HOT-operando-NMR: A new versatile solid-state NMR probe system for high-temperature operando NMR studies of solid-state battery materials

Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful technique for investigating electrochemical processes in energy storage devices. Operando NMR measurements enable real-time analysis of electrochemical reactions in electrochemical cells such as batteries and supercapacitors. However, the study of next-generation solid-state batteries and high-temperature ionic liquid electrolytes presents considerable challenges due to the operating temperatures up to 300 °C. Conventional NMR equipment, which employs superconducting magnets inside helium-cooled environments (~ -270 °C), faces critical thermal limitations when incorporating high-temperature electrochemical cells. To overcome these challenges, a high-temperature operando NMR probe system (HOT-operando-NMR) has been developed to facilitate electrochemical studies at temperatures up to 300 °C. The HOT-operando-NMR system is modular and can be integrated and synchronized with any NMR system. Key innovations include: (1) high-temperature operation with precise temperature control and multiple temperature sensor monitoring capabilities, (2) effective thermal insulation to protect the magnet bore, and (3) implementation of high-temperature electrochemical cells with novel designs for investigating battery materials and electrochemical reactions. The system was designed by NMR Service GmbH and developed in collaboration with TU Dresden. This design incorporates advanced heat management, real-time temperature monitoring with ±1 °C accuracy, and automated optimization of measurement parameters. The envisioned commercialization of the HOT-operando-NMR approach is expected to provide both academic and industrial researchers with a robust method for advancing the study of next-generation energy storage systems.