Multifunctional materials are in high demand for practical engineering applications. Owing to the ubiquitous noise and impact energy hazards in many settings, traditional materials and conventionally designed metamaterials are incapable of preventing these types of hazard simultaneously. Herein, we report a new paradigm, via a decoupled approach, in the design of acousto-mechanical multifunctional metamaterials. We leverage the morphology of a Helmholtz resonator, such that the sound-absorbing and mechanical components are designed independently. For sound absorption, we adopt a coherent coupling design for a favorable resonant response, while for the mechanical response, we adopt customized struts. We then demonstrate our concept via 3D printing. Experimentally measured remarkable broadband absorption in the practical low-frequency range (<1.0 kHz) is achieved. Absorption mechanisms are attributed to viscous and thermal boundary dissipation. Compression tests also reveal that the metamaterials are highly deformation resilient with a recovery of up to 98%, owing to both the lattice structure design and the viscoelastic behavior of the base material. Through this decoupled design, we further demonstrate the potential of our metamaterials in customizable absorption, strength, pseudo-reusability, and impact resistance. The proposed design paradigm broadens the horizon for the design of multifunctional materials, offering an impetus to their exploration for practical applications.

Multifunctional sound-absorbing and mechanical metamaterials via a decoupled mechanism design approach.

Thermal runaway (TR) failures of large-format lithium-ion battery systems related to fires and explosions have become a growing concern. Here, we design a smart ceramic-hydrogel nanocomposite that provides integrated thermal management, cooling, and fire insulation functionalities and enables full-lifecycle security. The glass-ceramic nanobelt sponges exhibit high mechanical flexibility with 80% reversible compressibility and high fatigue resistance, which can firmly couple with the polymer-nanoparticle hydrogels and form thermal-switchable nanocomposites. In the operating mode, the high enthalpy of the nanocomposites enables efficient thermal management, thereby preventing local temperature spikes and overheating under extremely fast charging conditions. In the case of mechanical or thermal abuse, the stored water can be immediately released, leaving behind a highly flexible ceramic matrix with low thermal conductivity (42 mW m-1 K-1 at 200 °C) and high-temperature resistance (up to 1300 °C), thus effectively cooling the TR battery and alleviating the devastating TR propagation. The versatility, self-adaptivity, environmental friendliness, and manufacturing scalability make this material highly attractive for practical safety assurance applications.

Thermal-Switchable, Trifunctional Ceramic-Hydrogel Nanocomposites Enable Full-Lifecycle Security in Practical Battery Systems.

Traditional ceramic materials are suboptimal for use in complex environments because of their brittleness and sensitivity to flaws. As such, developing flexible and elastic ceramic materials is extremely urgent in frontier domains where high‐frequency vibration or high‐intensity bending environments are inevitable. Fibrillation of ceramic materials is an effective way for the transition of brittleness to flexibility and elasticity, due to its ability to absorb and dissipate stresses through large axial deformations. Here, a comprehensive review of the newly emerging flexible and elastic ceramic fiber materials is presented, starting from an introduction to the fundamental concept, followed by an in‐depth analysis of the relationship between their microstructures and mechanical behaviors, laying emphasis on the toughening mechanism of both individual fibers and fiber assemblies. Finally, current challenges and future development are demonstrated. It is expected that this review may provide meaningful guidance for the advancement of ceramic fiber materials toward better performance and brighter prospects.

The Rising of Flexible and Elastic Ceramic Fiber Materials: Fundamental Concept, Design Principle, and Toughening Mechanism

Carbon Layer Encapsulation Strategy for Designing Multifunctional Core-Shell Nanorod Aerogels as High-Temperature Thermal Superinsulators

Poly(p-phenylene terephthalamide) (PPTA) is one kind of lyotropic liquid crystal polymer. Kevlar fibers performed from PPTA are widely used in many fields due to their superior mechanical properties resulting from their highly oriented macromolecular structure. However, the “infusible and insoluble” characteristic of PPTA gives rise to its poor processability, which limits its scope of application. The strong interactions and orientation characteristic of aromatic amide segments make PPTA attractive in the field of self-assembly. Chemical derivation has proved an effective way to modify the molecular structure of PPTA to improve its solubility and amphiphilicity, which resulted in different liquid crystal behaviors or supramolecular aggregates, but the modification of PPTA is usually complex and difficult. Alternatively, higher-order all-PPTA structures have also been realized through the controllable hierarchical self-assembly of PPTA from the polymerization process to the formation of macroscopic products. This review briefly summarizes the self-assembly methods of PPTA-based materials in recent years, and focuses on the polymerization-induced PPTA nanofibers which can be further fabricated into different macroscopic architectures when other self-assembly methods are combined. This monomer-started hierarchical self-assembly strategy evokes the feasible processing of PPTA, and enriches the diversity of product, which is expected to be expanded to other liquid crystal polymers.

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Recent Advances in Self-Assembly and Application of Para-Aramids

Nanograin–glass dual-phasic, elasto-flexible, fatigue-tolerant, and heat-insulating ceramic sponges at large scales

Nitrogen-doped carbon dots with bright fluorescence for highly sensitive detection of Fe3+ in environmental waters.

Abstract Prelithiation can boost the performance of lithium-ion batteries (LIBs). A cost-effective prelithiation strategy with high quality and high industrial compatibility is urgently required. Herein we developed a roll-to-roll electrodeposition and transfer-printing system for continuous prelithiation of LIB anodes. By roll-to-roll calendering, pre-manufactured anodes could be fully transfer-printed onto electrodeposited lithium metal. The interface separation and adhesion during transfer printing were related to interfacial shear and compressive stress, respectively. With the facile transfer-printing prelithiation, high initial Coulombic efficiencies of 99.99% and 99.05% were achieved in graphite and silicon/carbon composite electrode half cells, respectively. The initial Coulombic efficiencies and energy densities in full cells were observed to be significantly improved with the prelithiated electrodes. The roll-to-roll transfer printing provides a high-performance, controllable, scalable and industry-adaptable prelithiation in LIBs. 

/pdf/roll-to-roll-prelithiation-of-lithium-ion-battery-anodes-by-1rb6ht23.pdf

Roll-to-roll prelithiation of lithium-ion battery anodes by transfer printing

By imitating natural water circulation, artificial water generation processes can produce clean water by utilizing readily available and inexhaustible solar energy. Such a process can address the current global crises related to both energy and water shortages, and expand currently available water resources from rivers, ground water and ice to seawater, brackish water and atmospheric humidity. Among the many materials used for water generation, aerogels offer a great potential due to the inherent combination of three-dimensional, monolithic structure and porous, interconnected network. In this article, we review aerogel-based water generation from brine and atmospheric water. The unique features of aerogels are elucidated from the viewpoint of photo-thermal conversion and water transport. These two components are necessary to achieve efficient solar-driven water production systems. In addition to describing the material specifications, this paper reviews a diversity of structural designs that aim to improve the evaporation performance, including the assembly strategy of light absorption and thermal insulation layers, the reduction of evaporation enthalpy, and the salt-rejection control, as well as Marangoni effect. After evaluating different types of solar-powered water utilization technologies, the paper ends with the challenges for the commercialization and widespread use of aerogel-based water production systems: their disconnect from the current aerogel industry, high production cost and weak mechanical properties, and a lack of standardized performance testing, as well as our future perspective for their application opportunities. 

Aerogel-based solar-powered water production from atmosphere and ocean: A review

Accurate quantum reactive calculations for the reaction Li + HD + ( v = 0 , 1 , j = 0 ) have been performed on the potential energy surface of Martinazzo et al. [J. Chem. Phys. 119 (21), 11241 (200...

A quantum mechanical study of the astrophysically important reaction Li + HD+ (v = 0,1, j = 0): the effect of reagent vibrational and translational excitation on the angular distributions of LiH and LiD

Hui Wu

Papers

Nanograin–glass dual-phasic, elasto-flexible, fatigue-tolerant, and heat-insulating ceramic sponges at large scales

Nitrogen-doped carbon dots with bright fluorescence for highly sensitive detection of Fe3+ in environmental waters.

Roll-to-roll prelithiation of lithium-ion battery anodes by transfer printing

Aerogel-based solar-powered water production from atmosphere and ocean: A review

A quantum mechanical study of the astrophysically important reaction Li + HD+ (v = 0,1, j = 0): the effect of reagent vibrational and translational excitation on the angular distributions of LiH and LiD