Research articles

Electrode materials with pores generally have high tortuosity, which is detrimental to battery performance. Here the authors develop a magnetic alignment approach that produces battery electrodes with low-tortuosity porosity and high capacity.

Behavioural interventions targeting children can influence the whole family, making them attractive for energy-saving schemes. Boudet et al. use 30 Girl Scout groups to test interventions on residential and food and transport energy behaviours and find they have potential for increasing energy saving.

A common problem for thick electrodes in lithium-ion batteries is slow ionic transport. Here, the authors present a particle-alignment method that uses a low magnetic field and show that the lithium diffusion path is improved for an aligned thick graphite electrode, leading to a better rate capability.

The photovoltaic properties of hybrid organic–inorganic perovskites are sensitive to the local microstructure, but difficult to quantify at the nanoscale. Leblebici et al. use conductive atomic force microscopy to map the local short-circuit current and open-circuit voltage, finding heterogeneity within individual grains.

One of the major problems in Li–S batteries is the undesired shuttling of lithium polysulfides between electrodes. Here the authors present a metal–organic framework-based separator to mitigate the shuttle effect, leading to stable long cycles.

The efficiency of organic solar cells depends on the timescale of charge separation, with fast separation achieved through large driving forces. Liu et al. show that non-fullerene organic blends exhibit fast charge separation and efficiency of 9.5% even in the presence of only small driving forces.

Heat recovery from sources with temperatures below 100 ^∘C can provide a significant amount of energy, but it is difficult to achieve with current technologies. Straub et al. devise a thermo-osmotic energy conversion process that can generate power from heat sources at temperatures as low as 40 ^∘C.

Increasing generation of clean energy from wind resources will help China meet its 2030 energy-mix target and combat climate change. Davidson et al. model the wind energy generation potential of China, estimating a grid-integrated potential of 2.6 PWh per year in 2030.

The grain boundaries in thin-film perovskite solar cells are responsible for non-radiative carrier recombination, which is deleterious for the optoelectronic performance. Son et al. show how to passivate the grain boundaries by using excess CH₃NH₃I in the precursor solution, achieving efficiencies of 20.4%.

Batteries are promising to support energy systems based on intermittent renewable energy, yet their investment attractiveness remains low. Using a techno-economic model, Stephan et al. find that returns can be increased and risks reduced if batteries are used for multiple stationary applications.

The recent drop in oil prices is having a profound impact on global energy markets, raising questions about how these markets might evolve over the long term. This study uses scenarios to assess the energy and emissions impacts of diverging oil price futures and which uncertainties they depend upon.

Climate policies are frequently argued to achieve energy independence as an additional benefit. Jewell et al. use five energy-economy models to show that the opposite is not true: constraining energy imports is much cheaper than climate change mitigation but would not significantly reduce emissions.

Several factors, such as wind power curtailment and quality of turbines, cause a reduced capacity of wind energy production in China compared with the US. The authors quantify the relative weight that these factors have in limiting the wind power output in China, and provide policy recommendations.

Soluble catalysts such as redox mediators are promising in enhancing energy efficiency of Li–O₂ batteries. Here, the authors propose a design principle for finding efficient redox mediators and demonstrate the application of such a new catalyst.

The ability of photovoltaic devices to harvest solar energy can be enhanced by tailoring the spectrum of incident light with thermophotovoltaic devices. Bierman et al. now show that one such device achieves a solar-to-electrical efficiency of 6.8%, exceeding that of the solar cell alone.

CdTe solar cells have not reached their full efficiency potential, in part because their voltages have lagged behind those of cells made from other semiconductors. Zhao et al. report monocrystalline CdTe solar cells with open-circuit voltages up to 1.1 V and conversion efficiencies up to 17%.

Power grids often fail during extreme weather events such as hurricanes, leaving millions of customers without electricity. A large-scale analysis of the operation of power grids in an extended geographical area now reveals that such events exacerbate vulnerabilities that are obscured during normal operation.

Efficient catalysts for the oxygen-evolution reaction, especially in alkaline media, are highly desired because of their application in various energy technologies. Now, a gold-supported NiCeO_x catalyst is shown to have excellent catalytic activity due to synergistic geometric and electronic effects.

There is an intensive effort in developing multi-shelled metal oxide nanostructures for lithium-ion battery applications. Now, a metal anion-adsorption mechanism, as opposed to the conventional cation adsorption on carbonaceous templates, is demonstrated in the synthesis of vanadium oxide hollow microspheres, which exhibit excellent battery performance.

Rechargeable aqueous batteries are attractive owing to their relatively low cost and safety. Here the authors report an aqueous zinc/manganese oxide battery that operates via a conversion reaction mechanism and exhibits a long-term cycling stability.