EcoMat最新文献

The high-voltage spinel LiNi_0.5Mn_1.5O₄ (LNMO) stands as a promising cathode material for lithium-ion batteries. However, the critical role of sol pH in modulating the crystal orientation and particle size of LNMO synthesized via sol–gel method remains insufficiently explored. Herein, this study focuses on investigating the influence of pH regulation on the crystal orientation, particle size, and electrochemical performance of LNMO. Through adjusting the pH value of the sol and calcination temperature of the resulting gel, LNMO with a truncated octahedral morphology is successfully tailored, characterized by (111)- and (100)-dominant exposed crystal planes and an appropriate amount of Mn⁴⁺/Mn³⁺ ratio. These features endow LNMO with lower Mn dissolution, less solid cathode-electrolyte interface (CEI) formation and faster Li⁺ transport kinetics, thereby resulting in superior specific capacity, cycling stability, and rate performance. Notably, the optimized LNMO delivers a high capacity of 123.0 mAh g⁻¹ at 0.5C, a favorable capacity retention of 85.2% over 200 cycles at 1C, and a fast Li⁺ diffusion coefficient on the order of 10⁻¹⁰ cm² s⁻¹. This work emphasizes the significance of sol pH as a key regulatory parameter for tailoring the microstructural and electrochemical properties of LNMO, offering a facile and effective strategy for performance optimization.

Moisture-induced degradation remains a significant obstacle to the industrial use of perovskite solar cells. This study systematically investigates and compares the stability and degradation mechanisms of MAPbI₃ perovskite films processed via traditional hot-plate annealing (HAF) and rapid microwave annealing (MAF) under high humidity. Morphological analyses show that microwave-annealed films have notably larger grain sizes (~848 nm) compared to those from hot-plate annealing (~247 nm). The larger grains and fewer grain boundaries in microwave-annealed films help reduce moisture infiltration, thus delaying degradation. X-ray diffraction analyses confirm that the formation of harmful PbI₂ and hydrated phases is slowed in microwave-annealed samples. Optical characterizations consistently demonstrate greater moisture resistance in microwave-annealed films, with less optical bleaching, fewer trap states, and better retention of carrier lifetime under high humidity. Performance tests show rapid efficiency losses in devices, with only 30% of the initial power conversion efficiency preserved in hot-plate annealed devices after 6 h at over 85% relative humidity. In contrast, microwave-annealed devices retain over 60% of their initial efficiency under the same conditions. This difference mainly results from significant reductions in photocurrent and open-circuit voltage. Long-term tests in low humidity environments further demonstrate the superior stability of microwave-annealed devices, highlighting their potential for practical solar cell applications. This research presents microwave annealing as a promising technique to enhance the stability of perovskite devices and facilitate their commercial deployment.

The rapid growth of the lithium-ion battery (LIB) market has led to a surge in cathode-scrap generation, emphasizing the urgent need for resource-efficient and environmentally responsible recycling strategies. While conventional recycling flowsheets effectively recover valuable metals, they typically involve multistep purification to remove Al originating from the cathode current collector. This process often poses technical and environmental challenges, such as managing large volumes of acidic wastewater and the continuous requirement for additional chemical reagents. Herein, a sustainable upcycling route is demonstrated that reutilizes the Al impurity as a functional dopant in Li[Ni_0.9Co_0.05Mn_0.05]_1−xAl_xO₂ (NCMA), eliminating the need for dedicated Al-removal and external Al sources. By applying mild-acid leaching to Li[Ni_0.6Co_0.1Mn_0.3]O₂ (NCM613) scrap, the residual Al content in the leachate is tuned and directly utilized during co-precipitation and calcination, completing a closed material loop. This approach not only reduces wastewater discharge and chemical consumption but also simplifies the overall recycling process. The resulting upcycled NCMA cathodes exhibit balanced electrochemical performance, retaining 65% of their initial capacity after 500 cycles while maintaining high-rate capability. These results highlight that impurity-derived Al, when properly managed, can serve as a sustainable dopant, transforming a contaminant into a resource. The developed process exemplifies a circular, low-waste strategy that aligns with next-generation green manufacturing and EU battery regulation frameworks by minimizing secondary waste streams and eliminating the need for virgin Al reagents.

Aqueous zinc-ion batteries are promising for flexible energy storage; however, water-related issues such as electrolyte decomposition, dendrite growth, and anode corrosion impede practical application. Although hydrogel electrolytes can suppress water activity and guide zinc-ion transport to inhibit dendrites, achieving high strength, high conductivity, and low temperature tolerance together remains challenging. Inspired by natural cryoprotection, a competitive interaction strategy using natural proline is present to enhance the polyvinyl alcohol (PVA)/ZnSO₄ hydrogel electrolyte. The hydrogel is physically crosslinked by PVA crystallites and stabilized by noncovalent interactions among PVA, Zn²⁺, and proline, showing 0.9 MPa tensile strength and 403% elongation. Proline's zwitterionic groups compete with water molecules in zinc-ion solvation, with a higher binding energy of 222.15 kcal/mol compared to 100.42 for water, enabling uniform Zn deposition and dendrite suppression. Zn||MnO₂ cells with this hydrogel retained 61% capacity after 200 cycles at 0.5 C, much better than the 32% with a liquid electrolyte. Proline also breaks the hydrogen bonding network of water, lowering the freezing point of the hydrogel to −27°C and maintaining 1.95 mS/cm conductivity at −20°C. The hydrogel allows flexible pouch cells to operate reliably under deformation and freezing conditions, demonstrating great potential for wearable energy storage.

Sensors that capture diverse environmental information are crucial in the elemental technology driving the Fourth Industrial Revolution. However, the trade-off between sensitivity and working range exhibited by conventional sensors results in limitations when the target stimuli deviate from their predesigned specifications. Thus, single sensors with adjustable performance characteristics must be developed to satisfy functionality requirements in diverse environments. In this study, a Tunable Usability-Nourished Electrostatic-based self-powered force sensor (TUNE sensor) is introduced to overcome the limitations of the fixed detection performance of a single sensor. The tunable sensing performance of the TUNE sensor is achieved via mechano-guided geometrical adaptation of its three-dimensional (3D) structure formed via mechanical buckling. Continuous and reversible shape changes in the 3D structure allow modulation of the stiffness of the TUNE sensor, resulting in tunable sensing performance (sensitivity of 0.53~1.08 nC/N and working range of 1.01~0.35 N). The effectiveness of the tunable sensing performance is demonstrated through its implementation in a reconfigurable electronic scale and robotic sensing. This mechano-guided geometrical adaptation strategy offers the potential for extending the use of sensors in multivariate environments and providing new opportunities for intelligent sensing systems in various applications.

This Highlight discusses a groundbreaking fiber-shaped fuel cell that uses swelling gel-encapsulated yarns to generate internal pressure. This strategy eliminates rigid components, enabling flexible, cuttable power sources for wearable electronics.

Anthropogenic carbon emissions pose a formidable challenge to contemporary society, driving severe global climate perturbations. In response, direct air capture (DAC) technologies have emerged as crucial tools for removing CO₂ from the atmosphere and curbing global warming. Non-thermal separation methods, particularly adsorption- and membrane-based processes utilizing porous materials, have significant advantages over traditional cryogenic and absorption systems. Porous materials, including zeolites, metal–organic frameworks (MOFs), covalent organic frameworks (COFs), hydrogen-bonded organic frameworks (HOFs), and molecular cages (MCs), are highly promising for advanced CO₂ capture, separation, and conversion due to their ordered and tunable pore architectures. Among these, MCs have emerged as a particularly promising class. MCs are composed of individually designed macromolecules and feature inherent cavities. They are soluble, readily regenerable, and amenable to precise chemical modifications. Over the past several years, MCs have demonstrated substantial potential for CO₂ capture, separation, and conversion, highlighting their value in addressing the global carbon challenge. This review provides a comprehensive examination of advancements in MCs, focusing particularly on their applications in the capture, separation, and conversion of CO₂. A forward-looking perspective on the future trajectories in this research field is provided. Concurrently, the current challenges requiring more in-depth investigation are discussed.

Skin injuries are common and frequently encountered health issues in daily life. Accelerating wound healing is therefore essential for alleviating discomfort and minimizing infection risks. Pulsed electric field (PEF) therapy shows promise for enhancing wound repair by modulating cellular responses and promoting growth factors activity, but conventional PEF systems are limited by their bulkiness, high cost, and poor adaptability to daily care. To address these limitations, we developed a self-powered electronic bandage based on a triboelectric nanogenerator (TENG). This bandage integrates high-resolution flexible interdigital electrodes and a moisture-adaptive layer. The design leverages the millisecond PEF generated by the TENG and the electric field amplification effect provided by the low-cost, high-precision interdigital electrode, thereby compensating for the inadequate electrical stimulation associated with traditional TENG devices in wearable medicine. Thus, this advancement facilitates the miniaturization of PEF devices for wound management. In vitro studies demonstrated its efficacy in enhancing cellular proliferation, while in vivo experiments using diabetic mouse models revealed accelerated wound closure, reduced inflammatory responses, and improved angiogenesis. By combining advanced device manufacturing with therapeutic electrostimulation, this electronic bandage offers a promising solution that combines biological compatibility, mechanical flexibility, and economic feasibility for daily wound care.

Lithium-sulfur (Li-S) batteries are promising candidates for high-energy storage; however, the high electrolyte uptake of porous S cathodes significantly limits their practical energy density. Although ultralight electrolytes (ULEs) can address this issue, they often suffer from low ionic conductivity, unstable interphases, and sluggish kinetics. This study presents a ULE design based on lithium bis(fluorosulfonyl)imide (LiFSI) salt, which simultaneously achieves a low density (0.89 g cm⁻³) and high Li⁺ conductivity (7.05 mS cm⁻¹). The LiFSI salt facilitates the formation of a LiF-rich solid electrolyte interphase on the Li metal anode, effectively suppressing polysulfide corrosion and enhancing cycle life. Furthermore, its high donor number improves polysulfide solubility, accelerating conversion kinetics and increasing capacity utilization. As a result, high-loading S cathodes (5 mg cm⁻²) deliver an initial capacity of 1180 mAh g⁻¹ and retain 70.63% of this capacity after 200 cycles. Pouch cells with the LiFSI-ULE exhibit a 34.5% higher energy density and a 133% longer cycle life compared to those with conventional electrolytes. This study successfully extends the application of LiFSI to Li-S batteries, offering a viable pathway toward long-cycling, high-energy-density energy storage.

Per- and polyfluoroalkyl substances (PFAS), notably perfluorooctanoic acid (PFOA), are persistent pollutants posing health risks via bioaccumulation and water mobility. While TiO₂ photocatalysis for PFOA degradation is well-reported, efficiency falters in dilute environments due to weak adsorption and rapid charge recombination. This study presents a novel hybrid approach with surface-modified TiO₂ designed to enhance PFOA adsorption while enabling simultaneous degradation. Fluorine-doped TiO₂ (F-TiO₂) was synthesized through cost-effective, one-step PVDF pyrolysis, promoting nanopores and hydrophobic interactions for PFOA enrichment alongside improved charge separation. UV–vis spectroscopy and UVC tests (254 nm, 1.59 mW/cm²) with sodium persulfate showed F-TiO₂ achieving ~92% PFOA removal at 700 mg/L (vs. ~58% for pristine TiO₂), with nine-fold faster kinetics (rate constant: 0.217 h⁻¹ vs. 0.024 h⁻¹; half-life: ~3.2 h vs. ~28 h). IC analysis confirmed partial PFOA mineralization, with ~25 ppm F⁻ detected after 16 h UV irradiation, indicating significant defluorination. Unlike noble-metal or graphene variants, F-TiO₂ exploits fluorine for adsorption-photocatalysis synergy, providing an economical, scalable PFAS remediation in low-concentration waters.