# Effect of Ionic Liquids on the Structure of Ionomer Inks

## TL;DR

This study shows how ionic liquids affect the structure of inks used in fuel cells, impacting their performance.

## Contribution

The novel contribution is identifying how specific ionic liquids alter ionomer-catalyst interactions in fuel cell inks.

## Key findings

- Ionic liquid composition affects ionomer arrangement and interactions in catalyst inks.
- The [BMIM][C4] ionic liquid reduces platinum site availability and PEMFC performance.
- These structural insights can guide better ionic liquid formulations for fuel cells.

## Abstract

This study investigates
the impact of ionic liquids (ILs)
on the
structure and performance of catalyst inks used in proton exchange
membrane fuel cells (PEMFCs). Using contrast variation small-angle
neutron scattering (CV-SANS), we elucidate the structural interactions
between ionomers, Pt/C catalyst particles, and ILs. The analysis reveals
that IL composition significantly influences the arrangement of ionomers
and their interactions with other ink components. In particular, one
of the ILs ([BMIM]­[C4]) exhibited stronger associations with both
ionomer and catalyst particles, resulting in reduced availability
of platinum catalytic sites and lower PEMFC performance. These findings
demonstrate the structural origins of electrochemical performance
variations, providing insights into the design of improved ionic liquid
formulations for enhanced fuel cell efficiency.