Collaboration |

Catalysis 🧪 2021-2023

Wed, 01 Dec 2021 00:00:00 +0000

🔍 Overview

This project was an academic collobaration initiated by D. Pla (CNRS researcher at LHFA, UMR5069, Toulouse). The aim was to demonstrate that Ni and Co nanoparticles deposited on substrates (for catalysis) were in a metalic state using XPS which was a challenge as such materials are highly reactive to O2 and H2O traces.

🎯 Key Finding / 👤 My Contributions

I developped a specific XPS sample preparation and analysis which allowed demonstrating the partially metallic state of the Ni or Co nanoparticles in agreement with their catalytic properties.

📢 Communication

📄 4 publications

RAISE 🪫 2019-2023

Tue, 01 Oct 2019 00:00:00 +0000

🔍 Overview

This project was an academic (IPREM and D-MEX) and industrial (Arkema and Saft) collaboration. It aimed at developing a polymer-based all-solid-state battery as well as developping inovatives methods to reveal the buried interfaces of the solid-state batteries in order to understand and optimize the aging mechanisms. It was built on a collaboration initiated with L. Rubatat (Polymerist at IPREM) including the Master thesis of F. Fall and also on the pionering results obtained in the . This project was funded by the E2S-UPPA I-SITE and led by H. Martinez.

🎯 Key Findings

Development of a unique non-destructive argon-ion beam cross-sectioning method for polymer-based all-solid-state batteries (-150°C).
Development of in situ XPS analysis using a dedicated electrochemical cell.
Development of new approaches for operando analysis using electron beams for Auger (world-first) and XPS.
Development of an in situ cycling cell for X-ray tomography.

👤 My Contributions

Writing (65%), WP leader (analytical development: cross-section, in situ, operando).
Co-supervision of 2 postdocs (I. Lopez-Marin and S. Patra).
Co-direction of 🎓 J. Morey’s PhD thesis (70%).
Download J. Morey PhD thesis - PDF (fr-en)

📢 Communication

📄 4 publications
🎤 2 international conferences

TROPIC 🔋 2019-2023

Tue, 01 Oct 2019 00:00:00 +0000

🔍 Overview

This project was an academic collaboration (ICGM, ICMCB and IPREM) that was built notably on the . It was funded by the French National Research Agency and led by L. Monconduit. The aim was to develop alternative K-ion batteries with >90 Wh/kg while (i) adressing the K metal reactivity, (ii) selecting the promising active materials and optimizing the corresponding electrodes formulation and (iii) assembling reliable and optimized full cells with a focus on the aging understanding.
Two PhD were funded, R. Wernert and B. Larhrib. The key findinds decrisbed after refer to B. Larhrib’s thesis entitled “From Electrode Design to K-Ion Full Cell Optimization: Electrochemical Performance and Interface Phenomena Investigations”.

🎯 Key Findings

Optimized graphite electrode formulation with…..btention of thick graphite electrodes (8 mg/cm² vs. 1–2 mg/cm² in the literature).
Full cells assemlby methodology …
First full graphite//KVPO4F cells with 50 Wh/kg energy density (device level).
aging….

👤 My Contributions

Writing (25%), WP leader (graphite electrode formulation, full-cells assembly, electrolyte formulation and aging mechanism using XPS).
Co-direction of 🎓 B. Larhrib’s PhD thesis (85%).
Download B. Larhrib PhD thesis - PDF (en)

📢 Communication

📄 7 publications
🎤 2 international conferences

K-ion Genesis 🔋2018-2021

Mon, 01 Jan 2018 00:00:00 +0000

🔍 Overview

This K-ion battery research project was initiated through a preliminary study, in collaboration with ICGM (L. Monconduit / L. Stievano) and LRCS (G. Gachot) within the RS2E network.
In parallel, a PhD funding was secure by L. Caracciolo via E2S-UPPA I-SITE, entitled: “Study of K-ion batteries: redox processes and interfacial phenomena”.

🎯 Key Findings

Preliminary study:

Detrimental interactions (cross-talks) between electrodes were highlighted. In other words, species formed on the K-metal surface migrate and deposit at the working electrode surface whatever the electrode/electrolyte combination was thus preventing SEI study in half-cells in K-ion batteries.

PhD results:

XPS was used on KVPO4FxO1-x and revealed a high reversibility of the redox processes although the K+ extraction (and insertion) from x = 0.5 to 0 was hindered, possibly by structural constraints while electrolyte degradation occurred mostly above 4.5V.
An unique XPS database was created with K-based SEI reference compounds compared to Li and Na ones.
XPS (SEIs) and GC/MS/FTIR (Gases) analysis were combined for the first time to determine the complete degradation pathways of KPF6 and KFSI in EC:DEC in contact with K-metal and compared to LiPF6 in EC:DEC in contact with Li metal.

👤 My Contributions

The XPS - GC/MS/FTIR combination that for the time allowed obtening full degradation mechanisms of electrolytes.
Co-direction of 🎓 L. Caracciolo’s PhD thesis (>75%).
Download L. Caracciolo PhD thesis - PDF (fr-en)

📢 Communication

📄 5 publications
🎤 3 international conferences

🚀 Next Steps

K-ion Genesis outcomes helped built the

Cross-section ✂️ 2017...

Sun, 01 Jan 2017 00:00:00 +0000

🔍 Overview

To investigate in depth morphology and chemical distribution of composite materials and electrodes, I developed cross-sectioning methods using Ar+ ions beam coupled to Auger analysis. It allows analyzing morphological and chemical informations of a micro-scale region of interest with a nano-scale resolution (~30 nm lateral, ~3 nm depth). This approach was applied to:

Composite electrodes based on conversion materials for batteries: conversion materials such as MSnSb (M=Ti or Nb) overcome huge volume expansion (>200%) and very fast amorphization so that conventional XRD/SAXS as well as TEM (focusing individual particles) are unsuitable tecnhiques to study their reversibility. This was performed in collaboration with L. Monconduit (ICGM).
Nano-composite powders for supercaps: MnO2-CoOOH performance being governed by their assembly, morphology and porosity at both the nano- and micro-scales, standard XRD (coherent domain size), SEM (surface) and TEM (individual particles) are unsuitable tecnhiques to fully asses their properties at once. It started as a preliminary collaboration with D. Giaume (Chimie ParisTech) and L. Guerlou-Demourgues (ICMCB) through the RS2E network. As the result were conclusive, this method was pursued in a larger project funded by the REGION Nouvelle-Aquitaine and led by D. Flahaut (IPREM).

🎯 Key Findings

Composite electrodes: The cross-section/Auger approach demonstrated for the first time that conversion of MSnSb (M=Ti or Nb) still occurs after 400 cycles. It occurs through a shell to core expansion/break up of the particles upon cycling. This leads to a micron scale spreading that fills the initially large and highly porous structure of the electrodes together with a large electrode volume expansion.
Composite powders: The cross-section/Auger approach revealed for the first the Mn-Co scale organization together with the morphology and porosity at both the micro-particles and nano scales.

👤 My Contributions

Development of both the electrodes / powders cross-sectioning and Auger analysis protocols with the support of J.-B. Ledeuil (CNRS Research Engineer, IPREM).
Co-supervision of 🎓 A. Lemoine’s PhD thesis (20%).
Download A. Lemoine PhD thesis - PDF (fr-en)

📢 Communication

📄 6 publications
🎤 2 international conferences

🚀 Next Steps

Cross-section were then applied to solid-state battery stacks in the