Lithium-ion batteries (LIBs) are now used in the variety of fields including vehicles, and industrial and portable uses. Since the current LIBs use volatile and flammable electrolyte liquid, they have a risk on safety, e.g. explosion owing to an unexpected short. For ensuring the LIB safety, the cooling and safety mechanisms need to be installed in battery packs used for large scale applications, i.e. electric vehicles (EVs), and they compromise battery energy density and cost competitiveness.

To overcome the issue related to the LIB safety, we recently developed a novel electrolyte having the lower vapor pressure than the conventional organic liquid electrolyte, and incorporated it into LIB. High energy density of over 300 Wh/kg and high output power of over 1,600 W/kg were successfully demonstrated.

In the presention, the concept of our less volatile electrolyte, and evaluated results on performance of our highly safe, high energy density and high power LIB will be reported.

This work was supported by Innovative Science and Technology Initiative for Security, ATLA, Japan.