High‐efficiency energy storage technologies and devices have received considerable attention due to their ever‐increasing demand. Na‐related energy storage systems, sodium ion batteries (SIBs) and ...sodium ion capacitors (SICs), are regarded as promising candidates for large‐scale energy storage because of the abundant sources and low cost of sodium. In the last decade, many efforts, including structural and compositional optimization, effective modification of available materials, and design and exploration of new materials, have been made to promote the development of Na‐related energy storage systems. In this Review, the latest developments of micro/nanostructured electrode materials for advanced SIBs and SICs, especially the rational design of unique composites with high thermodynamic stabilities and fast kinetics during charge/discharge, are summarized. In addition to the recent achievements, the remaining challenges with respect to fundamental investigations and commercialized applications are discussed in detail. Finally, the prospects of sodium‐based energy storage systems are also described.
The latest developments of micro/nanostructured electrode materials for sodium‐based electrochemical energy storage devices, sodium ion batteries, and sodium ion capacitors, are reviewed. Especially, the rational design of unique nanocomposites with high thermodynamic stabilities and fast kinetics are comprehensively summarized. On the basis of the recent achievements, the remaining challenges with respect to fundamental investigations and commercialized applications are also discussed along with the prospects of sodium‐based energy storage systems.
Liquid crystal elastomers (LCEs) are active soft matter‐based materials with strong stimulus responsiveness and reversible, large‐shape morphing capabilities. LCEs have demonstrated broad and growing ...applications in soft robotics, wearable devices, artificial muscles, and optical machines. The actuation intelligence and advanced functionality of LCEs depend on the smartness and properties of structures. In this review, we discuss recent advances in structure‐induced intelligence of LCEs, specifically the integration of structural properties with the alignment and processing of LCEs. The structural design principles for three categories consisting of common structures (film, fiber, and tubule), smart structures (origami, kirigami, mechanical metamaterial, topology, and topography), and complex structures (monolithic and integrated) are presented. Various alignment controls of LCEs, including mechanical, surface, field‐assisted, and shear alignment, are capable of inducing structural properties. The coupling and collaboration mechanisms of the LCE structures and the generated functions are discussed. The review concludes with perspectives on current challenges and emerging opportunities.
Liquid crystal elastomers (LCEs) are active soft matter‐based materials with strong stimulus responsiveness and reversible, large‐shape morphing capabilities. The actuation intelligence and advanced functionality of LCEs depend on the smartness and properties of structures. In this review, we discuss recent advances in structure‐induced intelligence of LCEs, specifically the integration of structural properties with the alignment and processing of LCEs.
Graphene, an atomic monolayer of carbon atoms in a honeycomb lattice realized in 2004, has rapidly risen as the hottest star in materials science due to its exceptional properties. The explosive ...studies on graphene have sparked new interests towards graphene-analogous materials. Now many graphene-analogous materials have been fabricated from a large variety of layer and non-layer materials. Also, many graphene-analogous materials have been designed from the computational side. Though overshadowed by the rising graphene to some degree, graphene-analogous materials have exceptional properties associated with low dimensionality and edge states, and bring new breakthrough to nanomaterials science as well. In this review, we summarize the recent progress on graphene-analogous low-dimensional materials (2D nanosheets and 1D nanoribbons) from both experimental and computational side, and emphasis is placed on structure, properties, preparation, and potential applications of graphene-analogous materials as well as the comparison with graphene. The reviewed materials include strictly graphene-like planar materials (experimentally available h-BN, silicene, and BC3 as well as computationally predicted SiC, SiC2, B, and B2C), non-planar materials (metal dichalcogenides, metal oxides and hydroxides, graphitic-phase of ZnO, MXene), metal coordination polymers, and organic covalent polymers. This comprehensive review might provide a directional guide for the bright future of this emerging area.
Heavy monsoon rainfall ravaged a large swath of East Asia in summer 2020. Severe flooding of the Yangtze River displaced millions of residents in the midst of a historic public health crisis. This ...extreme rainy season was not anticipated from El Niño conditions. Using observations and model experiments, we show that the record strong Indian Ocean Dipole event in 2019 is an important contributor to the extreme Yangtze flooding of 2020. This Indian Ocean mode and a weak El Niño in the Pacific excite downwelling oceanic Rossby waves that propagate slowly westward south of the equator. At a mooring in the Southwest Indian Ocean, the thermocline deepens by a record 70 m in late 2019. The deepened thermocline helps sustain the Indian Ocean warming through the 2020 summer. The Indian Ocean warming forces an anomalous anticyclone in the lower troposphere over the Indo-Northwest Pacific region and intensifies the upper-level westerly jet over East Asia, leading to heavy summer rainfall in the Yangtze Basin. These coupled ocean-atmosphere processes beyond the equatorial Pacific provide predictability. Indeed, dynamic models initialized with observed ocean state predicted the heavy summer rainfall in the Yangtze Basin as early as April 2020.
The development of controllable artificial light‐harvesting systems based on liquid crystal (LC) materials, i.e., anisotropic fluids, remains a challenge. Herein, an annulene‐based discotic LC ...compound 6 with a saddle‐shaped cyclooctatetrathiophene core has been synthesized to construct a tunable light‐harvesting platform. The LC material shows a typical aggregation‐induced emission, which can act as a suitable light‐harvesting donor. By loading Nile red (NiR) as an acceptor, an artificial light‐harvesting system is achieved. Relying on the thermal‐responsive self‐assembling ability of 6 with variable molecular order, the efficiency of such 6‐NiR system can be controlled by temperature. This light‐harvesting system works sensitively at a high donor/acceptor ratio as 1000 : 1, and exhibits a high antenna effect (39.1) at a 100 : 1 donor/acceptor ratio. This thermochromic artificial light‐harvesting LC system could find potential applications in smart devices employing soft materials.
An annulene‐based discotic liquid crystal (LC) material to construct a tunable light‐harvesting platform is developed. Relying on the thermal‐responsive self‐assembling ability of the LC molecule with variable molecular order, the efficiency of the light‐harvesting system can be controlled at different temperatures when Nile red is introduced as an acceptor. This system exhibits a high antenna effect (39.1) at a 100 : 1 donor/acceptor ratio.
Featured with unique mechanical, electronic and chemical properties, nitrogen‐doped carbon materials have become the research hotspot of energy storage. As electrode materials in supercapacitors ...(SCs), N‐doped carbons have demonstrated intriguing flexibility and superb performances in a wide electrochemical window, equipped with versatile properties as both cathodes and anodes for constructing high voltage devices. Compared with limited doping level, N‐rich and porous carbon materials (NPCs) are of great desire to release the restricted properties of N species and obtain high specific capacitances (>600 F g−1), pushing the energy density towards the battery level without scarifying the capacitor‐level power ability. In this Research News we firstly discuss the key factors influencing the performance of NPC electrodes to disclose related charge storage mechanisms. In addition, the trade‐off among N‐content, porous structure and electrical conductivity is involved as well as electrochemical behaviors in different electrolytes. Also, various progressive developments are highlighted systematically ranging from asymmetric to symmetric and hybrid configurations, covering both aqueous and non‐aqueous systems. Finally, some stubborn and unsolved problems are summarized, with prospective research guidelines on NPC‐based SCs.
Nitrogen‐rich porous carbons (NPCs) have brought new breakthroughs to supercapacitors (SCs) due to their unique physic‐chemical properties, and progressively pushed the energy density towards the battery level while keeping capacitor‐level power output, realizing high energy‐power integration to bridge the gap among current systems. Further, charge storage fundamentals in NPCs and progressive developments of NPC‐based SC configurations are highlighted systematically.
The exploration of catalysts for energy conversion lies at the center of sustainable development. The combination of experimental and computational approaches can provide insights into the inner laws ...between the catalytic performance and the structural and electronic properties of catalysts. Owing to the inherent advantages of 2D materials over their 3D counterparts, including high specific surface area and abundant surface defects that could provide sufficient active sites, 2D materials are promising candidates and have attracted wide interest in catalysis. Importantly, 2D materials are the most widely computationally investigated models with which to relate computational prediction with experimental confirmation conveniently. Recently, more 2D catalysts have been prepared in experiments while more accurate computational methods have been used to disclose catalytic performance, and explore the mechanism at an atomic level. In this review, recent advances are summarized related to the development and design of 2D electro/photocatalysts. The main emphasis is put on the unique properties of 2D catalysts investigated by the combination of experiments and computations. Computational methods closer to experimental environments are introduced with particular attention to bridge the gap between experiments and computations. In addition, the challenges of computations and experiments are also discussed for 2D catalysts.
2D materials are an important and convenient bridge to connect experiments and computations. Recent advances are summarized related to the development and design of 2D electro/photocatalysts from both experimental and computational perspectives to bridge the gap between them and inspire new ideas for further development of 2D catalysts.
Twisted toroidal ribbons such as the one-sided Möbius strip have inspired scientists, engineers and artists for many centuries. A physical Möbius strip exhibits interesting mechanical properties ...deriving from a tendency to redistribute the torsional strain away from the twist region. This leads to the interesting possibility of building topological actuators with continuous deformations. Here we report on a series of corresponding bi-layered stripe actuators using a photothermally responsive liquid crystal elastomer as the fundamental polymeric material. Employing a special procedure, even Möbius strips with an odd number of twists can be fabricated exhibiting a seamless homeotropic and homogeneous morphology. Imposing a suitable contraction gradient under near-infrared light irradiation, these ribbons can realize continuous anticlockwise/clockwise in-situ rotation. Our work could pave the way for developing actuators and shape morphing materials that need not rely on switching between distinct states.
Density functional theory (DFT) computations were performed to investigate the electronic properties and Li storage capability of Ti3C2, one representative MXene (M represents transition metals, and ...X is either C or/and N) material, and its fluorinated and hydroxylated derivatives. The Ti3C2 monolayer acts as a magnetic metal, while its derived Ti3C2F2 and Ti3C2(OH)2 in their stable conformations are semiconductors with small band gaps. Li adsorption forms a strong Coulomb interaction with Ti3C2-based hosts but well preserves its structural integrity. The bare Ti3C2 monolayer exhibits a low barrier for Li diffusion and high Li storage capacity (up to Ti3C2Li2 stoichiometry). The surface functionalization of F and OH blocks Li transport and decreases Li storage capacity, which should be avoided in experiments. The exceptional properties, including good electronic conductivity, fast Li diffusion, low operating voltage, and high theoretical Li storage capacity, make Ti3C2 MXene a promising anode material for Li ion batteries.
Renewable energy applications largely rely on transition metal catalysts. Similar to organocatalysts, p-block elements exhibit transition-metal-like catalytic performances. Si Zhou and co-workers ...review the latest advances in p-block elements as catalysts for energy conversion to deeply understand the concept of metal-free catalysis and establish the design principles for p-block catalysts.
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