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Abstract Electrical double‐layer supercapacitors offer numerous advantages in the context of energy storage; however, their widespread use is hindered by the high unit energy cost and low specific energy. Recently, water‐in‐salt (WIS) electrolytes have garnered interest for use in energy storage devices. Nevertheless, their direct application in high‐power devices is limited due to their high viscosity. In this study, we investigate the WIS Lithium bis(trifluoromethanesulfonyl)Imide (LiTFSI) electrolyte, revealing a high specific capacitance despite its elevated viscosity and restricted ionic conductivity. Our approach involves nuclear magnetic resonance (NMR) analysis alongside electrochemical analyses, highlighting the pronounced advantage of the WIS LiTFSI electrolyte over the WIS LiCl electrolyte at the molecular level. The NMR analysis shows that the LiTFSI electrolyte ions preferentially reside within the activated carbon pore network in the absence of an applied potential, in contrast to LiCl where the ions are more evenly distributed between the in‐pore and ex‐pore environments. This difference may contribute to the difference in capacitance between the two electrolytes observed during electrochemical cycling.

Borates offer extended structural diversity and promise in diverse applications. Here the authors report a borate with linear BO2 units as well as NMR spectroscopy characterization that provides a quantitative basis for identification of BO2 units in polycrystalline and non-crystalline samples.

Transitioning to electrified transport requires improvements in sustainability, energy density, power density, lifetime, and approved the cost of lithium-ion batteries, with significant opportunities remaining in the development of next-generation cathodes. This presents a highly complex, multiparameter optimization challenge, where developments in cathode chemical design and discovery, theoretical and experimental understanding, structural and morphological control, synthetic approaches, and cost reduction strategies can deliver performance enhancements required in the near- and longer-term. This multifaceted challenge requires an interdisciplinary approach to solve, which has seen the establishment of numerous academic and industrial consortia around the world to focus on cathode development. One such example is the Next Generation Lithium-ion Cathode Materials project, FutureCat, established by the UK’s Faraday Institution for electrochemical energy storage research in 2019, aimed at developing our understanding of existing and newly discovered cathode chemistries. Here, we present our perspective on persistent fundamental challenges, including protective coatings and additives to extend lifetime and improve interfacial ion transport, the design of existing and the discovery of new cathode materials where cation and cation-plus-anion redox-activity can be exploited to increase energy density, the application of earth-abundant elements that could ultimately reduce costs, and the delivery of new electrode topologies resistant to fracture which can extend battery lifetime.

Inverse vulcanization allows stable polymers to be made from elemental sulfur, but development is restricted by cross-linkers and the elevated temperatures required. Here the authors report a catalytic method for a wide range of cross-linkers and found a reduced reaction temperature and reaction time is required.

2hJNN hydrogen-bond mediated J couplings are measured in the solid state for two synthetic deoxyguanosine derivatives by 15N MAS NMR spin-echo experiments. The use of rotor-synchronised Hahn-echo pulse train (RS-HEPT) 1H decoupling, with a duty cycle of 6%, allows spin-echo durations out to 200 ms, hence enabling the accurate determination of J couplings as small as 3.8 Hz. A single-crystal X-ray diffraction structure exists for the shorter alkyl chain derivative dG(C3)2: the observation of significantly different 2hJNN couplings, 6.2 ± 0.4 and 7.4 ± 0.4 Hz, for the two resolved N7 resonances is to be expected given the NH⋯N hydrogen-bonding distances of 2.91 and 2.83 Å for the two distinct molecules in the asymmetric unit cell. For the longer alkyl chain derivative, dG(C10)2, for which there is no single-crystal diffraction structure, a 15N refocused INADEQUATE spectrum (Pham et al., J. Am. Chem. Soc., 2005, 127, 16018–16019) has demonstrated the presence of N2–H⋯N7 intermolecular hydrogen-bonds indicative of a quartet-like structure. The 2hJNN hydrogen-bond mediated J coupling of 5.9 ± 0.2 Hz is at the lower end of the range (5.9–8.2 Hz) of 2hJNN couplings determined from solution-state NMR of guanosine quartets in quadruplex DNA. A full discussion of the determination of error bars on the fitted parameters is given; specifically, error bars determined by a non-linear fitting (using the covariance matrix) or in a Monte-Carlo fashion are found to give effectively identical results. [ABSTRACT FROM AUTHOR]