News & Views in 2019

Understanding dendrite formation is key to advancing high-energy-density and safe metallic lithium batteries. With the help of cryogenic electron microscopy, heat is now suggested to play a crucial role in stabilizing lithium metal electrodes by suppressing dendrite growth.

For emerging photovoltaic technologies to become commercially and technically viable, it is important to understand how performance in the laboratory translates to the field. A new study analyses the yearly changes in the energy yield of perovskite solar cells under simulated realistic temperature and irradiance conditions.

Lead in perovskite solar cells is a potential environmental and health hazard if it is released from accidentally damaged panels. Now, the encapsulation of perovskite solar cells with self-healing polymers is shown to significantly reduce the risk of lead leakage from hail impact under a variety of weather conditions.

Photocatalytic H₂ production using semiconductors is a promising approach to store solar energy as a chemical fuel, but the oxidizing power of the excited holes is often wasted. Now, holes are harnessed in a dehydrocoupling strategy that simultaneously produces H₂ and diesel fuel precursors from biomass-derived molecules.

Biomass cooking will continue for the foreseeable future in most developing countries. However, inefficient cookstoves have a negative impact on well-being. While controversy surrounds whether improved biomass cookstoves effectively address this, a new study shows that they may offer economic and health benefits.

Selenium alloying has enabled record efficiency for CdTe solar cells by changing the optoelectronic properties of the CdTe absorber layer, though its role has not yet been fully understood. Now, non-radiative charge-carrier recombination in the bulk of the CdSeTe layer is revealed to be lower in grains with higher Se concentration.

Stationary storage in buildings can help make better use of intermittent renewable power, but safer and cheaper alternatives to lithium-ion batteries are needed to accelerate deployment. Now, demonstration of an aqueous potassium-ion full cell offers a way forward.

Policies that encourage a shift away from solid fuels can improve public health, welfare and the environment. However, impacts and their distribution are rarely evaluated. Now research shows that benefits to home comfort, indoor air quality and well-being from China’s coal-to-electricity programme vary across rich and poor districts.

A significant portion of the energy required to electrochemically reduce CO₂ to fuels and chemicals is typically consumed by the accompanying oxygen evolution reaction. Now, researchers show that alternative oxidative reactions using biodiesel-waste could improve the economics and emission profiles of this process.

While recent gains in the efficiency of photoelectrochemical devices for hydrogen production are encouraging, high efficiency is rarely combined with high power output, which is important for large-scale viability. Towards this goal, researchers now demonstrate a promising thermally integrated device driven by concentrated solar irradiation.

Many governments use finance mechanisms to deliver energy efficiency retrofits, but there is little understanding as to what makes them effective in stimulating private investment. New research now proposes a typology of finance mechanisms that policymakers can use as a toolkit to guide policy design.

In the face of climate change, the transition to a low-carbon energy system has become increasingly urgent. However, the implementation of renewable energy projects is often contested. Now research shows that residents of wind energy communities prefer their local wind project over other means of electricity generation.

Advances in horizontal drilling have significantly increased US oil and gas production, but it is not clear whether the industry is viable if oil prices continue to be low. Researchers now estimate the break-even price for oil and gas from tight formations and analyse the factors that affect investment in drilling rigs.

Scalable interconversion between chemical and electrical energy requires compact, selective and highly efficient reversible electrochemical cells. Now, protonic electrochemical cells with tailored catalysts and ceramic architecture are shown to operate reversibly with high performance and to be integrable with catalytic CO₂ conversion.

Direct liquid fuel cells are usually impeded by the cross-over of their reactants, which depreciates their performances. An asymmetric bipolar membrane is now shown to effectively separate the anolyte and catholyte of a direct borohydride hydrogen peroxide fuel cell, enabling high power and promising durability.

The answer to seasonal energy storage and security to support highly renewable power systems could lie deep under the seabed, where compressed air energy storage offers a route to long-term storage at large scales. Now, research models the potential for this in porous rock and finds a large capacity in saline aquifers offshore in the UK.

The development of solid-state lithium batteries is largely hindered by the undesired lithium dendrite propagation during battery operations. High electronic conductivity of solid electrolytes is now revealed to be the main culprit.

The realization of perovskite nanostructures featuring high emission efficiency and a wide Stokes shift is proving difficult, limiting their impact on luminescent solar concentration technology. Now, engineered exciton routing within multilayered perovskite nanoplatelets may open a path towards high-performing, low-loss devices.

Control of electron and hole concentrations in semiconductors is a longstanding challenge. Now, by managing defect populations, a p–n homojunction solar cell has been fabricated, opening a new avenue for metal halide perovskite devices.

In contrast to lithium-ion batteries where lithium ions carry the charge, a proton battery, making use of a hydrated Prussian blue analogue electrode, is shown to be able to transmit charges in the fashion of the Grotthuss mechanism, displaying ultrafast-rate and ultralong-life properties.