Research articles

Aqueous Li-ion batteries have considerably lower energy density than their non-aqueous counterparts. Here the authors report a room-temperature hydrate metal salt electrolyte that, when coupled with a spinel Li₄Ti₅O₁₂ electrode, displays an energy density of 130 Wh kg⁻¹.

There is intensive research underway into the development of fuel cells. Here, the authors present a proton exchange membrane fuel cell based on quaternary ammonium-biphosphate ion pairs, offering promising performance under a wide range of conditions that are unattainable with conventional technologies.

Solar energy can be used to evaporate water and generate steam, however this usually requires expensive optical concentrators. Ni et al. demonstrate a low-cost solar receiver based on thermal concentration that generates steam at 100 ^∘C without the need for optical concentration.

Carrier recombination in organic solar cells usually limits their optoelectronic performance, in particular their fill factor. Gasparini et al show that adding an ordered polymer to a ternary blend reduces carrier recombination, achieving a fill factor of 77%.

Large-scale adoption of electric vehicles will only occur if the needs of individual drivers are met. Here the authors present a model of the energy consumption of personal vehicles in the USA, allowing an evaluation of the adoption potential of electric vehicles.

Future regional electricity demand will be affected by climate change and population migration. Allen et al. combine predictions of temperature rise and population shift, including in response to extreme weather, to map electricity demand and substation capability in the southern US to 2050.

The significant phase change between gaseous and crystalline oxygen deteriorates the performance of lithium–air batteries. Here the authors report a battery with a cathode consisting of Li₂O and Co₃O₄ nanocomposites, which displays stable cyclability and high energy density, without involving any gas evolution.

Redox-flow batteries with organic-based electrolytes hold many advantages over conventional-flow batteries. Here the authors report a high-performance flow battery based on alloxazine, an aqueous-stable and soluble redox-active organic molecule resembling the backbone structure of vitamin B2.

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.