EcoMat最新文献

Pt-based electrocatalysts for glycerol oxidation reaction (GOR) exhibit low durability due to the inactivation of Pt through rapid poisoning under oxidative conditions. Thus, bimetallic PtBi was strategically synthesized using BiOI as a photoactive intermediate for the uniform photoelectrodeposition of Pt. The nanostructured Pt–Bi was electrochemically reduced from a Pt/BiOI medium, and the GOR-activated Pt–Bi electrocatalysts (G–Pt–Bi) were obtained via a subsequent electrochemical activation process. Here, abundant Bi sites in PtBi can prevent Pt poisoning and effectively provide adsorbed OH⁻ for the GOR on Pt sites. Consequently, it allows the operation in low onset potential for GOR with a high mass activity of 13.35 A mg_Pt ⁻¹ at 0.85 V_RHE in alkaline solution. The GOR products obtained using G–Pt–Bi were identified as glycolate and formate by ¹H-nuclear magnetic resonance without the interruption of the hydrogen evolution reaction, and it finally enables the operation of a membrane-free two-electrode system. In situ electrochemical impedance spectroscopy demonstrates that the G–Pt–Bi exhibit superior GOR kinetics and higher resistance to Pt inactivation compared with conventional Pt/C. This study suggests a novel design for a G–Pt–Bi architecture in developing durable and high-mass-activity Pt catalysts for the GOR.

Two-dimensional Ruddlesden-Popper (2D RP) layered metal-halide perovskites have garnered increasing attention due to their favorable optoelectronic properties and enhanced stability in comparison to their three-dimensional counterparts. Nevertheless, precise control over the crystal orientation of 2D RP perovskite films remains challenging, primarily due to the intricacies associated with the solvent evaporation process. In this study, we introduce a novel approach known as reverse-cool annealing (RCA) for the fabrication of 2D RP perovskite films. This method involves a sequential annealing process at high and low temperatures for wet perovskite films. The resulting RCA-based perovskite films show the smallest root-mean-square value of 23.1 nm, indicating a minimal surface roughness and a notably compact and smooth surface morphology. The low defect density in these 2D RP perovskite films with exceptional crystallinity suppresses non-radiative recombination, leading to a minimal non-radiative open-circuit voltage loss of 149 mV. Moreover, the average charge lifetime in these films is extended to 56.3 ns, thanks to their preferential growth along the out-of-plane direction. Consequently, the leading 2D RP perovskite solar cell achieves an impressive power conversion efficiency of 17.8% and an open-circuit voltage of 1.21 V. Additionally, the stability of the 2D RP perovskite solar cell, even without encapsulation, exhibits substantial improvement, retaining 97.4% of its initial efficiency after 1000 hours under a nitrogen environment. The RCA strategy presents a promising avenue for advancing the commercial prospects of 2D RP perovskite solar cells.

Composite polymer electrolytes (CPEs), produced by incorporating inorganic nanoparticles (NPs) into polymer matrices, have gained significant attention as promising candidates for solid-state lithium metal batteries (LMBs). However, the aggregation of dense inorganic fillers results in nonuniform CPEs, thereby impeding LMB performance. Here, we fabricated in-situ photo-polymerized CPEs by incorporating different weight ratios (0–20 wt%) of Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) into a polymer electrolyte system composed of poly(butyl acrylate)-based elastomer and succinonitrile-based plastic crystal phases. The rapid photo-polymerization process (~5 min) enabled homogeneous dispersion of LLZTO within the CPE matrix at 10 wt% LLZTO (L10), resulting in the high ionic conductivity (1.02 mS cm⁻¹ at 25°C) and mechanical elasticity (elongation at break ≈ 1250%) compared to those of CPE without LLZTO (L0). As a result, the L10-based LMB with a LiNi_0.8Co_0.1Mn_0.1O₂ cathode exhibited a high capacity of 166.7 mAh g⁻¹ after 200 cycles at 0.5C, significantly higher than those of L0 (74.0 mAh g⁻¹) and L20 (104.8 mAh g⁻¹). In comparison, in-situ thermal polymerized CPE with 10 wt% LLZTO NPs showed aggregation of NPs due to slow polymerization kinetics (~2 h), resulting in inferior LMB cycling performance compared to the L10. This work highlights the importance of in-situ photo-polymerized CPEs with homogenous dispersion of inorganic NPs to achieve high ionic conductivity and mechanical robustness suitable for the stable operation of LMBs.

All-solid-state battery (ASSB) systems have attracted significant attention due to their high energy density and safety compared with conventional batteries. Moreover, the application of Mn-based cation-disordered rock-salt (DRX) that possesses cost-effectiveness and high energy density on the ASSB system as a cathode is expected to be the superior next-generation battery system. However, DRX cathodes require high carbon contents due to their low electronic conductivity, leading to challenges in introducing them in ASSB systems, as the high carbon levels can cause electrolyte decomposition which potentially affects overall electrochemical performance. In this work, we applied Mn-based DRX cathodes to ASSB systems within a voltage range of 1.5–4.8 V and evaluated the suitability of cathode composites using halide and sulfide electrolytes as catholytes, respectively. The experimental results showed that the high carbon contents induced side reactions with the argyrodite, resulting in electrochemical degradation such as the drop of initial discharge voltage and the capacity fading. Meanwhile, cathode composites using a halide electrolyte exhibited relatively enhanced electrochemical performance due to its high oxidation stability regardless of the high amount of carbon contents. Consequently, the electrochemical reactions of the electrolyte, influenced by the content of conductive additives and the type of electrolyte, had a great impact on the performance of ASSB systems. This study provides a deep understanding of the interplaying among solid electrolytes, cathodes, and conductive additives and offers an important foundation for future research and development in ASSB systems.

Tin-halide perovskite solar cells (THPSCs), while offering low toxicity and high theoretical power conversion efficiency, suffer from inferior device performance compared to lead-based counterparts. The primary limitations arise from challenges in fabricating high-quality perovskite films and mitigating the oxidation of Sn²⁺ ions, which leads to severe non-radiative voltage losses. To address these issues, we incorporate the rare-earth element erbium chloride (ErCl₃) into PEA_0.15FA_0.70EA_0.15SnI_2.70Br_0.30 perovskite to effectively control the nucleation and crystal growth, significantly influencing the morphology of the perovskite films. As a result, the ErCl₃-processed THPSC exhibits an impressive open-circuit voltage (V_OC) of 0.83 V and power conversion efficiency (PCE) of 14.0% with the superior light and air stability, compared to the control device (V_OC = 0.77 V and PCE = 12.8%). This ErCl₃-strategy provides a feasible solution for high-performance THPSCs by regulating nucleation/crystallization kinetics and mitigating excessive crystal defects during the preparation process of lead-free perovskites.

In perovskite solar cells (PSCs), expensive gold or silver metal has traditionally been utilized as the rear electrode for highly efficient performance. In this context, carbon nanotube (CNT) electrodes have been considered promising rear electrodes because of their excellent electrical conductivity, mechanical strength, and chemical stability in PSCs. Despite these favorable characteristics, concerns have been raised about the power conversion efficiency (PCE) and stability of PSCs based on CNTs due to the porosity of CNT electrodes. In this study, we employed both poly(triarylamine) (PTAA) infiltration and rear electrode hidden encapsulation approaches to address issues related to the porosity of thin-walled carbon nanotube (TWCNT) electrodes to achieve high efficiency and stability. The infiltration of low-molecular-weight PTAA into the TWCNT electrode reduced electrode porosity while simultaneously improving the interfacial contact of the TWCNT layer with the perovskite layer. Furthermore, a novel encapsulation design was employed to prevent air and water exposure of the TWCNT electrode, which significantly enhanced device stability. PSCs with TWCNT rear electrodes developed on the basis of these strategies have the best PCE of 19.5% and show long-term stability, retaining 96% and 74% of the initial PCE after 225 h at maximum power point tracking under AM 1.5G illumination and 916 h at 85°C/85% relative humidity, respectively.

Research on the production and utilization of hydrogen energy is essential to overcome the environmental issues caused by fossil fuels. Herein, we anchor PtNi nanoalloy clusters (Pt-Ni NACs) on nitrogen-doped graphene oxide (NrGO) by a facile microwave-assisted synthesis and analyze the variations of catalyst properties based on the PtNi composition and the presence of nitrogen. Ni inclusion in the Pt matrix can induce lattice strain and change the electronic structure, while the doped nitrogen into the graphene can enhance electron transfer and improve the durability of the catalyst through strong chemical bonding with the alloy clusters. TEM analysis discovers that the NACs are uniformly decorated in a few-nanometer-size on the graphene surface, and the formation of the PtNi NACs and structural changes according to composition are confirmed through XRD and XPS. In addition, the structural changes due to N-doping and its bonding with the NACs are observed through Raman spectroscopy and XPS. Electrochemical measurements reveal that Pt_2.6Ni NACs/NrGO exhibits the highest ORR onset potential (0.893 V) and the lowest HER overpotential at 10 mA cm⁻² (22 mV) among other catalysts, and those activities are almost unchanged under long-term durability tests. From these results, Pt_2.6Ni NACs/NrGO is utilized in a zinc-air battery (ZAB) system, demonstrating better battery performance than commercial Pt and Ir-based catalysts. Moreover, it is applied to hydrogen collection, showing linear trend in hydrogen production over time, confirming the catalyst's availability in hydrogen production and utilization.

Goals of high efficiency, morphological analysis, and the ability to produce organic solar cell (OSC) sub-modules using halogen-free solvents are demanding. In this study, a robust conjugated polymer with thienothiophene π-spacer with pendant alkyl side chain (NapBDT-C12) was synthesized and used to fabricate sub-modules. Excellent efficiencies were demonstrated by a NapBDT-C12 integrated ternary blend, which was used to produce stable small-area-to-sub-module devices using O-xylene. The efficiency of the NapBDT-C12 added small-area ternary devices (PM6:NapBDT-C12:L8-BO) was 18.71%. Owing to the controlled homogeneity of the blend with favorable nanoscale film morphology, enhanced carrier mobilities, and exciton dissociation/splitting properties, contributed to the efficiencies of small-area-to-sub-module OSCs. Moreover, a 55 cm² sub-module with an efficiency of 14.69% was accomplished by bar coating using O-xylene under ambient conditions. This study displays the potential of a ternary blend based OSC device to produce high efficiency scalable sub-modules at ambient conditions.

Lithium metal batteries offer a promising solution for high density energy storage due to their high theoretical capacity and negative electrochemical potential. However, implementing of these batteries faces challenges related to electrolyte instability and the formation of a solid electrolyte interphase (SEI) on the lithium (Li) metal anode. The decomposition of liquid electrolytes leading to the creation of the SEI emphasizes the significance of the type of Li salt, solvent, and additives designed and used, as well as their interactions during the formation of the SEI. For practical applications, ensuring both the reversibility of the Li metal anode and electrolyte stability at high voltages is crucial. In this review, we explore recent advancements in addressing these challenges through new designs of electrolytes and SEI engineering practices. Specifically, we investigate the effects of electrolyte systems, including carbonate-based and ether-based solutions, along with modifications to these electrolyte systems aimed at achieving a more stable interface with the Li metal anode. Additionally, we discuss various artificial SEI structures based on organic and inorganic components. By critically examining recent research in these areas, this review provides valuable insights into current state-of-the-art strategies for enhancing the performance and safety of Li metal batteries.

Stability and oxidation are major bottlenecks in improving the performance of Sn-based perovskite solar cells. In this study, we present the formation of an n-type Cs₂SnI₆ double-perovskite (Sn-DP) layer on a (PEAI)_0.15(FAI)_0.85SnI₂ perovskite (Sn-P) layer using an orthogonal solution-processable spray-coating method. This novel approach achieves a minimized V_oc loss of 0.38 V and a PCE of 12.9% under 1 sun conditions. The n-type DP layer effectively passivates tin vacancies, suppresses Sn²⁺ oxidation, reduces defects, and enhances electron extraction. Furthermore, the Sn-DP/Sn-P-based solar cells exhibit excellent light-soaking stability for 1000 h in the air under continuous one sun illumination, which is attributed to the stable Sn⁴⁺ state of the DP layer. Our experimental and theoretical investigations reveal that the type-II band alignment between Sn-DP and Sn-P enhances the stability of the solar cells. The proposed Sn-DP/Sn-P architecture offers a promising pathway for developing Sn-based solar cells.