Reviews & Analysis

Oxygen reduction at the cathode of fuel cells typically requires a platinum-based material to catalyse the reaction, but lower-cost, more stable catalysts are sought. Now, an intrinsically conductive metal–organic framework based on cheaper elements is shown to be a durable, structurally well-defined catalyst for this reaction.

Rechargeable aqueous batteries are attractive energy storage technologies owing to their low cost and high safety, but suffer from poor electrochemical performance. Now, an aqueous mild-acid-based Zn/MnO₂ battery that operates via a conversion mechanism is shown to have a long-term cycling stability.

Current approaches to energy systems invoke individual rational consumers, despite the fact that their decision-making cannot be simplified so readily. This Perspective explores the concept of consumers as part of a wider transition, offering a typology of the users who are shaping and enacting system change.

Meeting carbon emissions commitments while providing necessary energy services means reducing fossil fuel consumption. This Review presents social science insights for increasing adoption of low-carbon and low-consumption technologies and engendering practice changes among households and organizations.

When making decisions about energy, consumers and policymakers typically overlook moral issues, which can have profound societal consequences. This Perspective explores how ideas from justice and ethics can provide a framework to reconsider energy problems and better inform decision-making processes.

The resilience of distribution power grids is put to the test by daily operations as well as by extreme weather events such as hurricanes. An analysis of blackout data in upstate New York now reveals that larger blackouts have a disproportionate effect on grid reliability.

Doping graphitic materials is desirable to enhance their performance for energy conversion and storage applications, but achieving high dopant concentrations remains a challenge. Researchers now demonstrate synthesis of such materials with very high doping levels and facile tunability.

Public investment in science and technology is critical for meeting future energy needs, although understanding its impact has remained unclear. Now, an analysis of publications resulting from government funding sheds light on its outcomes and the timescales required to see them.

Materials with high ionic conductivity are urgently needed for the development of solid-state lithium batteries. Now, an inorganic solid electrolyte is shown to have an exceptionally high ionic conductivity of 25 mS cm⁻¹, which allows a solid-state battery to deliver 70% of its maximum capacity in just one minute at room temperature.

Waste heat can be converted to electricity by thermoelectric generators, but their development is hindered by the lack of cheap materials with good thermoelectric properties. Now, carbon-nanotube-based materials are shown to have improved properties when purified to contain only semiconducting species and then doped.

The capture, storage and conversion of gases such as hydrogen, methane and carbon dioxide may play a key role in the provision of carbon-neutral energy. This Review explores the role of metal–organic frameworks — porous networks of metal ions or clusters connected by organic linkers — for such applications.

Small-scale renewable energy systems and smart technologies are enabling energy consumers to become producers and service providers as well. This Perspective explores this ‘prosumption’ phenomenon, highlighting three promising prosumer market models and the challenges for future implementation.

Tracking the Sun's motion in concentrating photovoltaics by rotating the whole system is impractical and hinders commercial deployment. Instead, integrated-tracking approaches, which are discussed in this Review, are more suitable for low-cost, rooftop applications.

The chemistry of the discharge products of metal–oxygen batteries is related to the battery's efficiency but knowledge of their formation mechanism is incomplete. Now, the initial discharge product in sodium–oxygen batteries is shown to be sodium superoxide, which undergoes dissolution and then transforms to sodium peroxide dihydrate.

The oxidation of water is essential to the sustainable production of fuels using sunlight or electricity, but designing active, stable and earth-abundant catalysts for the reaction is challenging. Now, a complex containing five iron atoms is shown to efficiently oxidize water by mimicking key features of the oxygen-evolving complex in green plants.

The transport sector must undergo radical changes if it is to reduce its carbon emissions, calling for alternative vehicles and fuel types. Researchers now analyse the expectation cycles for different fuel technologies and draw lessons for the role of US policy in supporting them.

The performance of CdTe solar cells — cheaper alternatives to silicon photovoltaics — is hampered by their low output voltages, which are normally well below the theoretical limit. Now, record voltages of over 1 V have been reported in single-crystal CdTe heterostructure solar cells, which are close to those of benchmark GaAs cells.

Solar cells based on solution-processed colloidal quantum dots are promising alternatives to conventional devices. This Review discusses recent advances and outstanding challenges for the field of quantum dot solar cells towards their commercialization.

Micrometre-sized silicon particles are attractive negative-electrode materials for lithium-ion batteries but are prone to mechanical failure during electrochemical cycling. Now, graphene cages grown conformally around the micro-silicon particles are shown to improve their cycling stability.

Improving the design of catalytic materials for clean energy production requires a better understanding of their electronic properties, which remains experimentally challenging. Researchers now quantify the number of electrons transferred from metal nanoparticles to an oxide support as a function of particle size.