Organic ionic plastic crystals having colossal barocaloric effects for sustainable refrigeration.

Barocaloric (BC) materials offer the potential for highly energy-efficient refrigeration by generating heat absorption through the effect of pressure on a solid-solid phase transition. However, very few of the known materials have the required phase transition in the temperature regions necessary for domestic refrigeration or air conditioning. We introduce organic ionic plastic crystals (OIPCs) as a new family of BC materials.

Trimodal thermal energy storage material for renewable energy applications.

The global aim to move away from fossil fuels requires efficient, inexpensive and sustainable energy storage to fully use renewable energy sources. Thermal energy storage materials in combination with a Carnot battery could revolutionize the energy storage sector. However, a lack of stable, inexpensive and energy-dense thermal energy storage materials impedes the advancement of this technology.

A case study using spectroscopy and computational modelling for Co speciation in a deep eutectic solvent.

Cobalt has a vital role in the manufacturing of reliable and sustainable clean energy technologies. However, the forecasted supply deficit for cobalt is likely to reach values of 150 kT by 2030. Therefore, it is paramount to consider end-of-life devices as secondary resources for cobalt.

Unexpected Energy Applications of Ionic Liquids.

Ionic liquids and their various analogues are without doubt the scientific sensation of the last few decades, paving the way to a more sustainable society. Their versatile suite of properties, originating from an almost inconceivably large number of possible cation and anion combinations, allows tuning of the structure to serve a desired purpose. Ionic liquids hence offer a myriad of useful applications from solvents to catalysts, through to lubricants, gas absorbers, and azeotrope breakers.

Insights into the Carbon Dioxide Separation Performance of Bis(trifluoromethylsulfonyl)imide-based Plastic Crystal Composite Membranes with Fluorinated Polar Polymers.

Membrane-based gas separation technologies are one solution towards mitigating global emissions of CO. New membrane materials with improved separation performance are still highly sought after. Composite membranes based on organic ionic plastic crystals (OIPCs) have shown preferential interaction for CO over N, leading in some cases to competitive CO/N selectivities.

Enhanced Dissolution of Metal Oxides in Hydroxylated Solvents - Towards Application in Lithium-Ion Battery Leaching.

The recovery of critical metals from spent lithium-ion batteries (LIBs) is rapidly growing. Current methods are energy-intensive and hazardous, while alternative solvent-based strategies require more studies on their 'green' character, metal dissolution mechanism and industrial applicability. Herein, we bridged this gap by studying the effect of dilute HCl solutions in hydroxylated solvents to dissolve Co, Ni and Mn oxides.

New organic ionic plastic crystals utilizing the morpholinium cation.

Organic ionic plastic crystals (OIPCs) are emerging candidates as safer, quasi solid-state ion conductors for various applications, especially for next-generation batteries. However, a fundamental understanding of these OIPC materials is required, particularly concerning how the choice of cation and anion can affect the electrolyte properties. Here, we report the synthesis and characterisation of a range of new morpholinium-based OIPCs and demonstrate the benefit of the ether functional group in the cation ring.

Development of New Plastic-Crystal Based Electrolytes using Pyrrolidinium- Bis(fluorosulfonyl)imide Dicationic Salts.

Dicationic organic salts are an interesting class of solid-state electrolyte materials due to their unique structure. Here we present, for the first time, the synthesis and characterization of three dicationic-FSI salts, 1,2-bis(N-methylpyrrolidinium)ethane bi(bis(fluorosulfonyl)imide) ([C -Pyrr1][FSI] ), 1,2-bis(N-ethylpyrrolidinium)ethane bi(bis(fluorosulfonyl)imide) ([C -Pyrr2][FSI] ) and 1,2-bis(N-n-propylpyrrolidinium)ethane bi(bis(fluorosulfonyl)imide) ([C -Pyrr3][FSI] ). The structure and dynamics of the organic salts were probed using variable temperature solid-state NMR and were compared with the thermal and transport properties.

Phase Change Materials for Renewable Energy Storage at Intermediate Temperatures.

Thermal energy storage technologies utilizing phase change materials (PCMs) that melt in the intermediate temperature range, between 100 and 220 °C, have the potential to mitigate the intermittency issues of wind and solar energy. This technology can take thermal or electrical energy from renewable sources and store it in the form of heat. This is of particular utility when the end use of the energy is also as heat.

Probing the molecular interactions and physicochemical properties of a cobalt-based redox electrolyte system for thermo-electrochemical cells.

Redox-active materials play a primary role in the high-performance electrochemical device research field. Their bulk ion dynamics and performances can be studied using different electrochemical analysis methods, but their molecular level interactions and dynamics on which these depend are often not well understood. Here, nuclear magnetic resonance (NMR) relaxation and double-stimulated echo pulsed field gradient (PFG) techniques have been used to gain insights into the molecular level interactions, exchange dynamics and self-diffusivity of the various species present in a cobalt-based redox active electrolyte system used for thermo-electrochemical applications, including how these factors depend on the oxidation state and concentration of the redox species.

Exploration of phase diagram, structural and dynamic behavior of [HMG][FSI] mixtures with NaFSI across an extended composition range.

Hexamethylguanidinium bis(fluorosulfonyl)imide ([HMG][FSI]) has recently been shown to be a promising solid state organic ionic plastic crystal with potential application in advanced alkali metal batteries. This study provides a detailed exploration of the structural and dynamic behavior of [HMG][FSI] mixtures with the sodium salt NaFSI across the whole composition range from 0 to 100 mol%. All mixtures are solids at room temperature.

Predicting gas selectivity in organic ionic plastic crystals by free energy calculations.

Organic ionic plastic crystals (OIPCs) are molecularly disordered solids, and their potential for the development of gas separation membranes has recently been demonstrated. Here, the gas absorption capability of the OIPC, diethyl(methyl)(isobutyl)phosphonium hexafluorophosphate ([P][PF]), for four gases is predicted through potential of mean force (PMF) calculations based on two methods - average force method and adaptive biasing force method. Both methods correctly predicted the different trends of adsorption and absorption of these gases across the OIPC-gas interface.

Halide-Free Synthesis of New Difluoro(oxalato)borate [DFOB] -Based Ionic Liquids and Organic Ionic Plastic Crystals.

The implementation of next-generation batteries requires the development of safe, compatible electrolytes that are stable and do not cause safety problems. The difluoro(oxalato)borate ([DFOB] ) anion has been used as an electrolyte additive to aid with stability, but such an approach has most commonly been carried out using flammable solvent electrolytes. As an alternative approach, utilisation of the [DFOB] anion to make ionic liquids (ILs) or Organic Ionic Plastic Crystals (OIPCs) allows the advantageous properties of ILs or OIPCs, such as higher thermal stability and non-volatility, combined with the benefits of the [DFOB] anion.

Plastic crystal-based electrolytes using novel dicationic salts.

The unique structures of dications increase the number of possible combinations of cations and anions that can be used to obtain new materials with a wide range of physicochemical properties. However, structure-property relationships related to dicationic organic salts are seldom explored. Here, we report the synthesis and characterization of two new dicationic salts, 1,2-bis(-ethylpyrrolidinium)ethane bis(trifluoromethanesulfonyl)imide ([C-Pyrr2][TFSI]) and 1,2-bis(-propylpyrrolidinium)ethane bis(trifluoromethanesulfonyl)imide ([C-Pyrr3][TFSI]).

Zwitterionic materials with disorder and plasticity and their application as non-volatile solid or liquid electrolytes.

Zwitterionic materials can exhibit unique characteristics and are highly tunable by variation to the covalently bound cationic and anionic moieties. Despite the breadth of properties and potential uses reported to date, for electrolyte applications they have thus far primarily been used as additives or for making polymer gels. However, zwitterions offer intriguing promise as electrolyte matrix materials that are non-volatile and charged but non-migrating.

Operando magnetic resonance imaging for mapping of temperature and redox species in thermo-electrochemical cells.

Low-grade waste heat is an abundant and underutilised energy source. In this context, thermo-electrochemical cells (i.e.

Strategies for Integrated Capture and Conversion of CO from Dilute Flue Gases and the Atmosphere.

The integrated capture and conversion of CO has the potential to make valorization of the greenhouse gas more economically competitive, by eliminating energy-intensive regeneration processes. However, integration is hindered by the extremely low concentrations of CO present in the atmosphere (0.04 vol.

Organic Ionic Plastic Crystal-Based Composite Membranes for Light Gas Separation: The Impact of Varying Ion Type and Casting Method.

The promise of organic ionic plastic crystals (OIPCs) for development of a novel type of gas separation membrane with competitive gas selectivity for CO /N was recently demonstrated. This work aimed to design more selective membranes by investigating a different type of OIPC and a new membrane preparation method. Two different OIPCs were solvent-cast or co-cast with poly(vinylidene difluoride) (PVDF), and their gas transport properties were compared.

The influence of alkyl chain branching on the properties of pyrrolidinium-based ionic electrolytes.

Ionic liquids and plastic crystals based on pyrrolidinium cations are recognised for their advantageous properties such as high conductivity, low viscosity, and good electrochemical and thermal stability. The pyrrolidinium ring can be substituted with symmetric or asymmetric alkyl chain substituents to form a range of ionic liquids or plastic crystals depending on the anion. However, reports into the use of branched alkyl chains and how this influences the material properties are limited.

Toward High-Energy-Density Lithium Metal Batteries: Opportunities and Challenges for Solid Organic Electrolytes.

With increasing demands for safe, high capacity energy storage to support personal electronics, newer devices such as unmanned aerial vehicles, as well as the commercialization of electric vehicles, current energy storage technologies are facing increased challenges. Although alternative batteries have been intensively investigated, lithium (Li) batteries are still recognized as the preferred energy storage solution for the consumer electronics markets and next generation automobiles. However, the commercialized Li batteries still have disadvantages, such as low capacities, potential safety issues, and unfavorable cycling life.

Unique Layer-Doping-Induced Regulation of Charge Behavior in Metal-Free Carbon Nitride Photoanodes for Enhanced Performance.

Photoinduced charge carrier behavior is critical in determining photoelectrocatalytic activity. In this study, a unique layer-doped metal-free polymeric carbon nitride (C N ) photoanode is fabricated by using one-pot thermal vapor deposition. With this method, a photoanode consisting of a phosphorus-doped top layer, boron-doped middle layer, and pristine C N bottom layer, was formed as a result of the difference in thermal polymerization kinetics associated with the boron-containing H BO -melamine complex and the phosphorus-containing H PO -dicyandiamide complex.

Organic salts utilising the hexamethylguanidinium cation: the influence of the anion on the structural, physical and thermal properties.

The synthesis and characterisation of new solid-state electrolytes is a key step in advancing the development of safer and more reliable electrochemical energy storage technologies. Organic ionic plastic crystals (OIPCs) are an increasingly promising class of material for application in devices such as lithium or sodium metal batteries as they can support high ionic conductivity, with good electrochemical and thermal stability. However, the choice of OIPC-forming ions is still relatively limited.

Water-Facilitated Electrodeposition of Neodymium in a Phosphonium-Based Ionic Liquid.

Rare-earth metals are considered critical metals due to their extensive use in energy-related applications such as wind turbines and nickel-metal hybrid batteries found in hybrid electrical vehicles. A key drawback of the current processing methods includes the generation of large amounts of toxic and radioactive waste. Thus the efficient recovery of these valuable metals as well as cleaner processing methods are becoming increasingly important.

Efficient and Stable Solid-State Dye-Sensitized Solar Cells by the Combination of Phosphonium Organic Ionic Plastic Crystals with Silica.

Remarkably efficient quasi-solid-state dye-sensitized solar cells (DSSCs) have been fabricated using organic ionic plastic crystal electrolytes based on a small triethyl(methyl)phosphonium [P] cation and two types of sulfonamide anions, bis(fluorosulfonyl)amide (FSA) and bis(trifluoromethanesulfonyl)amide (TFSA), in combination with varying amounts of silica (SiO). Solar cell efficiencies of up to 7.4% were obtained, which is comparable to our benchmark efficiencies of liquid (acetonitrile) electrolyte-based devices.