Sheng Bi

Microencapsulated phase change materials for battery thermal regulation require efficient heat transport during normal operation and thermal resistance during thermal runaway propagation. MXene modified inorganic phase change microcapsules (IPCM/MXene) were prepared by inverse emulsion interfacial sol−gel encapsulation using disodium hydrogen phosphate dodecahydrate as the core and SiO2 as the shell. Ti3C2Tx MXene bridged adjacent microcapsules, increasing thermal conductivity by 70.5% while retaining 93.7% of the melting enthalpy of unmodified IPCM. Under high temperature condition, thermal conductivity decreased by 54.6% following MXene oxidation and inorganic residue formation. In 18650 cell tests, IPCM/MXene reduced the peak temperature from 44.7 to 33.7 °C at 3C discharge and maintained stable cooling during repeated cycling. During thermal runaway propagation, the triggering of thermal runaway was delayed by 1899–1970 s, while the interval between the second and third cells increased from 122 to 193 s. These results establish a nonflammable microcapsule design for battery thermal management and safety protection.

Hydrogen (H2), known for its clean nature, high energy density, and renewability, is widely utilized in diverse fields including energy transport, the chemical industry, metallurgy, and aerospace. However, hydrogen poses a significant safety risk due to its flammability when its concentration in air exceeds 4%, making reliable leak detection essential. In this study, we present a highly responsive and efficient gasochromic hydrogen sensor designed to detect low-concentration hydrogen leaks through visible color changes. The sensor fabrication involves depositing a porous nanocolumnar amorphous WO3 layer onto glass particles, followed by the deposition of nanosized Pd particle, which serve as catalysts for H2 dissociation. To enhance durability and stability, the device is encapsulated with a PDMS coating. Comprehensive characterization of the structural, chemical, and optical properties of the WO3–Pd sensor demonstrates outstanding sensitivity. Notably, a visible color change can be detected within 3 s upon exposure to 1% H2 in air, with the color difference (ΔE) reaching up to 42 within 30 s and an accompanying transmittance change of 53%. Furthermore, the sensor exhibits stable and reliable cyclic performance, maintaining consistent responsiveness with no observable degradation (<5%) after 500 operational cycles. This innovative approach to gasochromic hydrogen sensing not only provides rapid and reliable leak detection but also ensures long-term stability and repeatability, making it a promising candidate for applications requiring high-sensitivity hydrogen monitoring.

3D metallic architectures are increasingly attractive for wireless communication systems, integrated metallic components, and multifunctional devices. However, reliably constructing geometrically complex, mechanically continuous, and compositionally diverse metallic structures remains challenging, particularly for multimetallic architectures, where differences in elastic modulus frequently led to interfacial delamination or structural failure. A dehydration‐driven self‐curling strategy that converts direct‐written metal‐hydrogel precursors into programmable 3D metallic architectures is introduced. By establishing a through‐thickness asymmetry in water content, initially planar hydrogel films undergo deterministic shape morphing into intricately curved 3D geometries, achieving bending curvatures up to 0.45 mm ⁻¹ , volumetric shrinkage of 56.5%, and post‐conversion dimensional fidelities exceeding 90%. Subsequent calcination and atmosphere‐controlled reduction yield dense metallic structures. This fabrication route decouples geometric programming from material conversion, enabling high‐fidelity shape retention across multiple metal systems. Demonstrations include programmable self‐curling Cu/Ni composite tubes that maintain interfacial integrity during high‐temperature treatment and operate effectively as radio frequency antennas, exhibiting resonances at 1.575 and 2.4 GHz with return losses below −20 dB. Overall, this work provides a practical fabrication strategy for programmable multimetallic 3D architectures through dehydration‐guided morphing and subsequent thermal conversion.

The global pandemic of aerosol- and droplet-borne infectious diseases has highlighted the urgent need for a new generation of protective masks with efficient active inactivation capabilities. However, traditional protective masks rely on passive physical barriers and do not provide long-lasting and efficient protection. Existing sterilization masks rely on external conditions such as power, photocatalysis, and heating, which reduces the usefulness of the masks. In this work, we present a novel self-powered multiple sterilization mask (SMSM) that integrates pulsed electric field sterilization and chemical sterilization, achieving 99.9% pathogen inactivation. The Ag-PP/ePTFE functional layer of the mask is based on an expanded polytetrafluoroethylene (ePTFE) film with a coating of silver nanoparticles (AgNPs) deposited on one side and polypropylene (PP) fibers attached to the other. Driven intermittently by human respiration, Ag-PP/ePTFE interacts with the midlayer meltblown fabric to form a vertical contact-separated triboelectric nanogenerator that generates a pulsed electric field. The field disrupts bacterial cell membranes through electroporation while activating multiple chemical reactions to produce antimicrobial silver ions (Ag⁺) and hydroxyl radicals (·OH). SMSM provides multiple active sterilization mechanisms independent of external conditions. This work provides a sustainable and effective solution for the next generation of protective masks.

All-solid-state laser printing (ASLP) deposits charged solid powders onto flexible substrates via solvent-free electrostatic attraction, enabling scalable fabrication of high-performance optoelectronic devices.

Grain boundaries are among the most influential structural features that control the charge transport in polycrystalline organic semiconductors. Acting as both charge trapping sites and electrostatic barriers, they disrupt molecular packing and introduce energetic disorder, thereby limiting carrier mobility, increasing threshold voltage, and degrading the stability of organic thin-film transistors (OTFTs). This review presents a detailed discussion of grain boundary formation, their impact on charge transport, and experimental strategies for engineering their structure and distribution across several high-mobility small-molecule semiconductors, including pentacene, TIPS pentacene, diF-TES-ADT, and rubrene. We explore grain boundary engineering approaches through solvent design, polymer additives, and external alignment methods that modulate crystallization dynamics and domain morphology. Then various case studies are discussed to demonstrate that optimized processing can yield larger, well-aligned grains with reduced boundary effects, leading to great mobility enhancements and improved device stability. By offering insights from structural characterization, device physics, and materials processing, this review outlines key directions for grain boundary control, which is essential for advancing the performance and stability of organic electronic devices.