EcoMat最新文献

Deformable lithium-ion batteries (LIBs) can serve as the main power sources for flexible and wearable electronics owing to their high energy capacity, reliability, and durability. The pivotal role of cathodes in LIB performance necessitates the development of mechanically free-standing and stretchable cathodes. This study demonstrates a promising strategy to generate deformable cathodes with electrical conductivity by forming 3D interconnected elastomeric networks. Beginning with a physically crosslinked polymer network using poly(vinylidene fluoride-co-hexafluoropropylene) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]), subsequent exchange with a 1 M LiPF₆ electrolyte imparts elastic characteristics to the cathodes. The resulting LiFePO₄ composite electrodes maintained their resistance under 500 consecutive bending cycles at an extremely small bending radius of 1.8 mm and showed high discharge capacity of 158 mAh g⁻¹ with stable potential plateaus in charging and discharging curves. Moreover, flexible cells utilizing the composite electrodes exhibited superior operational stability under rolling, bending, and folding deformations.

Anion exchange is an effective strategy to regulate the composition and optoelectronic properties of perovskite quantum dots (PQDs). Though promising, it is more desirable to synthesize PQDs to avoid the decrease of photoluminescence quantum yield (PLQY). Herein, we developed a ligand mediated anion exchange approach, in which the phase transition from CsPbBr₃ QDs to CsPbI₃ QDs was observed with the introduction of N-Acetyl-l-cysteine (NAC) and 1,3-dimethylimidazolium iodide (DMII) aqueous solution in CsPbBr₃ QDs solution. NAC is expected to create more halogen vacancies in CsPbBr₃ QDs, which provides sufficient adsorption sites for I⁻ ions, resulting in accelerating the anion exchange rate in the process of DMII incorporation. Benefiting from the synergistic ligand mediated anion exchange, high PLQY of 97% and remarkable stability of CsPbI₃ QDs are obtained. Furthermore, a white light-emitting diode (WLED) with a lumen efficiency (LE) of 116.82 lm/W is constructed, showing remarkable stability under continuous operation.

Perovskite solar cells offer a promising future for next-generation photovoltaics owing to numerous advantages such as high efficiency and ease of processing. However, two significant challenges, air stability, and manufacturing costs, hamper their commercialization. This study proposes a solution to these issues by introducing a floating catalyst-based carbon nanotube (CNT) electrode into all-inorganic perovskite solar cells for the first time. The use of CNT eliminates the need for metal electrodes, which are primarily responsible for high fabrication costs and device instability. The nanohybrid film formed by combining hydrophobic CNT with polymeric hole-transporting materials acted as an efficient charge collector and provided moisture protection. Remarkably, the metal-electrode-free CNT-based all-inorganic perovskite solar cells demonstrated outstanding stability, maintaining their efficiency for over 4000 h without encapsulation in air. These cells achieved a retention efficiency of 13.8%, which is notable for all-inorganic perovskites, and they also exhibit high transparency in both the visible and infrared regions. The obtained efficiency was the highest for semi-transparent all-inorganic perovskite solar cells. Building on this, a four-terminal tandem device using a low-band perovskite solar cell achieved a power conversion efficiency of 21.1%. These CNT electrodes set new benchmarks for the potential of perovskite solar cells with groundbreaking device stability and tandem applicability, demonstrating a step toward industrial applications.

Value-added conversion of lignocellulose is a sustainable approach. Photo-refining biomass is in line with current environmental protection strategies. However, photo-reforming biomass suffers from poor catalyst stability and low conversion efficiency. Here, we designed fructose as a lignocellulosic model. The heterogeneous structure of Prussian blue coating was constructed with a special covalent bond structure of CoCNZn. This structure has a catalytic conversion mechanism that can accelerate electron transfer. Fructose was simultaneously converted to value-added platform compounds (5-HMF and formic acid) and gaseous fuels (CO, CH₄) with a conversion rate of up to 92.5%, which is more than 1.7 times than that of catalysts without adding Prussian blue. Hydrogen transfer and carbon transfer on the carbon atoms of fructose facilitates the production and accelerates the spillover of CO from formic acid. This work provides new ideas for the development of Prussian blue catalysts and the conversion of pentose.

The introduction of alkoxy side chains into the backbone of conjugated polymers is an effective way to change their properties. While the impact on the structure and optoelectronic properties of polymer thin films was well-studied in organic solar cells and transistors, limited research has been conducted on their effects on doping and thermoelectric properties. In this study, the effects of methoxy functionalization of conjugated backbones on the doping and thermoelectric properties are investigated through a comparative study of diketopyrrolopyrrole-based conjugated polymers with and without methoxy groups (P29DPP-BTOM and P29DPP-BT, respectively). Methoxy-functionalization significantly enhances doping efficiency, converting undopable pairs to dopable ones. This dramatic change is attributed to the structural changes in the polymer film caused by the methoxy groups, which increases the lamellar spacing and facilitates the incorporation of dopants within the polymer crystals. Moreover, methoxy-functionalization is advantageous in improving the Seebeck coefficient and power factor of the doped polymers, because it induces a bimodal orientational distribution in the polymer, which contributes to the increased splitting of Fermi and charge transport levels. This study demonstrates the impact of methoxy-functionalization of a conjugated polymer on doping behavior and thermoelectric properties, providing a guideline for designing high-performance conjugated polymers for thermoelectric applications.

The practical implementation of aqueous Zn-ion batteries (ZIBs) for large-scale energy storage is impeded by the challenges of water-induced parasitic reactions and uncontrolled dendrite growth. Herein, we propose a strategy to regulate both anions and cations of electrolyte solvation structures to address above challenges, by introducing an electrolyte additive of 3-hydroxy-4-(trimethylammonio)butyrate (HTMAB) into ZnSO₄ electrolyte. Consequently, the deposition of Zn is significantly improved leading to a highly reversible Zn anode with paralleled texture. The Zn/Zn cells with ZnSO₄/HTMAB exhibit outstanding cycling performance, showcasing a lifespan exceeding 7500 h and an exceptionally high accumulative capacity of 16.47 Ah cm⁻². Zn/NaV₃O₈·1.5H₂O full cell displays a specific capacity of ~130 mAh g⁻¹ at 5 A g⁻¹ maintaining a capacity retention of 93% after 2000 cycles. This work highlights the regulation on both cations and anions of electrolyte solvation structures in optimizing interfacial stability during Zn plating/stripping for high performance ZIBs.

Herein, we synthesized Cr³⁺/Ln³⁺ (Er³⁺, Tm³⁺)-codoped rare earth-based Cs₂NaScCl₆ double perovskite, and the near-infrared emission of Ln³⁺ can be excited by visible light through the energy transfer (ET) from Cr³⁺ to Ln³⁺. Moreover, there are two independent emission bands, which stems from ⁴T₂ → ⁴A₂ transition of Cr³⁺ (970 nm) and f-f transition of Ln³⁺ (1542 nm for Er³⁺ and 1220 nm for Tm³⁺), respectively. Particularly, both compounds have ultra-high photoluminescence quantum yield (PLQY) of 60% for 10%Cr³⁺/6%Er³⁺-codoped Cs₂NaScCl₆ (Er³⁺ emission: ∼26%) and 68% for 10%Cr³⁺/4.5%Tm³⁺-codoped Cs₂NaScCl₆ (Tm³⁺ emission: ∼56%), which can be attributed to the ultra-high ET efficiency from Cr³⁺ to Ln³⁺ and the similar ionic activity of Sc³⁺ and Ln³⁺ allowing more dopants enter the host lattice. Considering the excellent stability of the samples, we demonstrated Cr³⁺/Tm³⁺-codoped Cs₂NaScCl₆ in the applications of near-infrared imaging and night vision. Finally, we reported 10%Cr³⁺/4.5%Tm³⁺/9%Er³⁺-tridoped Cs₂NaScCl₆ and further applied it for optical thermometry.

The simple-structural and volatile solid additive 1,4-dibromobenzene (DBrB) can outperform organic solar cells (OSCs) fabricated with 1,4-diiodobenzene and 1,4-dichlorobenzene in terms of power conversion efficiency (PCE). A remarkable PCE of 17.0% has been achieved in a binary OSC based on DBrB-optimized photoactive materials processed from non-halogenated solvents, which is mainly attributed to the formation of a three-dimensional interpenetrating network and the orderly arrangement of the photoactive materials by improving the intermolecular interaction. This optimized morphology enables efficient charge transfer/transport as well as suppressed charge recombination, resulting in the simultaneous increase in all photovoltaic parameters. More importantly, we demonstrate that non-halogenated solvent-processed DBrB enabled PM6:Y6-HU OSCs with an impressive PCE of 18.6%, which is the highest efficiency yet reported for binary OSCs. This study suggests that the novel DBrB volatile solid additive is an effective approach to optimizing the morphology and thereby improves the photovoltaic performance of OSCs.

High-performance flexible and transparent chemical sensors are key to achieving wearable electronics. Graphene with high transmittance and electrical properties is a suitable material for flexible and transparent chemical sensors. However, graphene has low detectivity to chemical substances. Here, we report hybrid chemical sensors fabricated by introducing a highly flat and smooth metal–organic framework (MOF) on graphene. The graphene chemical sensors functionalized with MOF on SiO₂/Si wafer exhibit 22 times higher sensitivity of 6.07 μA ppm⁻¹ in detecting ethanol than that of pristine graphene transistors of 0.28 μA ppm⁻¹ and a low detection limit of 1 ppm. Furthermore, a flexible transparent 7 × 7 chemical sensor array exhibits great driving stability after the bending cycles of 10⁵ at a bending radius of 1.0 mm and shows sensitivity of 0.11 μA ppm⁻¹. Our findings demonstrate an efficient way to improve the chemical sensing ability of graphene for application in wearable chemical sensors.