SALSA: A low-cost self-driving lab modular add-on for salt solubility assessment for battery electrolytes

Abstract

Solubility is the maximum amount of solutes that can dissolve in a certain amount of solvent at a certain temperature, and it is significant in battery electrolyte research since it confines the design space. Thus, solubility measurement is a critical constraint on running self-driving labs for battery electrolyte design. Herein, we introduce a low-cost experiment-execution and decision-making level Self-Driving Lab (SDL) modular add-on for automated solubility measurement of liquid electrolytes, enabling automated liquid dosing, powder dosing, weighing, stirring, temperature tracking, and dissolution recognition process via Python control, which plays a crucial role in accelerating electrolyte discovery and optimization. This solubility testing add-on module costs around 100 US dollar to build (in addition to the system previously built in our research group), gains good performance against benchmark data, and collects new solubility results of Sodium Bis(fluorosulfonyl)imide (NaFSI) salt in pure and mixed solvents of Acetonitrile (ACN), 1,2-dimethoxyethane (DME), and Ethyl Methyl Carbonate (EMC) under tracked room temperature of 25.4±0.2°C.