International Associated Laboratory: IONOMER MATERIALS FOR ENERGY (LIME)



Principal Investigators
Maria Luisa Di Vona
Philippe Knauth
Current Collaborators
Roberto Montanari
Maria Richetta
Alessandra Varone
Thierry Djenizian
Florence Vacandio
PhD students
Michele Braglia
Ivan Vito Ferrari
Previous Collaborators
Pr. Hongying Hou
Dr. Jedeok Kim
Dr. Debora Marani
Dr. Emanuela Sgreccia
Dr. Riccardo Narducci
Dr. Luca Pasquini
​Dr. M. Tamilvanan



The objective of the International Associated Laboratory “LIME” is to prepare and characterize ionomer materials for electrochemical energy technologies. Aromatic polymers are very attractive given their easy functionalization, low cost and easy recycling. Among the many aromatic polymers, we focus mainly on Poly(ether-ether-ketone) (PEEK), Poly(phenyl-sulfone) (PPSU), Polysulfone (PSU), and Poly(ether-sulfone) (PES).


1.  Proton conducting ionomers

Proton conducting ionomers are materials of choice for fuel cells and water electrolysis. The properties can be improved by innovative thermal treatments for annealing and cross-linking  (XL-SPEEK) the macromolecules.

2.  Cation conducting ionomers 

Various cations can be introduced by ion exchange or chemical reaction (e.g. with butyl-Li). The ionomers can be used as separators for rechargeable batteries (in anhydrous state) or for aqueous metal batteries.

3.  Hydroxide conducting ionomers

The most common ionomers contain quaternary ammonium groups. The basic operating conditions allow using non-noble electrocatalysts for the oxygen reduction reaction and thus an important cost reduction for alkaline fuel cells and water electrolysers.

4.  Anion conducting ionomers

They can be prepared by ion exchange from hydroxide conducting ionomers or by innovative synthesis by reaction of acids with basic groups (e.g. sulfonamides). Such ionomers are especially useful for redox flow batteries, where cation permeability must be minimized.

5.  Amphoteric ionomers

Acidic and basic groups coexist in a single macromolecule: the type and value of the ionic conductivity depends on the pH of its environment. This versatility and the low ionic permeability are very useful for technologies requiring low ion permeability.


Ionomer separators for electrochemical energy technologies are produced from the microscale (microbatteries based on TiO2 nanotubes) to the macroscale (redox flow batteries). The characterization techniques include spectroscopies (FTIR, UV and NMR), thermogravimetry, mechanical tests, permeability measurements, impedance spectroscopy and electrochemical measurements, such as cyclovoltammetry and galvanostatic polarization.


Partner Institutions
1 - Aix Marseille Université
2 - Università di Roma Tor Vergata
3 - Centre National de la Recherche Scientifique