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Dielectric capacitors with ultrahigh power densities are fundamental energy storage components in electrical and electronic systems. However, a long-standing challenge is improving their energy densities. We report dielectrics with ultrahigh energy densities designed with polymorphic nanodomains. Guided by phase-field simulations, we conceived and synthesized lead-free BiFeO₃-BaTiO₃-SrTiO₃ solid-solution films to realize the coexistence of rhombohedral and tetragonal nanodomains embedded in a cubic matrix. We obtained minimized hysteresis while maintaining high polarization and achieved a high energy density of 112 joules per cubic centimeter with a high energy efficiency of ~80%. This approach should be generalizable for designing high-performance dielectrics and other functional materials that benefit from nanoscale domain structure manipulation.

Batteries based on multivalent metals have the potential to meet the future needs of large-scale energy storage, due to the relatively high abundance of elements such as magnesium, calcium, aluminium and zinc in the Earth’s crust. However, the complexity of multivalent metal-ion chemistries has led to rampant confusions, technical challenges, and eventually doubts and uncertainties about the future of these technologies. In this Review, we clarify the key strengths as well as common misconceptions of multivalent metal-based batteries. We then examine the growth behaviour of metal anodes, which is crucial for their safety promises but hitherto unestablished. We further discuss scrutiny of anode efficiency and cathode storage mechanism pertaining to complications arising from electrolyte solutions. Finally, we critically review existing cathode materials and discuss design strategies to enable genuine multivalent metal-ion-based energy storage materials with competitive performance. Batteries based on multivalent metal anodes hold great promise for large-scale energy storage but their development is still at an early stage. This Review surveys the main complexity arising from anodes, electrolytes and cathodes, and offers views on the progression path of these technologies.

The presence of plastic in the environment has sparked discussion amongst scientists, regulators and the general public as to how industrialization and consumerism is shaping our world. Here we discuss restrictions on the intentional use of primary microplastics: small solid polymer particles in applications ranging from agriculture to cosmetics. Microplastic hazards are uncertain, and actions are not similarly prioritized by all actors. In some instances, replacement is technically simple and easily justified, but in others substitutions may come with more uncertainty, performance questions and costs. Scientific impact assessment of primary microplastics compared to their alternatives relies on a number of factors, such as microplastic harm, existence of replacement materials and the quality, cost and hazards of alternative materials. Regulations need a precise focus and must be enforceable by these measurements. Policymakers must carefully evaluate under which contexts incentives to replace certain microplastics can stimulate innovation of new, more competitive and environmentally conscious materials. Plastic pollution is recognized as a global threat, but policy hurdles and a lack of effective plastic substitutes contribute to the problem. In this Perspective, the authors argue that an effective and sustainable path forward must rely on key restrictions and regulations optimized for impact and efficacy.

The development of low-cost and long-lasting all-climate cathode materials for the sodium ion battery has been one of the key issues for the success of large-scale energy storage. One option is the utilization of earth-abundant elements such as iron. Here, we synthesize a NASICON-type tuneable Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 )/C nanocomposite which shows both excellent rate performance and outstanding cycling stability over more than 4400 cycles. Its air stability and all-climate properties are investigated, and its potential as the sodium host in full cells has been studied. A remarkably low volume change of 4.0% is observed. Its high sodium diffusion coefficient has been measured and analysed via first-principles calculations, and its three-dimensional sodium ion diffusion pathways are identified. Our results indicate that this low-cost and environmentally friendly Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 )/C nanocomposite could be a competitive candidate material for sodium ion batteries. Here Chou and co-authors demonstrate a NASICON-type low-cost Fe-based cathode material for sodium ion batteries. Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) allows for long-term cycling and high-power density and is featured by its air stability and all-climate property with 3D diffusion pathways for Na + ions.

The development of sustainable polymers that possess useful material properties competitive with existing petroleum-derived polymers is a crucial goal but remains a formidable challenge for polymer science. Here we demonstrate that irreversible ring-opening polymerization (IROP) of biomass-derived five-membered thionolactones is an effective and robust strategy for the polymerization of non-strained five-membered rings—these polymerizations are commonly thermodynamically forbidden under ambient conditions, at industrially relevant temperatures of 80–100 °C. Computational studies reveal that the selective IROP of these thionolactones is thermodynamically driven by S/O isomerization during the ring-opening process. IROP of γ-thionobutyrolactone, a representative non-strained thionolactone, affords a sustainable polymer from renewable resources that possesses external-stimuli-triggered degradability. This poly(thiolactone) also exhibits high performance, with its key thermal and mechanical properties comparing well to those of commercial petroleum-based low-density polyethylene. This IROP strategy will enable conversion of five-membered lactones, generally unachievable by other polymerization methods, into sustainable polymers with a range of potential applications. Five-membered lactones are common in nature and are produced in large quantities from biomass, but a lack of ring strain means that ring-opening polymerization is usually thermodynamically unfavourable at ambient conditions. Now, an irreversible ring-opening polymerization of biomass-derived five-membered thionolactones—driven by S/O isomerization—has been developed, enabling their conversion into sustainable polymers at industrially relevant temperatures.

The development of sustainable plastics from abundant renewable feedstocks has been limited by the complexity and efficiency of their production, as well as their lack of competitive material properties. Here we demonstrate the direct transformation of the hemicellulosic fraction of non-edible biomass into a tricyclic diester plastic precursor at 83% yield (95% from commercial xylose) during integrated plant fractionation with glyoxylic acid. Melt polycondensation of the resulting diester with a range of aliphatic diols led to amorphous polyesters ( M n  = 30–60 kDa) with high glass transition temperatures (72–100 °C), tough mechanical properties (ultimate tensile strengths of 63–77 MPa, tensile moduli of 2,000–2,500 MPa and elongations at break of 50–80%) and strong gas barriers (oxygen transmission rates (100 µm) of 11–24 cc m −2  day −1  bar −1 and water vapour transmission rates (100 µm) of 25–36 g m −2  day −1 ) that could be processed by injection moulding, thermoforming, twin-screw extrusion and three-dimensional printing. Although standardized biodegradation studies still need to be performed, the inherently degradable nature of these materials facilitated their chemical recycling via methanolysis at 64 °C, and eventual depolymerization in room-temperature water. Functionalizing an intact carbohydrate core with acetals allows for the dramatically simplified production of a plastic precursor directly during the initial fractionation of non-edible biomass. When polymerized, the rigid and polar carbohydrate core also leads to bioplastics with competitive material and end-of life properties.

The current materials predominately come from fossil feedstocks and minerals. The pressures from climate change and plastic pollution challenge us to develop a bioeconomy, replacing petroleum-based products with bio-based and biodegradable products. Cellulose emerges as a versatile biopolymer to make hydrogels for absorbents, aerogels for insulation, membranes for filters, films for packaging, and fibers for textiles and reinforcements. Wood-based cellulose is increasingly perceived by relevant stakeholders to be renewable, biodegradable, and sustainable. Can the properties of cellulose-based materials compete with conventional synthetic materials? Knowledge and discoveries concerning cellulose properties and applications are scattered throughout the scientific literature base. This paper surveys the mechanical properties of cellulose-based materials in the literature using tensile properties as indicators and visualizes the data compared with other competitive materials. The goal is to provide insights into the potential and challenges of using cellulose-based products to replace synthetic materials for a sustainable society.Graphic abstract

Soft robots hold promise for well-matched interactions with delicate objects, humans and unstructured environments owing to their intrinsic material compliance. Movement and stiffness modulation, which is challenging yet needed for an effective demonstration, can be devised by drawing inspiration from plants. Plants use a coordinated and reversible modulation of intracellular turgor (pressure) to tune their stiffness and achieve macroscopic movements. Plant-inspired osmotic actuation was recently proposed, yet reversibility is still an open issue hampering its implementation, also in soft robotics. Here we show a reversible osmotic actuation strategy based on the electrosorption of ions on flexible porous carbon electrodes driven at low input voltages (1.3 V). We demonstrate reversible stiffening (~5-fold increase) and actuation (~500 deg rotation) of a tendril-like soft robot (diameter ~1 mm). Our approach highlights the potential of plant-inspired technologies for developing soft robots based on biocompatible materials and safe voltages making them appealing for prospective applications. Plant-inspired osmotic actuation has been proposed as a competitive actuation strategy yet reversibility is still an open issue hampering its implementation in soft robotics. Here the authors show a low input voltage reversible osmotic actuation strategy based on the electrosorption of ions on flexible electrodes.

Graphene nanoribbons (GNRs) are a family of one-dimensional (1D) materials with a graphitic lattice structure. GNRs possess high mobility and current-carrying capability, sizeable bandgap and versatile electronic properties, which make them promising candidates for quantum electronic applications. In the past 5 years, progress has been made towards atomically precise bottom-up synthesis of GNRs and heterojunctions that provide an ideal platform for functional molecular devices, as well as successful production of semiconducting GNR arrays on insulating substrates potentially useful for large-scale digital circuits. With further development, GNRs can be envisioned as a competitive candidate material in future quantum information sciences. In this Perspective, we discuss recent progress in GNR research and identify key challenges and new directions likely to develop in the near future.Graphene nanoribbons are an emerging class of 1D materials hosting rich quantum-confined and topological states. This Perspective discusses recent breakthroughs in graphene nanoribbon materials and devices, and identifies key challenges towards electronics and quantum information applications.

Metal halide perovskites are promising candidates for room-temperature gamma-ray spectrum detectors; however, it is hard to grow high-quality single crystals that are performance competitive with existing materials. Here we report the growth of centimetre-sized formamidinium-caesium lead bromide (FACsPbBr3) single crystals at high yield from low-purity (98%) precursors using a solution method. The introduction of formamidinium into CsPbBr3 reduces defect density in crystals by eliminating the phase transition upon cooling from growth temperature to room temperature. A mixed solvent is applied to match the solubility slopes of CsPbBr3 and FAPbBr3, resulting in successful incorporation of caesium into FAPbBr3 at FA:Cs ratios from 0 to 1. As-grown FACsPbBr3 exhibits a high resistivity of 9.5 × 109 Ω cm, balanced hole and electron mobility-lifetime products of (2.2–3.2) × 10−3 cm2 V−1, and a record low deep trap density of 5.6 × 1010 cm−3, yielding a high charge collection efficiency of 84% under gamma-rays. FACsPbBr3 spectrum detectors achieve an energy resolution of 2.9% for 662 keV 137Cs γ-rays. Over 65% of the FACsPbBr3 crystals exhibit good γ-ray spectral performance. FACsPbBr3 single crystals show excellent stability under large biases of up to 1,000 V and no degradation of spectrum performance after seven months.Centimetre-sized formamidinium-caesium lead bromide (FACsPbBr3) single crystals were grown at high yield from low-purity precursors. High (84%) charge collection efficiency and energy resolution (2.9% for 662 keV 137Cs) for γ-rays were demonstrated.