The need to power off-grid electronics such as Internet-of-Things (IoT) sensors has stimulated extensive research on energy conversion from the environment into electricity. However, it is challenging to provide sustainable electricity at night when photovoltaic systems no longer operate. In this work, we demonstrate a low-cost continuous electricity generator to convert the diurnal temperature variation to electricity via a charging-free thermally regenerative electrochemical cycle (TREC) with the assistance of graphene as a bifunctional solar absorber and radiative cooler. This TREC system with lithium ferrocyanide and lithium iron phosphate can achieve a thermoelectric efficiency of 19.91% relative to Carnot efficiency, almost five times the highest efficiency of reported charging-free TRECs. The maximum power density also exceeds ten times the best reported charging-free TRECs. The experimental rooftop demonstration shows its practical capability for self-power supply at both daytime and night with greatly enhanced power density compared with other thermoelectric generators at night.

Thousands of articles have been reported to enhance the electrochemical stability/reversibility of the Zn-metal anode (ZMA). However, some scientific concepts, engineering factors, mechanism models, and characterization limitations are still not comprehensively understood. Here, based on fair experiments, we proposed ten critical concerns on ZMAs, including the following: (1) scientific concepts misunderstanding on basic electrochemistry and crystallography terms, (2) non-scientific engineering factors affecting Coulombic efficiency (CE) assessment based on operation modes and “edge effect,” and cell parameters on regulating battery performance, (3) influence mechanisms of coating modifications and Zn4(OH)6SO4·xH2O (ZHS) byproduct, and (4) limitations of typically used characterization tools and accuracy of advanced in situ technique paradigms. We not only proposed existing dilemmas but also provided the right medicine for corresponding pains. This perspective hopes to awaken research status of blind advance on aqueous zinc batteries and provide constructive guidance for building theory models and designing modification strategies to meet the challenges of energy storage scientifically and effectively.

Gregor Semieniuk (PhD, Economics, New School for Social Research) is Assistant Research Professor of Economics at the University of Massachusetts Amherst. He researches the political economy of rapid, policy-induced structural change required for the transition to a low-carbon economy. Gregor has published widely on this topic, won grants to study it, and regularly speaks to policy and academic audiences, most recently testifying on stranded fossil-fuel assets before the US Senate Committee on the Budget. Previously, Gregor was on the faculty at SOAS University of London and University of Sussex, and he is an Honorary Professor at University College London.Lucas Chancel is an Associate Professor of Economics at Sciences Po and co-director of the World Inequality Lab at the Paris School of Economics, as well as a Visiting Associate Professor at Harvard. He is the author of dozens of research articles and book chapters on global inequality and environmental issues. He coordinates and edits the World Inequality Reports, which present the latest data on global economic and environmental inequality. His work has attracted media and policy attention worldwide and his book, “Unsustainable inequalities” (Harvard University Press, 2020), featured in the Financial Times and Nature’s best books of the year.Eulalie Saïsset is a specialist in environmental public policies and resulting inequalities. She is a graduate engineer from Mines Paris where she focused on the sociological and political dimensions of the environmental transition. She also holds a master’s degree in public policy and development economics from the Paris School of Economics, where her dissertation focused on the redistributive aspects of stranding fossil fuel assets. Eulalie previously worked at the World Bank in Washington DC as a transport consultant for the Africa region. She also carried out the analysis of European industrial decarbonization policies at the think-tank La Fabrique de l’Industrie.Philip B. Holden completed his DPhil in computational modeling of X-ray lasers in 1991, after which he held research positions in the University of York, Université Paris-Sud, and the Czech Institute of Physics. He then spent 10 years in the finance sector, designing and modeling approximately $2 billion of “big ticket” asset financings. He returned to academia via an MSc in Quaternary Science from the University of London (RHUL/UCL) and joined the Open University in 2007. Phil’s main focus now is the development of computationally efficient Earth system models, with particular focus on interdisciplinary applications and integrated assessment.Dr. Jean-Francois Mercure is Senior Climate Economist at the World Bank and Associate Professor in Climate Policy at the Global Systems Institute, University of Exeter, UK. His research focuses on developing theory, models, and methods for public policy appraisal in climate policy, and for assessing the effectiveness and socio-economic impacts of diverse types of low-carbon, energy, and other climate policies. He also develops methods to understand and assess climate-related financial risks. He co-leads two major programs at the World Bank on analytical tool development and capacity development for finance ministries.Neil R. Edwards is Professor of Earth System Science and University Lead for Sustainability Research at The Open University, UK. After studying mathematics at Cambridge and Leeds Universities, Neil became deeply involved with the early development of comprehensive Earth system models in the 1990s, playing a key role in developing the grid-enabled integrated Earth system (GENIE) framework and related models. Through GENIE, he contributed to the multi-millennial climate projections of the fourth and fifth IPCC assessment reports and has published extensively on climate dynamics, integrated assessment and climate impact modeling, and uncertainty quantification. He has published over 100 refereed papers.

The molecular-level design of non-fullerene acceptors (NFAs) is crucial for enhancing the efficiency of polymer solar cells (PSCs). Here, we investigate the influence of NFA symmetry on bulk-heterojunction (BHJ) PSC performance. Our study introduces a series of closely related asymmetric NFA architectures (A-D-D type and A-DA'D-D type) and compares them with traditional symmetric NFAs. We find that BHJ PSCs using symmetric NFAs outperform those with asymmetric NFAs, achieving power conversion efficiencies (PCEs) of 10%–17% compared with 0.1%–3% for asymmetric NFAs. Analysis reveals that the lower performance of asymmetric NFAs results from disrupted end group-end group stacking in the NFA crystal network, which further causes reduced electron mobility, weaker crystallinity, slower hole transfer, and higher rates of exciton recombination in BHJ blends. These findings provide valuable insights for designing high-performance NFAs in the future.

Assigning oxidation states and understanding the oxygen redox mechanism is crucial for designing superior cathode materials in lithium-ion batteries. The working mechanism of stoichiometric LiNiO2 has been regarded as Ni-dominant redox with partial O contribution through covalent Ni-O bonding for several decades. However, in this issue of Joule, Morris, Grey, and co-workers reported that Ni rarely participates in the redox reaction, and oxygen primarily acts as the redox center through a combination of experimental analysis and computational prediction. Also, the highly reactive singlet O2 formation mechanism was elucidated. This work provides an opportunity to reassess the current understanding of conventional cathode materials.

Granular energy technologies with smaller unit sizes and costs deploy faster, create more jobs, and distribute benefits more widely than lumpy large-scale alternatives. These characteristics of granularity align with the aims of fiscal stimulus in response to COVID-19. We analyze the technological granularity of 93 green recovery funding programs in France, Germany, South Korea, and the UK that target £72.9 billion for low-carbon energy technologies and infrastructures across five emissions-intensive sectors. We find that South Korea’s “New Deal” program is the most technologically granular with strong weighting toward distributed renewables, smart technologies, electric vehicle charge points, and other relatively low unit cost technologies that are quick to deploy. The UK has the least granular portfolio, concentrating large amounts of public money on small numbers of mega-scale energy projects with high implementation risks. We demonstrate how technological granularity has multiple desirable characteristics of green recovery: jobs, speed, and distributed benefits.

Overcooling is a major challenge of conventional passive radiative cooling materials, especially for thermal regulation of houses, electric vehicles, and space objects. In a recent paper published in Device, Qiao and co-workers reported a Janus film system that keeps objects cool in hot-weather daytime and warm in cold-weather nighttime.

To maximize product purity, current density and efficiency has never been demonstrated simultaneously for the membrane-less water electrolyzers that eliminate the use of a membrane or a diaphragm, as well as their unfavorable issues. Here, we successfully addressed the trade-offs by leveraging the rose-petal-effect-mimetic (RPEM) design strategy. We mimicked nature by alternating water-repellent and water-adhesive building blocks; the resultant RPEM electrode is in the Cassie-impregnating wetting state, which is ideal for efficient bubble-less gas evolution reactions. A bubble-less HER at a current density of 4.2 A cm−2, one order of magnitude larger than that of any known bubble-less electrodes, was demonstrated by the RPEM electrode. Based on this, we further constructed the RPEM electrolyzer and demonstrated membrane-less water electrolysis at 1 A cm−2 current density, simultaneously with 61.5% electrolysis efficiency and 0.003% hydrogen crossover, remarkably outperforming the state-of-the-art membrane-less water electrolyzer.

The surface-confined interfacial water at graphene exhibits highly localized changes in applied electric fields, thus playing an important role in energy-related fields. However, detecting the unique signals from surface-confined interfacial water located at the two-phase boundary is notoriously difficult owing to the complex and confined environment. This difficulty is compounded further when studying surface-confined interfacial water on atom-thick graphene surfaces. Now, by assembling graphene at atomically ordered Au(111) single-crystal surfaces, we utilize in situ Raman spectroscopy and ab initio molecular dynamics simulations to characterize the surface-confined interfacial water on graphene. Interfacial water predominantly consists of hydrogen-bonded or cation-coordinating water molecules. Dynamic potential-dependent transformations in the water structure are directly observed, whereby water changes from a parallel configuration to a one-H down and then to a two-H down structure. These results are an essential step toward understanding the fundamental processes of surface-confined interfacial water at graphene surfaces and guiding the design of an efficient electrocatalytic interface.

Small-area photoelectrodes are used to study fundamental science and material development for photoelectrochemical (PEC) water splitting cells at the laboratory scale. For practical applications, however, one needs to develop scalable geometrical designs and architectures of large photoelectrodes as well as their fabrication using low-cost, solution-processed, scalable methods. In this perspective, we first discuss the device physics concepts for developing large photoelectrodes using dimensional engineering (size, geometry, shape, and structures) and scalable architectures (such as symmetric and asymmetric designs with gridlines as well as monolithically integrated modules with interconnections), similar to the earlier development of large thin-film photovoltaic cells. Finally, we propose a novel and strategic protocol to fabricate these designs for the development of large-photoelectrode modules via commercially deployable, fully inkjet-printing as a solution processed thin-film deposition method.

The recent report by Heenan et al.1 in Nature demonstrated two advanced synchrotron-based X-ray diffraction (XRD) methods to characterize internal cell temperature along with state-of-charge and mechanical strain within cylindrical lithium-ion cells at high rates. The non-destructive internal temperature evaluation method could further enlighten battery degradation, improve design, and enable innovative management, thus resulting in more durable and safer batteries.

Finding a sustainable strategy to produce hydrogen fuel with sunlight is a long-standing challenge. In a recent issue of Nature Communications, Xu et al. show that coating photosynthetic algae with a protective inorganic shell, creating bionic algae, improves their potential to produce solar hydrogen.

High-entropy electrocatalysts (HEECs) have been attracting extensive attention because of their multiple merits in heterogeneous catalysis. However, the diverse local environments and vast phase space behind HEECs make experimental and ab initio exploration unaffordable. In this work, we develop an accurate and efficient atomic graph attention (AGAT) network to accelerate the design of high-performance HEECs. The reliability of scaling relations and classical d-band theory is confirmed on HEEC surfaces on a statistical basis. Nonetheless, we prove that HEEC can effectively bypass the scaling relations by providing ample versatile local environments. We apply the model to explore the compositional space composed of Ni-Co-Fe-Pd-Pt, and high-performance compositions are recommended and validated by our experiments. The AGAT is inherently interpretable, as attention scores elegantly explain its behavior, which shows good agreement with physical principles. Through the interpretable AGAT model, this work opens an avenue for rational design and high-throughput screening of high-performance HEECs.

The solvation capacity of dispersion solvents plays a crucial role in the solution processing of metal halide perovskites. For instance, N,N-dimethylformamide (DMF), a widely used dispersion solvent, possesses high solvation capacity but often generates suboptimal film quality due to slow crystallization kinetics. We propose using low-solvation binary cosolvents (nitrile- and ether-type solvents) to achieve a balance between solvation (i.e., sufficient solubility of precursors) and desolvation (i.e., rapid crystallization of films) processes during perovskite synthesis. The polarity and hydrogen-bonding property of these cosolvents synergistically enhance their solvation capacity, facilitating perovskite precursor dissolution. Moreover, the low-solvation cosolvents accelerate the crystallization of well-defined intermediate films, yielding higher-quality perovskites than those synthesized with DMF. The optimized modules achieved an active-area efficiency of 22.27%, with a certified aperture-area efficiency of 16.10% and corresponding active-area efficiency of 20.75%. This research on solvation regulation provides universal guidelines for innovatively preparing high-quality halide perovskites.

Michiel Kenis is a PhD researcher at the Energy Systems Integration & Modeling Group at the University of Leuven with a doctoral mandate from the Flemish Institute for Technological Research (VITO). He was a visiting researcher at the Massachusetts Institute of Technology. His research focuses on cross-border electricity markets. He holds a MSc in energy engineering and a MSc in policy economics, both from the University of Leuven.Luca Lanzilao completed his MSc degree in mathematical engineering from Politecnico di Torino in 2018. Currently, he is pursuing a PhD at KU Leuven. His research focuses on studying the response of the atmospheric boundary layer to wind farm forcing, with particular emphasis on meso-scale phenomena, such as gravity waves.Kenneth Bruninx received a MSc degree in energy engineering in 2011, a MSc in management, and a PhD degree in mechanical engineering in 2016, all from the University of Leuven (KU Leuven), Belgium. Currently, he is an assistant professor at the Faculty of Technology, Policy, and Management of TU Delft, Netherlands and a research fellow at the Department of Mechanical Engineering, KU Leuven, Belgium. His research interests include market design, policies, and regulation for integrated energy systems.Johan Meyers is a professor of mechanical engineering at KU Leuven since 2009. His research focuses on the simulation of turbulent flows and the atmospheric boundary layer with applications in wind energy. In 2012, he obtained an ERC grant on wind farm control and has been involved in various European projects on wind energy since. He served as the vice president of the European Academy of Wind Energy from 2017 to 2019 and as its president from 2019 to end of 2021. He has been active as an associate editor for Computers & Fluids and is currently an associate editor for Wind Energy Science.Erik Delarue received MSc and PhD degrees in mechanical engineering from the University of Leuven, Belgium, in 2005 and 2009, respectively. He is currently an associate professor with the University of Leuven, TME Branch (energy conversion) and active with EnergyVille. His research focus and expertise are on quantitative tools, supporting an efficient operation of, and transition toward, a low-carbon energy system (mathematical modeling of energy systems). Applications relate to flexibility through energy systems integration, market design, and energy policies.

Coupling electrochemical and chemical reactions has been demonstrated in traditional tandem reactor systems, but their practical applications are still distilled down to individual reactor optimizations. Here, we demonstrate a fully integrated system that presents significantly improved catalytic performance when compared with traditional tandem systems. Using electrosynthesis of hydrogen peroxide followed by olefin epoxidation reaction as a representative example, we demonstrated that, by confining the chemical reaction right at the electrode/electrolyte interface in our solid electrolyte reactor, we can fully leverage the interfacial high concentration of H2O2 product from electrocatalysis to boost the following ethylene epoxidation reaction, which represented a 3-fold improvement in electrolyte-free ethylene glycol generation when compared with a tandem reactor system. This integration strategy can be extended to other electrochemical-chemical coupling reactions, especially when the coupled reaction is sensitive to reactant concentrations, which could avoid energy-intensive separation or concentration steps typically needed between the electrochemical and chemical reactions.

Aqueous acidic batteries are a good choice to respond to battery diversity, delivering safety, cost, environmental friendliness, and high-power necessary for renewable energy storage. However, the practical adoption is greatly challenged by low voltage and energy density due to the inadequate metal anode materials. Here, we report an interfacial regulated Sn metal anode as the solution of the last piece of the puzzle. The ease of recycling, low potential, fast redox kinetics, and high capacity of Sn perfectly fit the battery system, and the Sn metal shedding critical issue is successfully suppressed by promoting uniform deposition for added interaction from alloying. Consequently, this reversible Sn anode with 442 mAh g−1 matches well to different types of cathodes. The as-assembled acidic batteries also demonstrate sufficient output voltage (up to 1.7 V), energy density (up to 312 Wh kg−1 based on both electrodes), kinetics (up to 24 C), and stability (up to 2,400 cycles).

The water-dissociation (WD) reaction (H2O → H+ + OH−) affects the rates of electrocatalytic reactions and the performance of bipolar membranes (BPMs), but how WD is driven by voltage and catalyzed is not understood. We report BPM electrolyzers with two reference electrodes (REs) to measure temperature-dependent WD current and overpotential (ηwd) without soluble electrolyte. Using TiO2-P25-nanoparticle catalyst and Arrhenius-type analysis, we found Ea,wd of 25–30 kJ/mol, independent of ηwd, and a pre-exponential factor proportional to ηwd that decreases ∼10-fold in D2O. We propose a new WD mechanism where metal-oxide nanoparticles, polarized by the BPM-junction voltage, serve as proton (1) acceptors (from water) on the negatively charged side of the particle to generate free OH−, (2) donors on the positively charged side to generate H3O+, and (3) surface proton conductors that connect spatially separate donor/acceptor sites. Increasing electric field with ηwd orients water for proton transfer, increasing the pre-exponential factor, but is insufficient to lower Ea.

Integration of carbon capture with utilization technologies can lead the way to a future net-zero carbon economy. Nevertheless, direct conversion of chemically captured CO2 remains challenging due to its thermodynamic stability. Here, we demonstrate CO2 capture from flue gas or air and its direct conversion into syngas using solar irradiation without any externally applied voltage. The system captures CO2 with an amine/hydroxide solution and photoelectrochemically converts it into syngas (CO:H2 1:2 [captured from concentrated CO2], 1:4 [from simulated flue gas], and 1:30 [from air]) using a perovskite-based photocathode containing an immobilized molecular Co-phthalocyanine catalyst. At the anode, plastic-derived ethylene glycol is oxidized into glycolic acid over a Cu26Pd74 alloy catalyst. The overall process uses flue gas or air as carbon source, discarded plastic waste as an electron donor, and sunlight as the sole energy input. This strategy opens new avenues for future carbon-neutral or even negative solar fuel and waste upcycling technologies.

Alkali hydroxide systems capture CO2 as carbonate; however, generating a pure CO2 stream requires significant energy input, typically from thermal cycling to 900°C. What is more, the subsequent valorization of gas-phase CO2 into products presents additional energy requirements and system complexities, including managing the formation of (bi)carbonate in an electrolyte and separating unreacted CO2 downstream. Here, we report the direct electrochemical conversion of CO2, captured in the form of carbonate, into multicarbon (C2+) products. Using an interposer and a Cu/CoPc-CNTs electrocatalyst, we achieve 47% C2+ Faradaic efficiency at 300 mA cm−2 and a full cell voltage of 4.1 V. We report 56 wt % of C2H4 and no detectable C1 gas in the product gas stream: CO, CH4, and CO2 combined total below 0.9 wt % (0.1 vol %). This approach obviates the need for energy to regenerate lost CO2, an issue seen in prior CO2-to-C2+ reports.