Stable polymers of up to 80 wt% elemental sulfur are formed from low cost industrial by-products, and renewable crosslinkers.

Composite solid-state electrolytes based on ball-milled LiBH4/SiO2 aerogel exhibit high lithium conductivities and we have found an optimal weight ratio, 30/70 wt% LiBH4/SiO2, with a conductivity of 0.1 mS/cm-1 at room temperature. We have studied the Li + and BH4dynamics using Quasi-Elastic Neutron Scattering and solid-state Nuclear Magnetic Resonance and found that only a small fraction (~10%) of the ions have high mobilities while most of the LiBH4 shows behavior similar to macrocrystalline material. The modified LiBH4 is formed from interaction with the SiO2 surface and most probably from reaction with the surface silanol groups. We successfully applied these composite electrolytes in lithium-sulfur solid-state batteries. The batteries show reasonable capacity retention (794 mAhg-1 sulfur after 10 discharge-charge cycles, coulombic efficiency of 88.8% ± 2.7% and average capacity loss of 7.2% during the first 10 cycles).

NMR spectroscopy has recently emerged as a powerful method for studying electrolyte species in microporous carbon electrodes used in capacitive energy storage devices. Key to this approach is the nucleus-independent chemical shift (NICS) which enables adsorbed species to be distinguished from those in the bulk electrolyte. The magnitude of the NICS is well known to be dependent on the distance of the adsorbed species from the carbon surface, and has therefore been used in several studies as a probe of the carbon pore size. However, the NICS can also be influenced by a number of other structural and chemical factors which are not always taken into account. To investigate this, we have carried out a systematic study of the factors influencing the NICS of aqueous electrolyte species adsorbed on polymer-derived activated carbon in the absence of an applied potential. We find that a number of effects arising from both the carbon structure as well as the behaviour and chemical properties of the electrolyte species can contribute to the observed NICS and must be taken into account when interpreting NMR spectra of microporous carbon electrode materials. In turn, the measurement of these effects provides important information about ion behaviour and reveals significant differences in the adsorption behaviour of different ions in the absence of an applied potential. In accordance with several computational studies, we find experimental evidence that the local concentration of spontaneously adsorbed alkali ions decreases with the pore size. This has potential implications for understanding the molecular-level mechanism of charge storage in capacitive devices.

The conjugation of a bithiophene was reversibly modulated over several cycles through the isomerization of an azobenzene.

The adsorption and diffusion of species in activated carbons is fundamental to many processes in catalysis and energy storage. Nuclear magnetic resonance (NMR) gives an insight into the molecular-level mechanisms of these phenomena thanks to the unique magnetic shielding properties of the porous carbon structure, which allows adsorbed (in-pore) species to be distinguished from those in the bulk (ex-pore). In this work we investigate exchange dynamics between ex-pore and in-pore solvent species in microporous carbons using a combination of one-dimensional (1D) and two-dimensional (2D) NMR experiments. We systematically compare the effects of four variables: particle size, porosity, solvent polarity and solvent viscosity to build up a picture of how these factors influence the exchange kinetics. We show that exchange rates are greater in smaller and more highly activated carbon particles, which is expected due to the shorter in-pore‐ex-pore path length and faster diffusion in large pores. Our results also show that in-pore‐ex-pore exchange of apolar solvents is slower than water, suggesting that the hydrophobic chemistry of the carbon surface plays a role in the diffusion kinetics, and that increased viscosity also reduces the exchange kinetics. Our results also suggest the importance of other parameters, such as molecular diameter and solvent packing in micropores.