A circular economy in the built environment via carbon mineralization of alkaline industrial wastes and silicate minerals via P_CO2 swing or via pH swing, employing acid and base generated from electrolysis using renewable energy.

Solid Electrolyte Interphase (SEI) has been identified as the most important and least understood component in lithium-ion batteries. Despite extensive studies in the past two decades, a few mysteries remain: what is the chemical form of and degree of mobility of Li⁺ in the interphase? What fraction of Li⁺ is permanently immobilized in the SEI, while the rest are still able to participate in the cell reactions via the ion-exchange process with Li⁺ in the electrolyte? This study attempted to answer, in part, these questions by using ⁶Li and ⁷Li-isotopes to label SEIs and electrolytes, and then quantifying the distribution of permanently immobilized and ion-exchangeable Li⁺ with solid-state NMR and ToF-SIMS. The results showed that the majority of Li⁺ were exchanged after one SEI formation cycle, and a complete exchange after 25 cycles. Ion exchange by diffusion based on concentration gradient in the absence of applied potential also occurred simultaneously. This knowledge will provide a foundation for not only understanding but also designing better SEIs for future battery chemistries.

Fluorine-containing anions are widely used in ionic liquids due to their unique physicochemical properties. However, the local dynamics of both cations and anions and their associated relaxation mechanisms remain incompletely understood. Here, we present a ¹H and ¹⁹F spin-lattice relaxation rate (R₁) study as a function of frequency over a broad frequency range from 30 kHz to 800 MHz for ionic liquids containing BF₄^-, PF₆^-, TFSI^-, and FSI^- anions and EMIM⁺ cation. By combining experimental R₁^H and R₁^F NMR dispersion (NMRD) profiles with relaxation models for both dipolar spin interactions and chemical shift anisotropy (CSA) contributions, we demonstrate that CSA is needed to accurately describe the R₁^F relaxation behavior above ∼300 MHz, the extent of which depends on the anion structure. These findings challenge the long-standing assumption that dipolar contribution is the main source of ¹⁹F relaxation in these systems and highlight the importance of including CSA to accurately interpret ¹⁹F relaxation in ionic liquids, particularly at high frequencies. This work provides new insights into the molecular dynamics of fluorine-containing species.

Deep Eutectic Solvents (DESs) have emerged as promising candidates to replace conventional organic solvents in various technological applications due to their low vapor pressure, non-flammability, and ease of preparation at low costs. In particular, Type IV DESs, which are composed of metal salts and hydrogen bond donors, are possible replacements for lithium-ion battery electrolytes. In this study, we investigate the molecular dynamics of solvents of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and pyrazole (PYR) at varying LiTFSI:PYR molar ratios (1:2, 1:3, 1:4, 1:5) using Nuclear Magnetic Resonance Dispersion (NMRD) and Pulsed Field Gradient (PFG) Nuclear Magnetic Resonance (NMR). PFG NMR reveals composition-dependent diffusion trends, while NMRD provides molecular-level insights into the longitudinal relaxation rate (R₁ = 1/T₁). Notably, the LiTFSI:PYR (1:2) sample shows distinct behavior across both techniques, exhibiting enhanced relaxation rates and lower self-diffusion for ¹H compared to the other nuclei (¹⁹F and ⁷Li), suggestive of stronger and more efficient Li⁺–pyrazole interactions, as confirmed by the modeling of the relaxation profiles. Our study advances understanding of ion dynamics in azole-based eutectic solvents, supporting their potential use in safer battery electrolytes.

Ionogel electrolytes incorporating exfoliated hexagonal boron nitride (hBN) nanoplatelets are promising materials for next-generation energy storage systems. However, detailed understanding of their ion transport properties at the molecular level remains limited. This study employs diffusion and relaxation nuclear magnetic resonance (NMR) techniques, including fast-field cycling (FFC) NMR, to investigate the dynamics of ionic species in hBN-ionogels. By spanning a broad frequency range from 30 kHz using FFC NMR to high-field NMR (500–800 MHz), we reveal distinct relaxation mechanisms governing ion dynamics in ionogels with and without lithium salts. Our results highlight the role of hBN in modulating molecular rotation and translational motion, significantly affecting 1H and 19F relaxation profiles. The presence of Li+ alters the dynamic behavior in ionogels, enhancing anion mobility at the interface. Notably, 7Li relaxation reveals strong interactions with the hBN surface that cannot be detected by diffusion NMR. These findings underscore the importance of spanning a broad frequency range in NMR studies of ionogels and provide critical insights into optimizing their design as novel electrolytes.