Intitulé du sujet: Development of Intrinsically Conductive Organic Cathodes for Advanced Rechargeable Batteries
Sujet
Codirection: Benoit Limoges (directeur de th?se)
Nombre de mois: 48 mois
Ecole Doctorale: ED 388 - Chimie physique et Chimie analytique de Paris centre
Unité de recherche et équipe:
The PhD student will join the TERE (Electron Transfer and Electrochemical Reactivity) team of the ITODYS laboratory, to which the current Laboratory of Molecular Electrochemistry will be merged from January 1st 2025. The PhD student will be under the supervision of Dr. Benoit Limoges, Research Director at Centre National de la Recherche Scientifique (CNRS), and co-supervision of Mathieu Branca, Assistant Professor at University Paris City.
This team currently comprises 5 permanent staff (1 CNRS Research Director, 1 Professor, 2 Assistant Professors and 1 assistant engineer), 1 post-doc and 4 PhD students.
The team has an internationally recognized expertise in electrochemistry of molecules and materials and has made several important fundamental contributions in the field of rechargeable aqueous batteries, notably by providing new insights in the charge storage mechanisms of different metal oxide electrode materials (TiO₂, MnO₂, WO3) as well as quinone-based composite electrodes. Among our most significant findings is on the role that multivalent metal cations can play as proton donors in the charge storage mechanism of a wide range of electrode materials in aqueous electrolytes. This better fundamental understanding of charge storage mechanisms and the role played by the electrolyte constituents has enabled us to propose technological advances.
List of 5 recent publications in the field:
[5] A unified charge storage mechanism to rationalize the electrochemical behavior of quinone-based organic electrodes in rechargeable aqueous batteries. W. Wang, V. Balland, M. Branca, B. Limoges, J. Am. Chem. Soc., 2024, 146, 15230–50.
[6] Impact of Reversible Proton Insertion on the Electrochemistry of Electrode Materials Operating in Mild Aqueous Electrolytes: A Case Study with TiO2. N. Makivic, K. D. Harris; J-M. Tarascon, B. Limoges, V. Balland, Adv. Energy Mater., 2023, 13, 2203122.
[7] Evidence of Bulk Proton Insertion in Nanostructured Anatase and Amorphous TiO2 Electrodes. N. Makivic, J-Y Cho, K. D. Harris; J-M. Tarascon, B. Limoges, V. Balland, Chem. Mater., 2021, 33, 3436–48
[8] Accessing the Two-Electron Charge Storage Capacity of MnO2 in Mild Aqueous Electrolytes. M. Mateos, N. Makivic, Y-S Kim, B. Limoges, V. Balland, Adv. Energy Mater., 2020, 10, 2000332.
[9] On the Unsuspected Role of Multivalent Metal Ions on the Charge Storage of a Metal Oxide Electrode in Mild Aqueous Electrolytes. Y-S Kim, K. D. Harris, B. Limoges, V. Balland, Chem. Sci., 2019, 10, 8752–63. (part of the 2019 Chemical Science HOT Article Selection)
Coordonnées de l’équipe:
Dr. Benoit LIMOGES - limoges@u-paris.fr directeur de thèse
Dr. Mathieu BRANCA - mathieu.branca@u-paris.fr co-encadrant
Secteur: Sciences Physiques et Ingénierie / Physical sciences and Engineering
Langue attendue: Anglais
Niveau de langue attendu: B2
Description
Description du sujet:
General context
Advances made so far in energy storage technologies have underscored the need to explore alternatives to traditional lithium-ion batteries (LIBs), which are facing limitations in terms of cost, durability, and scalability due to their reliance on elements that are not only insufficiently abundant, but also ethically (e.g. cobalt) and environmentally problematic. As a response, "beyond Li-ion" technologies are gaining significant attention, with particular emphasis on rechargeable aqueous zinc batteries. These systems offer compelling advantages, including low cost, high safety, and high ionic conductivity due to the water-based electrolytes. Moreover, zinc metal anodes provide an excellent specific capacity (820 mAh.g⁻¹ and 5855 mAh.cm⁻³), a favorable redox potential (−0.76 V vs. standard hydrogen electrode), and good stability in aqueous conditions. However, one of the critical challenge of these aqueous zinc-based batteries is the development of suitable cathode materials. Organic compounds have recently emerged as promising candidates due to their electrochemical activity and flexibility through molecular engineering. Modifying substituent groups and structural frameworks allows for precise control over electrochemical behavior. But despite some interesting developments, [1] organic cathodes suffer from low electrical conductivity, requiring large amounts of conductive carbons in the composite electrode material (often exceeding 30 wt. %) to achieve viable performance. This requirement inherently limits practical capacity and energy density, motivating research into more efficient strategies.
One promising avenue is to exploit organic redox-active compounds with intrinsic semiconducting properties, enabling electrons transport over long distances. This can be achieved with organic compounds having planar and aromatic structures, which, by p-electron delocalization, ensures a certain degree of electronic conductivity in the condensed phase of these molecules. Thanks to such molecules, it will be then possible to reduce the amount of conductive carbon required to ensure the good conductivity of organic composite electrode materials, and thus to significantly improve the gravimetric capacity of zinc-organic batteries, and hence their energy density.[2],[3]
Overall, the development of intrinsically conductive organic materials represents a critical step toward the practical realization of high-performance, cost-effective, and scalable cathodes for aqueous zinc batteries and other next-generation energy storage technologies. Such materials combine environmental sustainability with promising electrochemical properties, marking a pivotal shift toward greener, more efficient energy storage solutions.
Research project
The PhD project aims to develop and investigate organic electrodes based on organic molecular semiconductors such as TAQ,[2] and TDT,[3] and HAT[4], primarily - but not exclusively - for use in aqueous zinc batteries. The objectives include achieving high mass loading, high areal capacity, and excellent cycling stability while minimizing the use of conductive additives. To meet these goals, the PhD candidate will have to focus on the preparation of composite electrode materials, exploring their physicochemical properties and identifying the key parameters driving optimal performance.
The primary characterization techniques will include galvanostatic charge/discharge, cyclic voltammetry, chronoamperometry, spectroelectrochemistry, as well as spectroscopic methods such as UV-Vis, Raman, IR, and XRD. For students interested in organic synthesis, the project may also involve the design and synthesis of π-conjugated redox-active structures.
[1] P. Poizot et al., Opportunities and Challenges for Organic Electrodes in Electrochemical Energy Storage, Chem. Rev. 2020, 120, 14, 6490.
[2] T. Chen et al., A Layered Organic Cathode for High-Energy, Fast-Charging, and Long-Lasting Li-Ion Batteries, ACS Cent. Sci., 2024, 10, 569-578.
[3] L. Lin et al., A semi-conductive organic cathode material enabled by extended conjugation for rechargeable aqueous zinc batteries, Energy Environ. Sci., 2023, 16, 89.
[4] Y. Zhang et al., Duodecuple H-Bonded NH4+ Storage in Multi-Redox-Site N-Heterocyclic Cathode for Six-Electron Zinc–Organic Batteries, Adv. Funct. Mater., 2024, 2405710.
Compétences requises:
The ideal PhD candidate should have solid knowledge in electrochemistry, electrochemical charge storage systems, electrode materials, material chemistry and material characterization. She/he should demonstrate a strong interest for the field of rechargeable batteries. Experience in organic batteries and/or organic synthesis would be a plus.
Références bibliographiques:
[1] P. Poizot et al., Opportunities and Challenges for Organic Electrodes in Electrochemical Energy Storage, Chem. Rev. 2020, 120, 14, 6490.
[2] T. Chen et al., A Layered Organic Cathode for High-Energy, Fast-Charging, and Long-Lasting Li-Ion Batteries, ACS Cent. Sci., 2024, 10, 569-578.
[3] L. Lin et al., A semi-conductive organic cathode material enabled by extended conjugation for rechargeable aqueous zinc batteries, Energy Environ. Sci., 2023, 16, 89.
[4] Y. Zhang et al., Duodecuple H-Bonded NH4+ Storage in Multi-Redox-Site N-Heterocyclic Cathode for Six-Electron Zinc–Organic Batteries, Adv. Funct. Mater., 2024, 2405710.
