Due to the obvious advantage in potassium reserves, potassium‐ion batteries (PIBs) are now receiving increasing research attention as an alternative energy storage system for lithium‐ion batteries ...(LIBs). Unfortunately, the large size of K+ makes it a challenging task to identify suitable electrode materials, particularly cathode ones that determine the energy density of PIBs, capable of tolerating the serious structural deformation during the continuous intercalation/deintercalation of K+. It is therefore of paramount importance that proper design principles of cathode materials be followed to ensure stable electrochemical performance if a practical application of PIBs is expected. Herein, the current knowledge on the structural engineering of cathode materials acquired during the battle against its performance degradation is summarized. The K+ storage behavior of different types of cathodes is discussed in detail and the structure–performance relationship of materials sensitive to their different lattice frameworks is highlighted. The key issues facing the future development of different categories of cathode materials are also highlighted and perspectives for potential approaches and strategies to promote the further development of PIBs are provided.
Potassium‐ion batteries (PIBs) are now receiving increasing research attention due to their obvious advantage regarding the potassium reserves. Cathode materials, which determine the energy density of PIBs, usually suffer from serious structural deformation during continuous K+ (de)intercalation. Therefore, proper structural‐design principles of cathode materials should be focused on to ensure high performance to promote the further development of PIBs.
Snap‐through bistability is often observed in nature (e.g., fast snapping to closure of Venus flytrap) and the life (e.g., bottle caps and hair clippers). Recently, harnessing bistability and ...multistability in different structures and soft materials has attracted growing interest for high‐performance soft actuators and soft robots. They have demonstrated broad and unique applications in high‐speed locomotion on land and under water, adaptive sensing and fast grasping, shape reconfiguration, electronics‐free controls with a single input, and logic computation. Here, an overview of integrating bistable and multistable structures with soft actuating materials for diverse soft actuators and soft/flexible robots is given. The mechanics‐guided structural design principles for five categories of basic bistable elements from 1D to 3D (i.e., constrained beams, curved plates, dome shells, compliant mechanisms of linkages with flexible hinges and deformable origami, and balloon structures) are first presented, alongside brief discussions of typical soft actuating materials (i.e., fluidic elastomers and stimuli‐responsive materials such as electro‐, photo‐, thermo‐, magnetic‐, and hydro‐responsive polymers). Following that, integrating these soft materials with each category of bistable elements for soft bistable and multistable actuators and their diverse robotic applications are discussed. To conclude, perspectives on the challenges and opportunities in this emerging field are considered.
Harnessing bistability and multistability for creating varieties of high‐performance soft robots has attracted increasing interest in soft robotics. This paper presents a comprehensive review of integrating representative bistable and multistable structures with soft materials under different actuations in soft actuators for diverse robotic functionalities, as well as, theoretical guidance on structural designs and materials selection for target robotic tasks.
•Describe lithium loss mechanism and lithium replenishment mechanism of various prelithiation strategies.•Summarize current structural design and interfacial modification strategies on prelithiation ...performance.•Outlook future perspectives and challenges of prelithiation technology in commercial applications.
Given the rising demand for high-energy–density devices in the commercial market, exploring new electrode materials is crucial for enhancing the energy density of lithium-ion batteries (LIBs). Novel electrode materials, which rely on conversion and alloy reactions, have attracted attention due to their high specific capacity and abundant resources. However, these materials often suffer from a large initial irreversible capacity and low-capacity retention, leading to significant active lithium consumption and a reduction in overall battery energy density. Consequently, a concise and efficient prelithiation technique is urgently needed to improve their electrochemical performance for commercial applications. Although various prelithiation methods have been developed, they predominantly remain experimental due to issues such as high reduction potential, poor prelithiation accuracy, and incompatibility with electrolytes, among others. From an industrial perspective, understanding the electrochemical reaction mechanisms and designing effective prelithiation technologies and electrode structures are vital for advanced lithium storage systems. This review first discusses the causes of active lithium loss and the electrochemical reaction mechanisms of different prelithiation methods. It summarizes the applications of advanced characterization methods in prelithiation technology. Then, various prelithiation strategies are reviewed and generalized according to the different components of LIBs. Additionally, the review examines the pathways for lithium replenishment and the recent developments in electrode structures within prelithiation strategies. Finally, the future perspectives and challenges of prelithiation technology in commercial applications are analyzed and projected.
Covalent organic frameworks (COFs) are a class of crystalline porous organic polymers with permanent porosity and highly ordered structures. Unlike other polymers, a significant feature of COFs is ...that they are structurally predesignable, synthetically controllable, and functionally manageable. In principle, the topological design diagram offers geometric guidance for the structural tiling of extended porous polygons, and the polycondensation reactions provide synthetic ways to construct the predesigned primary and high-order structures. Progress over the past decade in the chemistry of these two aspects undoubtedly established the base of the COF field. By virtue of the availability of organic units and the diversity of topologies and linkages, COFs have emerged as a new field of organic materials that offer a powerful molecular platform for complex structural design and tailor-made functional development. Here we target a comprehensive review of the COF field, provide a historic overview of the chemistry of the COF field, survey the advances in the topology design and synthetic reactions, illustrate the structural features and diversities, scrutinize the development and potential of various functions through elucidating structure–function correlations based on interactions with photons, electrons, holes, spins, ions, and molecules, discuss the key fundamental and challenging issues that need to be addressed, and predict the future directions from chemistry, physics, and materials perspectives.
The conceptual design decisions have the largest influence on a building project’s safety, value, and environmental impact; hence they are commonly assigned to a “senior engineer” to make use of ...his/her experience. However, the senior engineers can be biased towards solutions inside their area of expertise, which often prevents them from finding the best solutions among alternatives that must consider complex inter-related, and multi-disciplinary parameters. The engineering community could benefit from a rapid and high-quality decision-making method or tool to increase the speed and quality of its high-impact design choices. There are valuable studies in the literature exploiting Artificial Intelligence (AI) to improve the structural design process; however, most of them focus on the final design stage (e.g., Building Information Modeling), and the rest requires an existing project database (e.g., architectural drawings, already decided material types) to propose a small number of initial design alternatives. In this article, we present the development and validation of a genetic algorithm tool based on Non-dominated Sorted Genetic Algorithm II (NSGA-II) that can be used to analyse a wide range of safe, economical and low-CO2 options for the conceptual design of buildings. The design space starts from a design brief (with only the information about the site characteristics and project objectives). The solutions are explored with the material, grid size, floor type, lateral resistance, and foundation system variables. In a short computational time (< 2 min per run), users are provided with a Pareto graph of a large set of feasible solutions (in terms of cost, embodied CO2 emissions and free space) that an engineer would not be typically able to evaluate within a traditional conceptual design process. For future applications, the methodology presented in this paper is flexible to include more engineering materials (e.g., timber, masonry, structural glass), complex architectural forms and merge other disciplines in decision making (e.g., building physics construction management, fire safety).
Eight structural elements in biological materials are identified as the most common amongst a variety of animal taxa. These are proposed as a new paradigm in the field of biological materials science ...as they can serve as a toolbox for rationalizing the complex mechanical behavior of structural biological materials and for systematizing the development of bioinspired designs for structural applications. They are employed to improve the mechanical properties, namely strength, wear resistance, stiffness, flexibility, fracture toughness, and energy absorption of different biological materials for a variety of functions (e.g., body support, joint movement, impact protection, weight reduction). The structural elements identified are: fibrous, helical, gradient, layered, tubular, cellular, suture, and overlapping. For each of the structural design elements, critical design parameters are presented along with constitutive equations with a focus on mechanical properties. Additionally, example organisms from varying biological classes are presented for each case to display the wide variety of environments where each of these elements is present. Examples of current bioinspired materials are also introduced for each element.
A new paradigm in the field of biological materials science is proposed. Eight structural design elements are identified that serve as a toolbox for the rationalization of the complex mechanical behavior of structural biological materials and for systematizing the development of bioinspired designs for structural applications. These structures are: fibrous, helical, gradient, layered, tubular, cellular, suture, and overlapping.
Artificial intelligence is reshaping building design processes to be smarter and automated. Considering the increasingly wide application of shear wall systems in high-rise buildings and envisioning ...the massive benefit of automated structural design, this paper proposes a generative adversarial network (GAN)-based shear wall design method, which learns from existing shear wall design documents and then performs structural design intelligently and swiftly. To this end, structural design datasets were prepared via abstraction, semanticization, classification, and parameterization in terms of building height and seismic design category. The GAN model improved its shear wall design proficiency through adversarial training supported by data and hyper-parametric analytics. The performance of the trained GAN model was appraised against the metrics based on the confusion matrix and the intersection-over-union approach. Finally, case studies were conducted to evaluate the applicability, effectiveness, and appropriateness of the innovative GAN-based structural design method, indicating significant speed-up and comparable quality.
•An generative adversarial network-based automated structural design framework.•An open-access datasets of structural design drawings.•The datasets pre-processing method via pioneering abstraction, semanticization, classification, and parameterization.•Model validation approach based on confusion matrix and intersection-over-union metrics.
Microcosmic 3D hierarchical structural design has proved to be an effective strategy to obtain high‐performance microwave absorbers, although the treatments to low‐dimensional cells in monolithic ...framework are usually based on semiempirical rules. In this work, a hierarchical carbon fiber (CF)@MXene@MoS2 (CMM) core‐sheath synergistic structure with tunable and efficient microwave absorption (MA) properties is fabricated by introducing self‐assembled Ti3C2Tx MXene on the surface of CF and subsequent anchoring of MoS2. By the synergistic effects from the MXene sheath increasing the conductive loss and MoS2 at the outermost layer improving the impedance matching, the MA performance of CMM can be effectively regulated and optimized: the optimal reflection loss is −61.51 dB with a thickness of 3.5 mm and the maximum effective absorption bandwidth covers the whole Ku‐band with 7.6 GHz at 2.1 mm. Meanwhile, the whole X‐band absorption can also be achieved with specific MoS2 loading at an optimized thickness.
A hierarchical core‐sheath carbon fiber@MXene@MoS2 absorber is developed for tunable and efficient microwave absorption. Owing to its 1D MXene sheath and edge‐on MoS2 layers, the microwave attenuation capability and impedance matching are significantly improved. By controlling the load of MoS2, the effective absorption range can be tuned between the whole X‐band and Ku‐band.
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•Recent intensification strategies of SnO2-based photocatalysts are presented.•Band structure optimization, morphology control and composite photocatalysts are ...highlighted.•Photocatalytic applications and mechanisms are discussed.•Challenges and prospects of SnO2-based photocatalysts are proposed.
SnO2-based photocatalysts with excellent photocatalytic activity and promising prospects have widespread applications in the field of environmental science and energy. However, the photocatalytic efficiency of traditional SnO2 semiconductor with its inherent drawbacks is far from the actual requirements. Considerable works have been carried out to structural design, control morphology and construct composite systems to improve the photocatalytic performance. In this review, the latest developments and achievements of adjustment methods have been discussed in detail including doping, solid solution, stoichiometry alteration, ultrafine particles, fibers, thin structures, hierarchical and porous structures, crystal facet engineering, heterojunctions, SnO2/carbon materials, noble metal modified and dye sensitized SnO2. The photocatalytic applications of SnO2-based photocatalysts in organic pollutants degradation, water splitting, Cr(VI) reduction, CO2 reduction, air purification, and photocatalytic sterilization are summarized. Finally, the development prospects and challenges of SnO2-based photocatalysts are also proposed.
As in the case of supercapacitors, spinel NiCo2O4 shows the main drawbacks of objectionable pseudocapacitive mechanism, low-voltage polarization effect and confined ion-reaction dynamics, which ...result in constrained development, narrow work voltage, and low loading mass. Herein we combined two strategies to address these issues. The first one is to design the flower-like NiCo2O4 through Ostwald ripening of ultrathin Ni-Co layered double-hydroxide petals. And the second one is to balance the asymmetrical capacitance for further promoting capacitive behavior. With rationally designing the nano-/micro-structures, flower-like NiCo2O4 shows highly porous ultrathin petals interconnected with each other and massive interspaces between the petals. This unique microstructure endows flower-like NiCo2O4 with rapid electrolyte ions diffusion and mass transfer reaction. Consequently, the flower-like NiCo2O4 electrodes exhibit a high capacity of ∼350 C g−1 even the loading mass of up to 9 mg cm−2. More importantly, the hybrid supercapacitors, assembled with flower-like NiCo2O4 as cathode, deliver a high specific capacity of ∼85 F g−1 with capacitive ratio up to 74.3%, and a high working voltage of 1.55 V. The transformation of conventional battery-like materials into novel capacitive dominated materials through nano/micro-structural design and balance of asymmetrical capacitance is helpful to further understand the pseudocapacitive mechanism of transition metal oxides/sulfides and therefore will promote their practical application in next-generation of hybrid supercapacitors.
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