Study of lithium transport mechanisms at interfaces in organic/inorganic hybrid electrolytes

Lithium ion batteries are today the most realistic solution to answer the ever-increasing demand for electrochemical energy storage devices. The two main requirements for such systems are a higher gravimetric capacity and an increased safety, both can be solved using a solid electrolyte instead of the liquid ones in the current technology. At present time three main groups of solid electrolytes exist: polymers, inorganic materials, and hybrid materials (a mixture of an inorganic and an organic phase). Hybrids are especially promising as they combine the high ionic conductivity of inorganic electrolytes as well as the mechanical properties and easy processing of polymers.
The research on hybrid electrolytes has uncovered an important challenge: the organic-inorganic interface. In some cases, these interfaces can greatly decrease ionic conductivity and thus hinder battery performance. Little is still known about these interfaces, whether it’s their chemical (composition, structure) or electrochemical properties (conductivity, transference number). Mastering these interfaces is critical to ensure the development of competitive hybrid electrolytes and for their processing.
This PhD project will focus on understanding the ion transfer mechanisms at the polymer-inorganic interface in hybrid electrolytes. First the nature of the interface will be determined through chemical analyses, and its electrochemical properties will be measured on simple setups (electrochemical impedance spectroscopy, electron microscopy, NMR). From this, characterization methods will be proposed and applied to more realistic hybrid materials, dispersed inorganic particles in a polymer matrix for example, such materials will also be developed during this PhD. Those methods will then be used to investigate the influence of processing conditions on the polymer-inorganic interface. 

Keywords: lithium ion batteries, hybrid materials, interfaces, solid state electrolytes

Academic supervisor    Dr, ALLOIN Fannie, laboratoire d’électrochimie et physicochimie des matériaux et des interfaces
Doctoral School    I-MEP2 (N° 510), https://www.adum.fr/as/ed/page.pl?site=edimep2&page=accueil
IFPEN supervisor    Dr, HALTTUNEN Niki, Département électrochimie et matériaux, niki.halttunen@ifpen.fr,
PhD location    IFPEN, Lyon, France  and LEPMI, Grenoble, France
Duration and start date    3 years, starting in fourth quarter 2022
Employer    IFPEN, Lyon, France
Academic requirements    University Master degree material chemistry or electrochemistry
Language requirements    Fluency in French or English, willingness to learn French