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Subject of the thesis

Ionic Liquid Crystals: Towards tuneable-by-design electrolytes

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Published on 9 December 2019
Funding Offer:
Funding type: ANR (National Agency of Research)/PhD Fellowship
Funding amount: 2135 € gross / month

Application deadline: May 30, 2020 @ 6:00 pm (CET).
Duration: 36 months
Start date: ASAP

Position summary
This is a full-time temporary employment, and the position is limited to a maximum of three years. The PhD position is immediately available. The PhD can be preceded by a researcher master internship.

Eligibility criteria:
We are looking for a talented and motivated PhD student willing to contribute to a project focused on the relationship between multiscale structure and ionic transport in electrolytic soft matter.
The PhD candidate is required to hold a Master degree in (Electro-)Chemistry, Materials Science or another relevant discipline dealing with functional soft matter. A previous experience in the synthesis and/or multiscale structure (SAXS/WAXD)/property (ionic or electronic conductivity) correlations of functional (i.e. electronically/ionically conducting) materials being especially appreciated. A demonstrated ability to perform independent work, to work across borders of chemistry and physics of functional soft maters, and excellent communication and writing (English) skills are equally important criteria with respect to academic qualifications and scientific merit for the selection of the PhD candidate. The successful candidate is truly interested in hard laboratory work, is not afraid to face new challenges, is personally mature, and is strongly motivated and self-driven. The friendly environment of SyMMES provides a number of different theoretical skills and experimental expertise as well as it gathers many young and engaged research leaders.

Major responsibilities
The PhD is expected to actively drive forward a project focused on the transport mechanism in ionic liquid crystals. This project is mainly experimental and based on the use of diverse techniques such as impedance spectroscopy, home-made SAXS/WAXS, POM, NMR spectroscopy, diffusion NMR and thermal analysis, but through external collaborations the use of computational methods and large-scale facilities will also be explored. The student must therefore be able to tackle a diversity of methods and approaches. Along with performing experiments and analysing data, the candidate will also be responsible for communicating clearly and regularly the progress of the work, contributing to relevant national and international conferences, and writing high-quality scientific papers. The student will also have to follow courses as part of the education. It is important to recognize that this position gives merits for future research activities within the academia or in the industrial/public sector.

Selection process
The deadline for application is June 30, 2020 @ 6:00 pm (CET) (November 1, 2020 for the Master position). We encourage candidates to apply as soon as possible. The search for candidates will continue until the position is filled. Applicants should provide an e-application file combining a curriculum vitae, a letter of motivation (1-3 pages where you introduce yourself and present your qualifications. Previous research fields and main research results. Future goals and research focus. Are there any specific projects and research issues you are primarily interested in?), a summary of their research experience, and a list of publications. A single pdf should be addressed both to Dr. Manuel Maréchal  & Dr. Patrice Rannou.  The applicants should arrange that at least two reference letters are sent directly to the contact address above.

Rationale: Through enabling the hierarchical self-assembly of ionic liquid crystals up to the meso/micro-scopic scale though ac-electric field-directed long-range organisation, the cutting-edge proposed project aims to go beyond the state-of-the-art level of ionic transport performances through a better understanding of the multiscale structure/transport interplay, notably by directing the self-assembly of long-range ordered nanoscale ionic pathways. The innovative strategy of defect management in functional materials, which plays crucial roles in many areas (e.g. doping in nanoelectronics) of nano-science/technology, is applied here in to directional confined ionic transport (nanoionics) to fulfil the pressing scientific challenge of lab-to-fab technology transfer towards electrolytes 2.0 for next generation electrochemical energy generation (e.g. DSSC) & storage (e.g. battery) solutions.

Research Topic: Solid Polymer Electrolytes (SPEs) with high ionic conductivity and appropriate mechanical properties are envisioned as alternatives to liquid electrolytes for a safer generation of high performance electrochemical energy storage devices. Towards this goal, intensive research efforts onto new generations of SPEs have flourished worldwide since the first suggestion in the late 70s by Dr. M. Armand and co-workers. Yet, simultaneously achieving a full control of mechanical properties towards the desired level together with fast ionic transport still remains to date a red-brick wall; preventing the advent of a competitive SPE-based solution for electrochemical energy devices. Within the different material strategies developed to date, such as PEO-based homo and block copolymer anionic or cationic salts, single-ion polymer electrolytes (SIPEs) and polymeric ionic liquids (PILs) to name a few, SIPEs hold promises owing to their tunable by design material aspect (allowing the encoding of specific morphologies and physicochemical properties inherited from their precisely defined macromolecular architectures) coupled with its single ion (e.g. lithium for secondary lithium-ion battery or oxonium for fuel cell) transport capability. Using a series of single-ion precise copolymer electrolytes (SIPRECE) within which ionic functions will be precisely positioned onto a polymeric backbone ensuring the appropriate properties of ion conduction and multiscale organization, we will perform in depth structure/property correlation studies to evaluate the performances of this new type of SPEs. Multi-scale variable-temperature and relative humidity (when appropriate) WAXS/SAXS characterizations will be performed to determine the hierarchical self-organization of SIPRECE model systems across nano->meso->microscopic length scales. In-plane and through-plane ionic conductivity studies will be also conducted on a customized platform combining Electrochemical Impedance Spectroscopy (EIS), Polarized Optical Microscopy (POM), without or with electric field alignment, with the goal to assess the presence or absence of grain boundaries onto the measured ionic conductivity levels of non vs. fully-aligned SIPRECE model systems.

Thesis overview: This research project aims at generating and studying libraries of single-cation (e.g. Li+, Na+, etc.) conducting polymerized thin films. Thermotropic ionic liquid crystals (TILCs) featuring photo-crosslinkable end-moieties will be photo-crosslinked in situ for their use at the heart of next generation solid-state batteries. Beyond synthetic aspects, interplay between structure & transport properties will be studied to reveal directed 1D vs. 2D vs. 3D. ionic transport features within solid-state electrolytes encoding precise morphologies.

Objectives: This basic research-oriented project focusing onto soft-matter based advanced electrolytes concerns the development of electrochemical energy devices 2.0. It aims at developing families of tunable-by-design ionically conducting electrolytes relying on simple to implement, scalable and industry-compliant elaboration processes. Its overarching goal is to deliver proof of concept demonstration of efficient nanoconfined ionic transport going beyond the current state-of-the-art in reply to mankind’s energy needs (UN SDG N°7). Fulfilling this goal requires the synthesis of tailored-made electrolytes to addresses two fundamental questions for advanced nanostructured organic electrolytes: i) the role of (1D vs. 2D vs. 3D) dimensionality onto the percolation and nanoconfinement of charge carriers within multiscale phase-segregated materials with insulating & conducting sub-phases & ii) the mosaicity & the defect management in functional soft matter.

Research Methodology: A multimodal experimental approach coupling complementary techniques (Polarized Optical Microscopy (POM), scattering techniques, NMR, impedance/dielectric spectroscopy) will be applied to correlate structures and transport properties across all relevant length scales. The main goal is to perform thorough characterizations of this generic family of advanced solid electrolytes aiming at surpassing the current scientific and technological hurdles that limit the practical (scale-up) implementation of existing technologies into numerous applications (e.g. ion transport, water filtration or molecular separation). The large variety of available synthons mastered by researchers of the UMR5819-SyMMES lab will help to generate generic families to evaluate and optimize the scope and performance of single-ion solid electrolytes. A dedicated multimodal platform already implemented at the UMR5819-SyMMES (CEA/CNRS/UGA) lab since 2016 thanks to the CNRS funding of the exploratory instrumental project PLEO for which the thesis Advisor is the PI, will be used during this PhD work. This platform works in the direct space (POM) and gives access to the carrier dynamic through impedance/dielectric spectroscopy (over the 1µHz-50 MHz frequency range) while simultaneously opening the possibility of applying an ac-electric field. The actual challenge set is to additionally acquire structural information in the reciprocal space using (GI)WAXS/SAXS ((Grazing Incidence) Small- and Wide X-ray Angle Scattering). This platform allows also the determination of both the ionic conductivity and structural organization in the in-plane vs. through-plane configurations, to reveal potential anisotropic features.

Skills required: 1) Organic Chemistry: (Multi-Step) synthesis and purification of functional materials 2) Electrochemistry of electrolytes (dielectric/impedance spectroscopy, electrochemical characterisations) 3) X-Ray scatterings (SAXS/WAXS) 4) Soft Matter knowledge (polymer, gel, liquid crystals)

Bibliography:[1] L. Santonja-Blasco et al., Adv. Polym. Sci. 276 133-182 (2017)
[2] G. Portale et al., Adv. Polym. Sci. 277 127-166 (2017)
[3] G. He et al., Adv. Mater .27, 5280-5295 (2015)
[4] D.T. Hallinan & N.P. Balsara, Annu. Rev. Mater. Res. 43, 503-525 (2013) 
[5] Z. Xue et al., J. Mater. Chem. A 3, 19218-19253 (2015) 
[6] D. Golodnitsky et al., J. Electrochem. Soc. 162, A2551-A2566 (2015) 
[7] S. Cheng et al., RSC Adv. 5, 48793-48810 (2015).

1: Single-ion precise electrolytes. 2: Ionic transport. 3: Long-range organization. 4: Mosaicity . 5: Structure/transport relationship. 6: ac-electric field driven self-assembly

Level of French required: B1 (intermediate)
Level of English required: C2 (proficiency)
Opportunity to make your thesis in English

PhD Supervisors
Dr. Patrice RANNOU

CNRS senior researcher, PhD/HDR
Dr. Patrice RANNOU
CNRS Director of Research, PhD/HDR

UMR5819-SyMMES (CEA/CNRS/Univ. Grenoble Alpes), Systèmes Moléculaires et nanoMatériaux pour l'Energie et la Santé
17 avenue des martyrs
F-38054 GRENOBLE Cedex9

Host institution:
COMUE-UGA: Communauté Université Grenoble Alpes
CNRS: Centre National de la Recherche scientifique/French National Centre for Scientific Research