January 2019 - In the pursuit of ever more energy-dense and longer lasting Li-ion batteries, the electrolyte is still an area of intense research. A good choice of electrolyte can make or break the long-term performance of a cell. This paper highlights various advances in electrolyte development and evaluation that have been made in the last several years. Blends of electrolyte additives that give superior capacity retention over several thousand cycles, as well as new formulations of electrolyte solvents to achieve higher charging rates and higher voltage operation are presented. The Advanced Electrolyte Model, a theoretical model for the calculation of electrolyte properties, is presented as an effective way to determine the transport properties of a diverse array of electrolyte systems thus speeding electrolyte development.