Ionic liquids confined in 1D CNT membranes:gigantic ionic conductivity

TL;DR

This paper demonstrates that confining ionic liquids within one-dimensional carbon nanotube membranes significantly enhances their ionic conductivity, making them promising for high-power energy storage applications.

Contribution

It reveals how 1D CNT confinement boosts ionic conductivity of ILs by over an order of magnitude, a novel approach for improving electrolyte performance.

Findings

Ionic conductivity increases by more than tenfold in 1D CNT confinement.

1D CNT membranes act as effective separators for high-power batteries.

Self-organization of ILs is influenced by nanoscale confinement.

Abstract

Ionic Liquids (ILs) are organic molten salts characterized by the total absence of solvent. They show remarkable properties: low vapor pressure, high ionic conductivity, high chemical, thermal and electrochemical stability. These electrolytes meet therefore key criteria for the development of safe energy storage systems. Due to a competition between electrostatic and van der Walls interactions, ILs show an uncommon property for neat bulk liquids: they self-organize in transient nanometric domains. In ILs-based electrochemical devices, this fluctuating nano-segregation acts as energy barriers to the long range diffusional processes and hence to the ionic conductivity. Here, we show how the ionic conductivity of ILs can be increased by more than one order of magnitude by exploiting one dimensional (1D) confinement effects in macroscopically oriented carbon nanotube (CNT) membranes. We identify 1D CNT membranes as promising separators for high instant power batteries.