EcoMat最新文献

Based on the coupling effects of contact electrification and electrostatic induction, a triboelectric nanogenerator (TENG) can convert mechanical energy into electric power, which is at the cutting edge of alternative energy technology. Although a considerable number of TENGs with different configurations have been designed, some of them however, which only depend on the electrostatic induction effect have not received enough attention. Here, a non-contact TENG model consists of copper rings and charged dielectric sphere is presented, which is aimed at exploring the working process of TENGs caused by electrostatic induction. Two classical models, including vertical and horizontal double copper rings models are also proposed. Relevant advanced and accurate models of TENGs have been established through the finite element method. We anticipate that the constructed model and theoretical analysis are helpful for the design of non-contact model TENGs with complicated geometric construction, and expand their applications in various fields.

Sodium-ion battery (SIB) is considered as a revolutionary technology toward large-scale energy storage applications. Developing cost-effective cathode material as well as economical synthesis procedure is a key challenge for its commercialization. Herein, we develop a facile and economic strategy to simultaneously remove rust from the surface of carbon steel and achieve porous and hollow spherical Na₄Fe₃(PO₄)₂P₂O₇/C (HS-NFPP/C). Benefiting from the desirable structure that fastens the electronic/ionic transportation and effectively accommodates the volume expansion/contraction during discharge/charge process, the as-prepared cathode exhibits outstanding rate capability and ultralong cycle life. An extraordinarily high-power density of 32.3 kW kg⁻¹ with an ultrahigh capacity retention of 89.7% after 10 000 cycles are achieved. More significantly, the 3 Ah HC||HS-NFPP/C full battery manifests impressive cycling stability. Therefore, this work provides an economical and sustainable approach for the massive production of high-performance Na₄Fe₃(PO₄)₂P₂O₇ cathode, which can be potentially commercialized toward SIB applications.

As a group of emerging liquid-like thermoelectric materials for waste heat recovery into useful energy, di-chalcogenides Cu₂(S, Se, Te) have been considered as superionic thermoelectric materials. Due to their highly disordered degree of Cu-ion in the crystal lattice, Cu₂(S, Se, Te) compounds can exhibit ultralow thermal conductivity, and in the meantime, their rigid sublattice can decently maintain the electrical performance, making them distinct from other state-of-the-art thermoelectric materials. This review summarizes the well-designed strategies to realize the impressive performance in thermoelectric materials and their modules by linking the adopted approaches such as defect engineering, interfaces, nano-porous inclusions, thin films, dislocations, nano-inclusions, and polycrystalline bulks etc., with the moderate design of the device. Some recent reports are selected to outline the fundamentals, underlined challenges, outlooks, and future development of Cu₂(S, Se, Te) liquid-like thermoelectric materials. We expect that this review covers the needs of future researchers in choosing some potential materials to explore thermoelectricity and other efficient energy conversion technologies.

Dynamic covalent chemistry offers a solution to tackle the recycling issue of epoxy resins (EPs) and their carbon fiber-reinforced composites; however, the vulnerability to creep associated with the inflammable nature of the EPs are the key obstacles for their applications. Herein, we propose a feasible and facile strategy to overcome these obstacles by incorporating phosphorus-influenced Diels-Alder (DA) chemistry to construct dynamic epoxy networks. In the strategy, the electron-withdrawing phosphonate in the dienophile maleimide greatly promotes the thermal stability of the DA reaction, exhibiting excellent creep resistance, repairability, and malleability; while its flame-retardant activity improves the fire safety of the resultant thermosets. Meanwhile, nondestructive recycling of carbon fiber is achieved. The ease with which EP and its composites can be manufactured, used, recycled and re-used–without losing service performance–points to new orientation in sustainable composites.

Solar-driven interfacial evaporation is a sustainable and economical technology for freshwater generation. Structural design of photothermal material is an effective strategy to improve the evaporation performance but is usually bothered by complicated processes and non-adjustability. Herein, magnetic nanoparticles assembled photothermal evaporator was developed, which showed an adjustable spinal array surface under uniform magnetic field induction. By regulating position in the magnetic field, the desirable surface structures could be uniform at relatively low load density of magnetic nanoparticles to improve light absorption via multiple reflections. Magnetic field induced evaporator could accelerate evaporation to over 1.39 kg m⁻² h⁻¹ under 1-sun illumination, which was 2.8 times that of natural evaporation. After coated by carbon layer, magnetic nanoparticles could overcome the oxidation to realize stable evaporation in long-term desalination. The facile strategy to optimize the surface structure via magnetic field is appropriate for various fields with special requirements on surface structure.

Piezoelectric polymer fibers offer a fundamental element in intelligent fabrics with their shape adaptability and energy-conversion capability for wearable activity and health monitoring applications. Nonetheless, realizing high-performance smart polymer fibers faces a technical challenge due to the relatively low piezoelectric performance. Here, we demonstrate high-performance piezoelectric yarns simultaneously equipped with structural robustness and mechanical flexibility. The key to substantially enhanced piezoelectric performance is promoting the electroactive β-phase formation during electrospinning via adding an adequate amount of barium titanate (BaTiO₃) nanoparticles into the poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)). When transformed into a yarn structure by twisting the electrospun mats, the BaTiO₃-doped P(VDF-TrFE) fibers become mechanically strengthened with significantly improved elastic modulus and ductility. Owing to the tailored convolution neural network algorithms architected for classification, the as-developed BaTiO₃-doped piezo-yarn device woven into a cotton fabric exhibits monitoring and identifying capabilities for body signals during seven human motion activities with a high accuracy of 99.6%.

In this study, we demonstrate that a digital colorimetric sensor platform can transform a conventional energy system, such as gas-insulated switchgear (GIS) into a smart green energy system. Our sensor platform consists of a colorimetric sensor film (CSF), an array of silicon photodiodes, and a low-power-driven fiber optical photodiode with a wireless communication protocol integrated into an information network. The photodiode measures the transmitted light of the color-variable CSF when exposed to sulfur dioxide (SO₂) gas, a decomposition by-product of the sulfur hexafluoride (SF₆) gas in GIS. We report the electrical photocurrent measurement through the CSF can measure the concentration of SO₂ gas via remote and real-time monitoring and shows a comparable behavior to UV–Vis absorption measurement. The limit of detection of the sensor, 0.78 ppm is sufficient to analyze the GIS insulation deterioration allowing green energy systems.

Developing redox electrolytes with high thermopower is the key to making efficient thermogalvanic batteries for harvesting low-grade heat. This work applies molecular dynamics simulations to predict the thermopower (i.e. thermogalvanic temperature coefficient) $��\alpha �$ of the redox pairs Fe(CN)₆³⁻/Fe(CN)₆⁴⁻ and Fe³⁺/Fe²⁺, showing excellent agreement with experimental values. We showed that $��\alpha �$ of the Fe³⁺/Fe²⁺ redox pair can be increased from 1.7$��\pm �$0.4 mV/K to 3.8$��\pm �$0.5 mV/K with the increased acetone to water fraction. We discovered a significant change in the variance of solvent dipole orientation between Fe³⁺ and Fe²⁺, which can serve as a microscopic indicator for large $��\alpha �$. In mixed acetone-water solvent, $��\alpha �$ of Fe³⁺/Fe²⁺ showed a rapid increase at high acetone fractions, due to the intercalation of acetone molecules into the first solvation shell of the Fe²⁺ at high acetone fractions. Our discovery provides insights into how solvation shell order can be engineered to develop electrolytes with high $��\alpha �$.

Sulfide solid electrolyte (SSE)-based all-solid-state Li batteries (ASSLBs) can overcome the problems of low energy density and safety concern of current Li-ion batteries. However, the practical application of SSE-based ASSLBs is suffered from several problems, especially interfacial issues between Li metal anode (LMA) and SSEs. Therefore, in this study, the problems of the LMA–SSE interface and their corresponding solutions are reviewed. First, the interfacial problems are summarized, namely the side reactions of SSEs, the Li dendrite growth, and poor contact between the electrode and electrolyte. Second, the available strategies to improve the robustness of the interface are discussed, including the protection of the LMA, substitution of the LMA, and modification of SSEs. Third, the characterization methods used to analyze the morphological and compositional evolution of the interface during cycling are introduced. Finally, the limitations and future research directions are proposed.

Including the transpiration of leaves, water evaporation from solar irradiation is a universal phenomenon in nature. Currently, solar vapor generation allows clean water to be obtained from various waterbodies. Since water is transported through porous structures and evaporates on their surfaces, the properties of the nano-micro structure, especially the surfaces are significantly important. For instance, the surface energy, determined by the localized atomic arrangement, can modify the interactions between water and the substrate. Moreover, the construction of a three-dimensional hierarchical structure can efficiently enlarge the surface area, and the provided channels play a vital role in mass transfer. In this review, we summarize recent research on the structural regulation in tuning the sequential steps in photo-vapor generation. We hope this review can provide a rational and systemic basis for the development of advanced solar vapor generating materials, especially from the view of surface engineering.