Reviews & Analysis

CO₂ capture and its electrochemical conversion to valorized products are energy-intense processes. Now, researchers report that judicious control of the electrode interface and reactant transport unlock a lower energy pathway allowing direct conversion of CO₂ from the captured state to CO.

Performance breakthroughs in rechargeable batteries are regularly reported in academic publications. Here the authors closely examine literature data on aluminium batteries and offer a realistic perspective on the technology.

Electrochemical reduction of CO₂ is a route to synthesize carbon-based products using renewable energy, but achieving high selectivity to specific molecules remains demanding. Inspired by enzymes, a nanoparticle–ligand assembly is now reported that has a floating interlayer, which enhances CO₂ to CO conversion efficiency.

Mg-ion diffusion in cathodes and dissociation in electrolyte complexes are sluggish processes that hinder the development of Mg batteries. Now, a new design of both the cathode and the electrolyte drastically improves the kinetics of these processes, leading to a high-power Mg battery.

Electrocaloric cooling devices traditionally comprise sub-millimetre-thick ceramic working bodies surrounded by relatively massive apparatus. Now, cooling devices that are each based on a thin polymer layer have been stacked to yield a composite lightweight device that pumps heat across a wide temperature span.

Wind energy repowering decisions are multifaceted and depend on the physical, political and social landscape, as factors such as noise regulation, aesthetics and political bargaining can significantly influence project development. Policy should recognise that a technology perspective alone cannot inform implementation pathways and should be supplemented with an understanding of the political and social dimensions.

Given the benefits of improved health and reduced cooking time, women are assumed to unequivocally prefer clean cooking fuels. Now research indicates that women using firewood and those using cleaner alternatives both believe their cooking fuel supports their well-being in several ways, suggesting more complex trade-offs in fuel choices.

Households reduced their electricity use the most when they learnt both that they were using more energy than their neighbours and that energy conservation was socially approved. This suggests that efforts to use social information to nudge conservation should combine different types of social feedback to maximize impact.

Social norm interventions are widely used to foster residential resource conservation. Now researchers have shown that the effectiveness of providing information about others’ energy use alongside messages of social approval for energy savings behaviour depends on the strength and consistency of these messages.

Microwave heating has become a useful tool in catalysis to obtain chemical products under unconventional reaction conditions. Now, researchers have demonstrated low-temperature water splitting to produce hydrogen using microwave catalysis and revealed the important role of reduced oxides in the process.

Ultrathin solar cells attract interest for their relatively low cost and potential novel applications. Here, Massiot et al. discuss their performance and the challenges in the fabrication of ultrathin absorbers, patterning of light trapping structures and ensuring efficient charge-carrier collection.

The design of research solar cells is typically optimized for laboratory conditions but in the real world they are exposed to changing temperatures influencing their performance. Now, research from outdoor tests reveals how temperature alters the current of perovskite/silicon tandem solar cells and how this changes the optimal bandgaps.

Current collectors are essential components in lithium-ion batteries, but are typically made of metal foils that do not contribute to the battery capacity. Now, a fire-extinguishing lightweight polymer-based current collector is developed that enhances both the energy density and safety of the battery.

Mental accounting refers to the mental budgets people use to organize and track resource use. In this Perspective, the authors demonstrate how principles of mental accounting can be applied to energy behaviour and decision-making, and outline future research directions.

Government programmes such as the Advanced Research Projects Agency-Energy (ARPA-E) are designed to help cleantech companies overcome startup challenges and bring innovations to market. New analysis shows that support from ARPA-E has led to higher patenting rates but success in winning follow-up funding remains unclear.

Startups funded by the US Advanced Research Projects Agency – Energy filed patents at twice the rate of similar cleantech firms. The high-risk high-reward funding model has succeeded in advancing energy technology, but more is needed to help these innovative firms cross the valley of death and bring new cleantech products to market.

The landscape of the global clean energy industry is transforming, with many technology-following firms in developing countries rapidly catching up to — and potentially poised to overtake — leaders in the developed world. New analysis reveals a clearer picture of this changing geography of clean energy value chains over time.

Non-fullerene acceptors have enabled record power conversion efficiencies in organic solar cells, but it is unclear how they achieve efficient electron–hole separation. New research shows that extremely long exciton lifetimes are essential to ensure that charges are generated efficiently.

Photocatalytic systems for CO₂ conversion to fuels tend to suffer from low selectivity, and sacrificial reagents or external bias are often required to make the reaction work. Now, a wireless and stand-alone photocatalyst device is demonstrated that converts CO₂ and water into formate and O₂ using solar energy without external bias.

Zinc metal batteries (ZMBs) provide a promising alternative to lithium metal batteries but share the formidable challenges in reversibility. The authors discuss the key performance metrics of ZMBs and propose a protocol to assess the true reversibility of zinc metal anodes.