Upon repeated testing, the LiFNFSI electrolyte material displayed an ability to improve the performance of batteries operating at high temperatures. In an automotive application, this high-temp resiliency could prove beneficial, allowing automakers to forego the expensive liquid cooling techniques currently used to control battery temps in some plug-in vehicles.The electrolyte having 1.0 M LiFNFSI in a mixture of ethylene carbonate and ethyl methyl carbonate shows high conductivity comparable to LiClO4, good electrochemical stability, and does not corrode aluminum. At both room temperature (25 °Celsisus) and elevated temperature (60 °C), the graphite/LiCoO2 cells with LiFNFSI exhibit better cycling performances than those with LiPF6.
Particularly, at 60 °C, the capacity fading rate of the LiFNFSI-based cell without any additive is 37% after 100 cycles, while the cell with LiPF6 fails rapidly. These outstanding properties of LiFNFSI make it an attractive candidate to overcome the rapid capacity fading of lithium-ion batteries at elevated temperatures.
[Source: Green Car Congress]