Novel material discoveries and the optimization of next-generation technologies rely on modeling and simulation. The accuracy and success of models and simulations rely on a foundation of accurate thermodynamic properties. This presentation focuses on metrology advances in measuring the thermodynamic property of sound speed for liquid phase materials. Compared to other thermodynamic properties the speed of sound can be measured automatically and more rapidly across wide ranges of temperature and pressure with low uncertainty. First, we present a custom instrument that can measure the sound speed of liquids across temperatures of 230 – 420 K, and pressures up to 90 MPa with a measurement uncertainty of 0.04%. Using this instrument, we present new data on two materials frequently used in next-generation energy technologies: Difluoromethane (DFM or HCF-32, CH2F2) and N, N-Dimethylformamide (DMF, (CH3)2NCH). Difluoromethane is historically used as a refrigerant, but recently it has been applied as a liquified-gas electrolyte in lithium-ion batteries that would be safer and have a wider operating temperature range compared to current electrolytes. Difluoromethane was measured over the range of 230 and 345 K, with pressures from 2.1 to 70 MPa. N, N-Dimethylformamide is a common organic solvent used in a multitude of material synthesis procedures and has been used as an electrolyte additive in lithium-ion batteries. N, N-Dimethylformamide was measured over the range of 230 and 420 K, with pressures from 0.1 to 70 MPa. The instrument and data presented to improve the first principle understanding of battery materials by accurately defining thermodynamic data needed for accurate data-driven modeling and simulations.

Advances in sound-speed metrology for thermodynamic data on difluoromethane and N,N- dimethylformamide to enable modeling and simulation of next-generation technologies

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.