ACS Applied Energy Materials最新文献

The ethylene-vinyl acetate (EVA) copolymer, a popular transparent adhesive interlayer material for solar cell encapsulation, can be formed by a simple extrusion process at a relatively low temperature without the aid of an organic solvent. However, the inherently poor ionic conductivity (σ) restricts its application as a solid polymer electrolyte (SPE) for laminated WO₃-NiO electrochromic devices (ECDs). Here, we propose a strategy to improve the σ by a water modification in the EVA matrix. The results demonstrate that the sample treated at 50 °C and 25% relative humidity (RH) for 1 h exhibits a higher σ of 3.80 × 10^–4 S cm^–1, as well as a visual transmittance of more than 90%, a tensile strength of 1.61 MPa, and an excellent thermal stability up to 219 °C. Using this kind of EVA-based SPE (EVA-SPE) as the interlayer, WO₃-NiO based ECDs with sizes varying from 2.5 × 5 to 20 × 20 cm² have been successfully laminated and exhibit favorable EC performances. Besides, the water modification is conducive to an enlarged light modulation range (ΔT) for the laminated ECD in the near-infrared zone, ensuring a high energy efficiency when the device is used as a smart window in buildings.

A series of (BDD-X)_n conjugated polymers, comprised of 5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c′]dithiophene-4,8-dione (BDD) and X = B (P1), X = TBT (P2), and X = TBTBT (P3), where T = thiophene and B = benzo[c][1,2,5]thiadiazole, have been synthesized and applied as dopant-free hole-transport layer materials in perovskite solar cells (PSCs). We explored the effect of the molecular structure of the block X on the optical and electronic properties of the polymers, the nanoscale morphology of their films, and the impact of all these parameters on the performance of the polymers in PSCs. As a result, using the polymer P1 with the simplest molecular architecture provided a power conversion efficiency (PCE) of 20.1% in solar cells, thus outperforming devices assembled with the more sophisticated polymers P2–P3 or the reference poly(triarylamine)-based hole-transport materials. The enhanced device performance is attributed to a better HOMO alignment of P1 with respect to the perovskite valence band, a low concentration of defects and suppressed carrier recombination at the P1/perovskite interface and, most importantly, a highly uniform film structure, as revealed by atomic force microscopy and infrared scattering near-field optical microscopy (IR s-SNOM) techniques. The supramolecular interactions of the building blocks of polymers P1–P3 with the perovskite films, resulting in the passivation of surface defects, were further studied by density functional theory calculations.

The hydrophilic property of the catalytic interface has been seldom focused on particularly, although many green and sustainable catalysis transformations involve water. Addressing the issue, we prepared Dy–Ni–P catalysts for the 5-hydroxymethylfurfural oxidation reaction (HMFOR) to 2,5-furandicarboxylic acid (2,5-FDCA) in this work. The catalysts were clarified as (DyPO₄)_m/Ni₂P composites with molar ratio m within 0.08–0.28 by ICP-OES, XRD, XPS, and HRTEM characterizations. The catalytic performance of samples was comprehensively analyzed by the HPLC technique, ¹H NMR spectra, and various electrochemical tests, indicating that the introduction of DyPO₄ in a proper amount (m = 0.16) would significantly enhance the catalytic efficiency versus singular Ni₂P in terms of 2,5-FDCA yield (91 vs 26%), selectivity (99 vs 47%), and Faradaic Efficiency (F.E.: 98 vs 70%). The enhancements were accompanied by improved kinetic features such as the Tafel slope (53 vs 95 mV dec^–1) and intrinsic activity (3.3 vs 1.7 mA cm^–2). The boosting endowment (DyPO₄)_m/Ni₂P stands among the top members of reported Ni-based HMFOR catalysts. The promoter effect of DyPO₄ was further investigated by H₂O-TPD, contact angle, zeta potential, OCP, and EIS measurements. It was testified that the nonhydrophilic Ni₂P surface would be converted to a hydrophilic composite interface with the introduction of DyPO₄; in line with the essential change, transfer of reactants and activation of water were obviously intensified with the lowered charge transfer resistance along the catalytic interface, which was responsible for the enhanced catalytic behavior of (DyPO₄)_m/Ni₂P versus Ni₂P. The above discovery made the topic regarding water indicate that the hydrophilic property of the catalytic interface played a significant role in facilitating heterogeneous catalysis transformations involving water; exampled by the current (DyPO₄)_m/Ni₂P for HMFOR, rare-earth phosphate could be referred to as an outstanding hydrophilic promoter to innovate excellent catalysts for technology-important chemical engineering involving water.

Membranes are an integral component of electrochemical flow reactors (EFRs), allowing charge carrier transport between electrodes while blocking active species. Many EFR technologies utilize cation-exchange membranes (CEMs) extensively due to their high conductivity and chemical stability; however, CEMs do not obstruct cationic active species and cause unwanted electrolyte cross-contamination in EFR technologies that use cations as active species, e.g., redox flow batteries (RFBs) and electrodialysis. Anion-exchange membranes (AEMs) innately block cations; however, they are not sufficiently durable. Developing strategies to enhance their durability is necessary to expand their application in RFBs and similar EFRs. This work investigates the morphology control of immiscible polymer-blended AEMs via tuning the blend composition and casting temperature. Marangoni-Bénard effect was identified as the dominant mechanism behind the perturbations in the casting solution film. Marangoni cells appear at AEMs cast at >40 °C, leading to desirable lateral phase separation of polymers. The ionic conductivity of lateral phase-separated AEMs improved with lowering the casting temperature, indicating that excessively heightened perturbations in the casting films damage the conductivity routes. Adding 20% PVDF-co-HFP to the AEM reduced the water uptake (30 vs 58%), hence increasing the durability of the AEM (conductivity loss of 21 vs 63% over a week) while sacrificing minimal ionic conductivity (11 vs 13 mS·cm^–1). Hence, polymer blending is a useful strategy to improve the durability of membranes for RFBs and similar electrochemical systems.

The advancement of a competitive Mg-ion battery is restricted by the limited mobility of Mg ions in the current host materials. Herein, LiCl is added as a supporting salt to an MgCl₂ salt-based, polyethylene glycol (PEG) solvent-in-water electrolyte (SIW) to obtain the H-PG-Mg electrolyte. The LiCl addition is employed to benefit from its reported synergistic effects in minimizing cell potential and shielding effects, suppressing dendritic formation, and promoting the ability of MgCl₂ deposits to dissolve and expose a fresh anode surface. The H-PG-Mg@Li electrolyte shows the highest electrochemical stability window (ESW) of 3.3 V, which is 1.5 times higher than the LiCl-free electrolyte, and the highest ion transference number of 0.70. MgO-V₂O₅–P₂S₅ (G) electrode is tested in a three-electrode configuration and displays superior capacity retention of 60% after 1000 cycles. The G/H-PG-Mg@Li/Mg cell exhibits the best cycling stability of up to 150 cycles. The ability of the G cathode to reversibly accommodate Mg²⁺ cations in H-PG-Mg@Li due to lower overall charge density was highlighted using ex-situ elemental analysis, where the ratio of the ions followed the charging and discharging processes. These results highlight LiCl addition and SIW strategies as effective approaches to upgrading the electrochemical performance of current aqueous Mg batteries.

In search of anode materials for organic batteries, we propose benzoxazole-based redox-active polymers. We report theoretically calculated redox properties of the monomer and polymer based on small polymer chain models using density functional theory (DFT). Subsequently, a straightforward synthesis of poly(4-(benzoxazol-2-yl)-1-(4-vinyl benzyl)pyridinium chloride) (PBO) via radical polymerization is presented. To our knowledge, PBO is the first representative of this class of redox-active polymers applied in batteries, and it has a theoretical specific capacity of 76.8 mA h g^–1 (first redox process). PBO was utilized as an anode and capacity-limiting electrode in an all-organic radical battery using aqueous- and organic-based electrolytes as well as 2,2,6,6-tetramethylpiperidinyl-N-oxy (TEMPO) derivatives as cathodes, providing a cell voltage of 1.3 and 1.4 V in aqueous- and organic-based electrolytes, respectively. The material revealed 99% capacity utilization at 1 C in the first cycle using an organic electrolyte (1 M LiClO₄ in CH₃CN) and more than 75% capacity utilization in an aqueous electrolyte (1 M LiClO₄ in H₂O). In both systems, after rate capability tests (from 0.2 to 50 C), the cells were cycled again at 1 C, where 50% of the initial capacity was retained after 100 cycles. Even though, due to the linearity and the molar mass of PBO, a capacity decay is observed during cycling tests, this study opens a promising class of molecules for the development of anode materials.

Developing transition metal selenide materials with high capacity, excellent rate capability, and satisfactory durability presents significant challenges due to their sluggish electrochemical kinetics, limited electrical conductivity, and detrimental volume change. To address these challenges, we have prepared four Ni₃Se₂-based cathode materials, named as Ni₃Se₂, Mo-Ni₃Se₂, V-Ni₃Se₂, and MoV-Ni₃Se₂, with selenium vacancies through a one-step hydrazine-hydrothermal process. Co doping with Mo and V demonstrates the synergistic effects of the bimetallic dopants and induces the generation of a higher density of selenium vacancies. The incorporation of Mo/V codoping and rich selenium vacancies confers upon MoV-Ni₃Se₂ obvious advantages, such as improved electrical conductivity, enhanced structural flexibility, sufficient redox reaction sites, and reduction of charge-transfer resistance. Consequently, the MoV-Ni₃Se₂ electrodes achieve a peak specific capacity of 1.78 mAh cm^–2 at a current density of 2 mA cm^–2 and sustain a high rate capability of 0.96 mAh cm^–2 at 50 mA cm^–2. The MoV-Ni₃Se₂//Zn battery delivers an impressive surface energy density of 2.93 mWh cm^–2 and a remarkable power density of 51.55 mW cm^–2 with outstanding cycling stability (capacity retention of 87.44% at 20 mA cm^–2 after 3000 cycles). This study provides valuable insights for the development of high-performance cathode electrodes by synergetic engineering of doping and defects for aqueous nickel–zinc batteries.

Hyper-cross-linked polymers (HCPs) are one of the important classes of porous organic polymers and are known for their easy preparation under mild conditions by employing readily available precursors. Though there are many HCPs synthesized out of electron-rich π-systems, literature reports of HCPs with π-systems having electron-deficient functional groups such as imides are sparse. This is challenging due to the inherent inefficient nature of Friedel–Crafts alkylation on π-systems with electron-deficient functional groups. In this study, we report a rational strategy for the synthesis of HCPs using benzoperylene imide (BPI) based dipolar π-systems via Friedel–Crafts alkylation. This is achieved by attaching a phenylbutane chain at the imide position, in which the phenyl ring of the phenylbutane serves as the site for Friedel–Crafts alkylation. The resultant BPI-HCP-I exhibits a Brunauer–Emmett–Teller surface area of 544 m²/g and strong visible-light absorption up to 600 nm. On the other hand, HCPs synthesized without any phenyl ring at the imide side chain (BPI-HCP-II and BPI-HCP-III) exhibit poor surface area due to inefficient cross-linking via Friedel–Crafts alkylation. Interestingly, BPI-HCP-I showed good electrochemical performance, exhibiting a specific capacitance of 112 F/g, highlighting its reversible proton storage capability. Our study provides the pathway for the synthesis of HCPs with large dipolar π-systems, which are good candidates for strong visible-light absorption and energy storage applications.

Increasing the cutoff voltage for charging lithium batteries can increase the capacity density of lithium-ion batteries. Still, it is also accompanied by some adverse effects, including electrode material corrosion and electrolyte loss. To mitigate these adverse effects, this article reports on a high-voltage catholyte additive, 2,4,6-tris(4-fluorophenyl)cyclo-boroxine (PFTB). Calculation demonstrates that the HOMO energy level of PFTB is lower than that of typical solvents. Consequently, PFTB can decompose selectively to generate a robust and conductive protective CEI membrane. This reduces the occurrence of interfacial side reactions and thus protects the electrode material’s structural integrity. The outcomes of extended cyclical assessments demonstrate that the capacity retention rates are 83.7% (4.2 V), 89.0% (4.3 V), 80.4% (4.4 V), and 81.8% (4.5 V), respectively, when 1.0 wt % PFTB is incorporated into the standard electrolyte. The results of the physical characterization demonstrate that PFTB undergoes preferential decomposition on the cathode, forming a CEI membrane rich in F and B elements. These elements can effectively enhance the conductivity and stability of the CEI membrane. Therefore, adding PFTB to the electrolyte as an additive provides an economical and effective method for studying high-energy lithium batteries.

Graphitic carbon nitride (GCN), a graphite-like material composed of aromatic tri-s-triazine units, has recently gained recognition as a promising candidate for supercapacitor electrode applications. Its abundant availability, metal-free composition, high nitrogen content, and responsiveness to environmental conditions make GCN a highly attractive material for energy storage solutions. Despite this potential, challenges remain in optimizing its specific capacity and energy density. This review stands out by comprehensively analyzing various GCN synthesis methods such as hydrothermal, solvothermal, and sol–gel techniques and critically examining how these methods influence electrochemical performance. A particular focus is placed on identifying optimal synthesis techniques through a detailed comparison of their impact on key functional parameters. This review differentiates from previous studies’ in-depth exploration of advanced strategies to enhance GCN’s electrochemical properties. Specifically, the review delves into innovative approaches like element doping and hybridization with polymers, metals, and carbon-based materials, offering new pathways to significantly boost the performance of GCN electrodes. These cutting-edge strategies have not been systematically explored in other reviews, positioning this article as a forward-thinking contribution to the field. In addition, the review takes a broader, interdisciplinary approach by examining GCN’s functionality in other applications, such as water splitting, and identifying critical commonalities between the functional parameters of these applications and those of supercapacitors. This cross-application analysis, rarely addressed in previous literature, opens new avenues for GCN development, suggesting that insights from related fields can accelerate the optimization of GCN as a supercapacitor electrode. By emphasizing the innovative combination of element doping and metal-based hybridization, this review offers a novel perspective on advancing GCN technology. It also addresses current challenges and provides practical recommendations, making it a pivotal resource for future breakthroughs in energy storage and related applications.