Articles in 2018

Efficient conversion of low-grade heat into useful power is a challenge. A new approach using magnetocaloric materials and a pretzel-like magnetic field topology offers a simple way of generating electrical power from heat with improved efficiency.

Multilateral development banks, such as the World Bank, have been encouraging countries to invest more in green-energy technologies. Analysis of project data suggests their own renewable energy portfolios have also grown in step.

Thermomagnetic generators exploit magnetic flux and temperature differences across magnetocaloric materials to generate electricity from waste heat. Waske et al. present a device based on a pretzel-like magnetic-field topology that leads to a higher power output than previous, simpler, topologies.

Separators are an essential part of current lithium-ion batteries. Vanessa Wood and co-workers review the properties of separators, discuss their relationship with battery performance and survey the techniques for characterizing separators.

Mounting calls for action on low-carbon heating and cooling systems are welcome, but we must move beyond only talking about it.

Integrating electrocatalytic H₂ production with biological H₂-fed systems for CO₂ upgrading requires H₂ generation to occur in biocompatible media—typically with neutral pH. Here, the authors design multi-site H₂ evolution catalysts that minimize the water dissociation barrier and promote hydride coupling in neutral media.

Electric aircraft offer an aviation decarbonization pathway and attract increasing attention owing to the rapid development of batteries. Here Andreas Schäfer and colleagues analyse the potential technological, economic and environmental viability of battery-electric commercial aircraft.

Perceptions of energy use and potential savings are rife with systematic and problematic errors. Now research shows that these misperceptions are more important predictors than actual savings for consumer acceptance of a demand-side response programme, potentially limiting the effectiveness of such programmes for both utilities and consumers.

Aluminium−graphite batteries can reversibly store AlCl₄^– ions at their cathodes, but the large consumption of electrolytes reduces their specific energy. Here a cathode based on redox-active triangular organic molecules is shown to be able to take up AlCl₂⁺, offering hope towards complete Al-ion storage.

Time-of-use tariffs aim to shift energy use to better match available supply. This study shows that perception of savings, more so than actual savings, predicts intent to remain enrolled in time-of-use programmes, which may undermine benefits for household finances and energy-reduction goals.

The oxygen reduction reaction, catalysed by platinum, is a crucial process in the operation of fuel cells, but the mechanistic pathways through which it occurs remain a matter for debate. Here, the authors use in situ Raman spectroscopy to identify key intermediates for this reaction at different atomically flat platinum surfaces, shedding light on the mechanism.

Large variations exist in the revenue prediction of grid-scale storage due to uncertainties in operations of storage technologies. Here the authors integrate the economic evaluation of energy storage with key battery parameters for a realistic measure of revenues.

The development of aluminium batteries relies heavily on the discovery of cathode materials that can reversibly insert Al-containing ions. Here the authors show that phenanthrenequinone-based compounds can take up the cationic aluminium complex, leading to promising aluminium batteries.

Ammonia holds promise as a clean energy carrier, but its synthesis requires high pressures and large production scales that are ill-matched to renewable, decentralized energy production. Now, researchers use metal imides to mediate ammonia production in a chemical looping process that operates under mild conditions.

Two-terminal all-perovskite tandem structures are promising as low-cost yet highly efficient solar cells, but their development is limited by the poor quality of the low bandgap absorber layer. Now, a processing method has been shown to enable the production of uniform, thick tin–lead perovskite layers, which translate into improved photovoltaic parameters.