials are scarce, their production in some cases is not sustainable and some are even toxic. In this context, the replacement of these materials by organic compounds based on elements as abundant as C-H-O-N has become a very promising alternative [1]. In this talk, I will focus on exposing the enormous structural and synthetic possibilities of redox-type polymers and their application in different types of batteries. I will present an overview of the efforts of my group to develop more sustainable batteries using redox-active polymer electrodes. First, I will introduce the different polymer structures (linear, porous, nanoparticles) containing redox active functionalities (quinones, phenazynes, etc) that we have developed in the last years. Among the huge variety of redox-active polymers, I will present our recent research on Conjugated Microporous Polymers that combine extended π-conjugation with inherent 3D microporosity, large specific surface area and high stability. Then, I will focus on the electrochemical properties of different polymer chemistries&structures in different electrolytes and their potential application in several battery technologies including Li-ion, multivalent, aqueous, all-polymer, etc.

Lecture (2) on Nov. 10, 2023

 “Membrane-free Redox Flow Batteries”

（Abstract）
The implementation of renewable energies (solar, wind, etc) is driven the development of new energy storage systems that can mitigate their inherent intermittency solving the mismatch between the energy demand and production. Among different systems, electrochemical energy storage devices stand out due to their efficiency, flexibility and modularity. Specifically, Redox Flow Batteries (RFB) are an unique technology able to decouple energy and power which makes them versatile and adaptable to different applications. Nevertheless, although they are commercially available, their implementation is limited by the high cost and issues associated with some components such as the vanadium-based electrolytes and Nafion ion-exchange membranes. In this regard, our approach to overcome these limitations is the development of membrane-free flow batteries based on immiscible/biphasic electrolytes containing organic active species. The selective thermodynamic separation of the active species in two immiscible liquid phases made possible to eliminate any membrane or physical barrier in our batteries. In this talk, I will present an overview of the different membrane-free batteries developed in our group, including those based on biphasic aqueous electrolytes. Thanks to a patented flow-cell reactor, we were able to develop the first example of aqueous membrane-free battery operating under flow conditions. The results show high coulombic efficiency (94%), capacity utilization (98%), and stable long-term performance over 250 cycles. The fundamental challenges and the last advances in this innovative concept will be discussed with especially attention to the strategies designed to mitigate the inherent self-discharge of this membrane-free battery technology.