"The need for materials with improved electrochemical energy storage properties has become increasingly critical as society grapples with limited fossil fuel reserves and the threat of climate change. Lithium-ion batteries and supercapacitors are related energy storage systems that store energy electrochemically. Recently, researchers have shown that amorphous structures, defects, non-stoichiometric domains, interfaces between components, and surface modifications may play critical roles in their energy storage properties. However, such systems are difficult to characterize at a molecular level because such structural features lack long-range molecular order and are characterized by broad distributions. The objective of this project is to measure, understand, and control how specific molecular-level properties of complex, heterogeneous materials for lithium-ion batteries and supercapacitors affect their energy storage capabilities, charging/discharging rates, ion transport properties, chemical/structural stabilities, and cycle lifetimes. Molecular compositions, structures, interactions, and dynamics of the charge carriers and electrodes will be established by multi-dimensional, pulsed-field gradient, and in situ solid-state nuclear magnetic resonance (NMR) spectroscopy. Molecular insights from NMR will be correlated with macroscopic material, electrochemical, and device properties, yielding new understanding of their molecular origins. The results are expected to aid the rational design of novel lithium-ion batteries and supercapacitors with greater energy densities, power densities, and operational lifetimes. This project will strengthen the European Research Area’s excellence and competitiveness in materials for electrochemical energy storage. It will provide European scientists with powerful diagnostic tools to better understand the molecular origins of electrochemical energy storage properties in state-of-the-art electrode and electrolyte systems."