Synthesis of Phosphorus–Sulfur-Containing Polyols for Intrinsic Flame Retardant Flexible Polyurethane Foams with Enhanced Mechanical Properties

The development and preparation of intrinsic flexible polyurethane foam (FPUF) with low-load flame retardancy and high mechanical properties are challenging. Herein, a reactive flame retardant, poly(ethylene methylphosphonothioate) (PEMPT), was synthesized by the polycondensation of methylphosphonothioic dichloride and ethylene glycol. Subsequently, PEMPT was chemically bound to the FPUF chain. When the PEMPT content was 2.5 wt % polyols, the FPUFs exhibited self-extinguishing properties in less than 3 s after removing the igniter and passed the TB 117-2000 vertical burning test. Furthermore, the flame retardant FPUF with only 10 wt % PEMPT loading (FPUF10) showed an oxygen index value of 23.5%. Also, its peak heat release and total heat release rates were reduced by 25.8 and 24.0%, respectively. Concurrently, the incorporation of PEMPT improved the compressive and reversible properties of the foams. These results indicate that PEMPT is a promising flame retardant to endow FPUF with excellent flame retardancy and mechanical properties

Built-in Electric Field in Quasi-2D CsPbI₃ Perovskites Using High-Polarized Zwitterionic Spacer for Enhanced Charge Separation/Transport

Two-dimensional (2D) halide perovskites are promising candidates for the fabrication of stable and high-efficiency solar cells. However, the low power conversion efficiency (PCE) of cell devices using 2D perovskites is attributed to reduced charge transport caused by poor organic barrier conductivity. In this study, we propose the use of a high-polarized organic zwitterionic spacer, p-aminobenzoic acid (PABA), to construct novel quasi-2D perovskite structures with enhanced self-driven charge separation and transfer. The NH3+ and COO– groups in PABA generate an aligned electric field, promoting carrier separation and aggregation on the opposite edges of the inorganic layer. This enables efficient in-plane transportation along the inorganic layer. Additionally, PABA intercalated quasi-2D perovskite exhibits improved stability compared with counterparts with diamine cation spacers due to the strong interaction between −COO– and inorganic layers. Our findings suggest that high-polarized organic zwitterionic spacers, with NH3+ and COO– functionality, hold promise for stable and efficient quasi-2D perovskite solar cells

Computational Discovery of the Qualitative Electronegativity–Wettability Relationship in High-Temperature Ceramics-Supported TiAl Alloys

The inevitable interaction between high-temperature ceramics (HTCs) and molten TiAl alloys during the casting process tends to cause the increased oxygen concentration, fracture, and embrittlement within TiAl alloys, and the interaction is closely related to wettability. Herein, the underlying mechanism of wettability (i.e., contact angle) between HTCs and molten TiAl alloys is systematically investigated by molecular dynamics (MD) simulations. Taking the interaction between the common adopted crucible (i.e., BaZrO3, Y2O3, ZrO2, and Al2O3) and molten TiAl alloys, for example, the calculated contact angles between γ-TiAl and HTCs decrease in the sequence of BaZrO3, Y2O3, ZrO2, and Al2O3 and with the Ti content of TiAl alloys increasing. This is in agreement with the experimental results, verifying the feasibility of MD simulations. In addition, based on MD simulations, the electronegativity of metal elements within HTCs decreases in the order of Al2O3, ZrO2, Y2O3, and BaZrO3, which further discloses the relationship between electronegativity and wettability, i.e., smaller electronegativity of metal elements leads to worse wettability of HTCs. This might push forward the design of HTCs with better stability, such as BaZrO3 doped by Hf, Y, lanthanide, or actinide elements and BaHfO3

Energy Level Matching and Band Edge Reconfiguration for Enhanced Charge Transport in Dion–Jacobson 3D/2D Perovskite Heterojunctions

Generally, the 2D CsPbI3 layer capping on 3D counterparts has been considered as an effective strategy for both enhancing photovoltaic efficiency and stability. However, the intrinsically poor out-of-plane charge transport through the 2D layer remarkably hinders the overall performance of solar devices. To overcome such a challenge, we report the rationally designed 3D-CsPbI3/2D-(PYn)PbI4 (n = 1–4) heterojunctions with desirable energy level matching. It is evidenced that the valence band (VB) edge reconfiguration would occur with the increase of n, accompanied by the VB maximum (VBM) of the 2D component moving down from the higher level above that of the 3D component to the underneath. Consequently, the as-constructed 3D/2D-(PYn)PbI4 (n = 1, 2) heterojunctions exhibit optimal energy level matching, with accelerated transport of holes from 3D to 2D component and limited backflow of electrons. These findings might provide some meaningful insights on the energy level matching in 3D/2D perovskite heterojunctions

Robust Ionics Reinforced Fiber As Implantable Sensor for Early Operando Monitoring Cell Thermal Safety of Commercial Lithium-Ion Batteries

Commercial batteries have been largely applied in mobile electronics, electric vehicles, and scalable energy storage systems. However, thermal runaway of batteries still obstructs the reliability of electric equipment. Considering this, building upon recent investigations of energy thermal safety, commercially available organogel fiber-based implantable sensors have been developed through 3D printing technology for first operando implantable monitoring of cell temperature. The printed fibers present excellent reliability and superelasticity because of internal supramolecular cross-linking. High temperature sensitivity (−39.84% °C–1/–1.557% °C–1) within a wide range (−15 to 80 °C) is achieved, and the corresponding mechanism is clarified based on in situ temperature-dependent Raman technology. Furthermore, taking the pouch cell as an example, combined with finite element analysis, the real-time observation system of cell temperature is successfully demonstrated through an implanted sensor with wireless Bluetooth transmission. This enlightening approach paves the way for achieving safety monitoring and smart warnings for various electric equipment

Robust Ionics Reinforced Fiber As Implantable Sensor for Early Operando Monitoring Cell Thermal Safety of Commercial Lithium-Ion Batteries

Commercial batteries have been largely applied in mobile electronics, electric vehicles, and scalable energy storage systems. However, thermal runaway of batteries still obstructs the reliability of electric equipment. Considering this, building upon recent investigations of energy thermal safety, commercially available organogel fiber-based implantable sensors have been developed through 3D printing technology for first operando implantable monitoring of cell temperature. The printed fibers present excellent reliability and superelasticity because of internal supramolecular cross-linking. High temperature sensitivity (−39.84% °C–1/–1.557% °C–1) within a wide range (−15 to 80 °C) is achieved, and the corresponding mechanism is clarified based on in situ temperature-dependent Raman technology. Furthermore, taking the pouch cell as an example, combined with finite element analysis, the real-time observation system of cell temperature is successfully demonstrated through an implanted sensor with wireless Bluetooth transmission. This enlightening approach paves the way for achieving safety monitoring and smart warnings for various electric equipment

Robust Ionics Reinforced Fiber As Implantable Sensor for Early Operando Monitoring Cell Thermal Safety of Commercial Lithium-Ion Batteries

Commercial batteries have been largely applied in mobile electronics, electric vehicles, and scalable energy storage systems. However, thermal runaway of batteries still obstructs the reliability of electric equipment. Considering this, building upon recent investigations of energy thermal safety, commercially available organogel fiber-based implantable sensors have been developed through 3D printing technology for first operando implantable monitoring of cell temperature. The printed fibers present excellent reliability and superelasticity because of internal supramolecular cross-linking. High temperature sensitivity (−39.84% °C–1/–1.557% °C–1) within a wide range (−15 to 80 °C) is achieved, and the corresponding mechanism is clarified based on in situ temperature-dependent Raman technology. Furthermore, taking the pouch cell as an example, combined with finite element analysis, the real-time observation system of cell temperature is successfully demonstrated through an implanted sensor with wireless Bluetooth transmission. This enlightening approach paves the way for achieving safety monitoring and smart warnings for various electric equipment

Robust Ionics Reinforced Fiber As Implantable Sensor for Early Operando Monitoring Cell Thermal Safety of Commercial Lithium-Ion Batteries

Commercial batteries have been largely applied in mobile electronics, electric vehicles, and scalable energy storage systems. However, thermal runaway of batteries still obstructs the reliability of electric equipment. Considering this, building upon recent investigations of energy thermal safety, commercially available organogel fiber-based implantable sensors have been developed through 3D printing technology for first operando implantable monitoring of cell temperature. The printed fibers present excellent reliability and superelasticity because of internal supramolecular cross-linking. High temperature sensitivity (−39.84% °C–1/–1.557% °C–1) within a wide range (−15 to 80 °C) is achieved, and the corresponding mechanism is clarified based on in situ temperature-dependent Raman technology. Furthermore, taking the pouch cell as an example, combined with finite element analysis, the real-time observation system of cell temperature is successfully demonstrated through an implanted sensor with wireless Bluetooth transmission. This enlightening approach paves the way for achieving safety monitoring and smart warnings for various electric equipment

Robust Ionics Reinforced Fiber As Implantable Sensor for Early Operando Monitoring Cell Thermal Safety of Commercial Lithium-Ion Batteries

Commercial batteries have been largely applied in mobile electronics, electric vehicles, and scalable energy storage systems. However, thermal runaway of batteries still obstructs the reliability of electric equipment. Considering this, building upon recent investigations of energy thermal safety, commercially available organogel fiber-based implantable sensors have been developed through 3D printing technology for first operando implantable monitoring of cell temperature. The printed fibers present excellent reliability and superelasticity because of internal supramolecular cross-linking. High temperature sensitivity (−39.84% °C–1/–1.557% °C–1) within a wide range (−15 to 80 °C) is achieved, and the corresponding mechanism is clarified based on in situ temperature-dependent Raman technology. Furthermore, taking the pouch cell as an example, combined with finite element analysis, the real-time observation system of cell temperature is successfully demonstrated through an implanted sensor with wireless Bluetooth transmission. This enlightening approach paves the way for achieving safety monitoring and smart warnings for various electric equipment