Ionic Liquids as Cathode Additives for High Voltage Lithium Batteries
Journal article, 2024

Two oxalatoborate ionic liquids (ILs), which are commonly utilized as electrolyte additives that form a protective layer on the cathode surface, are investigated for the first time as electrode additives. Cathodes based on LiNi0.5Mn1.5O4 (LNMO) containing 3 wt % ILs, i. e., “IL-enriched cathodes”, exhibit capacity values above 120 mAh/g with high Coulombic efficiencies throughout cycling over 200 times. A cathode without ILs also exhibits a capacity of 119 mAh/g but its Coulombic efficiency becomes low and unstable after 109 cycles. In addition, when 0.3 M ILs are added to conventional carbonate-based electrolytes, the battery cycle life improves but there is a reduction in the capacity probably due to low ionic conductivity of the electrolyte mixtures. Post-mortem analyses of electrodes retrieved from cycled cells highlight less electrolyte decomposition and less cathode corrosion, enabled by using the IL as the additive in LNMO, which are confirmed by a particle shape with smooth surface identical to the fresh cathode. The study demonstrates that oxalatoborate ILs can be used as the electrode additive, and this provides a new concept for cathode formulations for high performance batteries with a small amount of ILs.

cathode additives

LNMO

ionic liquids

lithium

high-voltage cathodes

Author

Matteo Palluzzi

Sapienza University of Rome

Akiko Tsurumaki

Sapienza University of Rome

Nataliia Mozhzhukhina

Chalmers, Physics, Materials Physics

Josef Rizell

Chalmers, Physics, Materials Physics

Aleksandar Matic

Chalmers, Physics, Materials Physics

Paola D'Angelo

Sapienza University of Rome

M.A. Navarra

Sapienza University of Rome

Batteries and Supercaps

25666223 (eISSN)

Vol. 7 7 e202400068

Subject Categories

Energy Engineering

Materials Chemistry

Other Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1002/batt.202400068

More information

Latest update

7/20/2024