ACS Applied Energy Materials最新文献

Hydrogen (H₂) production through the photocatalytic process of semiconductors is a promising way to turn solar energy into chemical energy. In recent times, host semiconductors are coupled with a variety of cocatalysts to improve photon absorption, facilitate fast charge carrier separation and transportation, and boost surface catalytic activity. Herein, we synthesized cocatalyst-free and pristine Sb₂S₃ nanorods using a simple hydrothermal method at an optimal temperature of 180 °C for different time durations from 3 to 6 h. The pristine Sb₂S₃ nanorods were comprehensively investigated for microstructural quality and quantity features using XRD, Raman, XPS, EDS, SEM, and TEM. Optical and photocatalyst charge carrier kinetics were studied using UV–Vis spectrophotometer, photoluminescence, and EIS studies. The surface area studies were conducted on Sb₂S₃ nanorods using Brunauer–Emmett–Teller (BET) analysis, and finally, photocatalytic hydrogen evolution tests were performed using gas chromatography (GC). The synthesis time has a significant impact on crystallinity, leading to improved structural and morphological properties with time. Specifically, Sb₂S₃ nanorods synthesized over 6 h exhibit an enhanced specific surface area of 7.52 m²/g and a pore size of 2.3 nm. The 6 h Sb₂S₃ nanorods exhibit a relatively longer lifetime (36 ms), indicating low recombination rate of photogenerated carriers, and promote efficient catalytic water splitting. The high specific surface area, low-intensity photoluminescence peak, less charge transfer resistance, and high transient photocurrent response of 6 h Sb₂S₃ nanorods, indicating that the enhanced synthesis time facilitates faster e^–-h⁺ separation and provides a larger surface area with a number of active sites. Under optimal conditions, the 6 h pristine Sb₂S₃ nanorods have demonstrated a high H₂ yield of 16.89 μmol·h^–1 for this material.

The fluorinated thienyl side chain and ring-fused electron-accepting (A) unit inevitably increase the synthesis complexity and product costs of state-of-the-art polymer donors (PDs), such as PM6 and D18, which may hinder the commercial application of organic solar cells (OSCs). Herein, we developed nonfused ring A units based on cyanoacrylate-substituted (oligo)thiophenes (OThs) through two or four steps, which were then copolymerized with a non-halogenated benzodithiophene (BDT)-based electron-donating (D) unit to produce a series of D–A-type PDs: PY-TQ, PY-2TQ, and PY-3TQ. The resulting polymers possess shorter synthetic routes and reduced costs compared with commonly used high-performance PDs. It was found that both cyanoacrylate substitution and the number of thiophene units have significant effects on the molecular structures and the optoelectronic and photovoltaic properties of these PDs. All polymers show excellent solubility, high molecular weight, and weak crystallinity due to their random chemical structure. Theoretical calculations reveal that PY-3TQ has a more coplanar backbone than the other two polymers because the inserted thiophene π-bridge can effectively reduce steric hindrance. Moreover, these PDs exhibit medium optical bandgaps (1.79–1.89 eV) and low-lying HOMO levels (approximately −5.40 eV), which are beneficial for their coordination with low-bandgap nonfullerene acceptors to construct efficient OSCs. The PY-2TQ:Y6-based OSC achieves a higher power conversion efficiency (PCE = 11.90%) compared to PY-TQ (5.83%) and PY-3TQ (8.20%), owing to more balanced carrier mobility, higher charge dissociation probability, weaker charge recombination, and superior active layer morphology. Additionally, it is proven that PY-2TQ has a certain generality to pair with other nonfullerene acceptors. More importantly, using PY-2TQ as the additional donor, the PM6:PY-2TQ:Y6 ternary OSCs achieve a decent PCE of up to 17.54%. This study highlights the potential of cyanoacrylate-substituted OThs as simple and efficient A units for designing high-performance and cost-effective PDs for OSC applications .

Entropically stabilized compositionally complex materials have recently emerged as a class of materials aimed at addressing the limited cycle stability of conventional conversion-based anodes in Li-ion batteries (LiB). Herein, we inaugurally represent first-row transition-metal-based high-entropy molybdates (HEMo) as a high-performance conversion-based LiB anode. The HEMo was synthesized by using a one-pot coprecipitation approach followed by annealing, resulting in a material with a layered morphology consisting of close-packed two-dimensional (2D) sheets. In a half-cell configuration, the HEMo demonstrated a high initial capacity of 1315 mAh/g at 0.1 A/g (second discharge) with an approximately 89% Coulombic efficiency. The HEMo exhibited excellent cycle stability, maintaining a specific capacity of 426 mAh/g over 1500 cycles at 0.5 A/g and a specific capacity of 206 mAh/g after 1800 cycles at 1 A/g. The charge storage mechanism was elucidated with an ex situ X-ray diffraction (XRD) study, showing a phase transition to the constituent metals during initial discharge and reoxidation to metal oxides during subsequent charging. A charge storage kinetics study showed a diffusion-dominated charge storage mechanism, the contribution of which further increased in the cycled cell, which is a possible reason behind the excellent long-term capacity retention of the HEMo. Additionally, the lithium-ion diffusion characteristics were examined across various states of discharge (SOD), revealing approximately a 10³-fold enhancement in lithium diffusivity from open circuit voltage (OCV) to an SOD of 0.5 V. Moreover, this trend exhibited high reversibility upon charging. Further, the practical utility of the HEMo as a LiB anode was validated in a full cell with a LiCoO₂ (LCO) cathode, exhibiting a stable capacity of 45 mAh/g after 200 cycles at 2C. Our initial findings should encourage further exploration and engineering of high-entropy molybdates as potential LiB anodes.

This article employs statistical analysis to explore the relationship between the performance of organic solar cells and synthetic accessibility (SA) of donor and acceptor materials. No significant correlation is identified between the power conversion efficiency (PCE) and SA scores. This study also utilizes the structure activity landscape index to examine how structural variations affect the PCE and SA score. Interestingly, structural alterations exhibit a more pronounced influence on PCE as compared to SA scores, particularly evident in donor molecules, which display greater structural diversity. Chemical similarity analysis was conducted through heatmap and cluster analysis.

Lithium–sulfur (Li–S) batteries are present as a promising energy storage system. Inhibiting the polysulfide shuttle effect is one of the most important research goals for the practical application of Li–S batteries. The introduction of organic functional groups to the sulfur cathode via inverse vulcanization has been an effective strategy to improve its properties and, in turn, the performance in Li–S batteries. In this report, an inverse vulcanized polymer (IVP) containing a tailor-designed quaternary ammonium salt named poly(S-r-TAEAB) was synthesized and integrated into the cathode of Li–S batteries. Systematic studies were conducted with the poly(S-r-TAEAB) cathode as well as the traditional sulfur and the IVP cathode, which only possess tertiary amine functional groups. Poly(S-r-TAEAB) reduces lithium polysulfide dissolution through the covalent bonding of sulfur atoms to the carbon framework. Importantly, the poly(S-r-TAEAB) cathode was demonstrated to adsorb lithium polysulfides, further suppressing the shuttle effect. The presence of the quaternary ammonium salt in the poly(S-r-TAEAB) was found to be critical for the acceleration of sulfur redox kinetics, fast Li-ion diffusion, favorable electrode/electrolyte interface, and improved mechanical properties. Due to these features, the poly(S-r-TAEAB) cathode exhibited significantly higher capacity retention over 100 cycles and enhanced rate performance compared with the traditional sulfur cathode.

Rudorffite material, silver bismuth iodide, is one of the promising lead-free alternatives for photovoltaic applications due to its high absorption coefficient, low toxicity, and relatively better stability. Here, we report on the effects of alkali halide additive in the absorber material AgBiI₄, focusing on its material properties and solar cell devices. The inclusion of NaI significantly improved the film quality with compact and pinhole-free morphology and better crystallinity. The device with rudorffite material with NaI additive demonstrated a notable increase in the PCE from 1.33 to 3.72%, along with improved device stability. The device analysis confirmed that NaI incorporation in AgBiI₄ modulates the optoelectronic quality, effectively suppressing charge recombination and enhancing charge extraction within the device. Thus, this work corroborates that additive engineering is an effective strategy for improving both the efficiency and stability of AgBiI₄-based rudorffite solar cells, underscoring their potential in sustainable photovoltaic applications.

Given the inherent limitation of intercalation chemistry-based Li-ion batteries, much research attention has been focused on the next-generation batteries with a Li metal anode. Lithium–sulfur (Li–S) batteries have become the spotlight of battery research due to the ultrahigh energy density of the sulfur cathode (2600 Wh kg^–1). However, the notorious shuttle effect of polysulfides leads to a rapid loss of active materials, which results in the rapid decay of Li–S batteries. Consequently, various strategies have been proposed to improve the cycle stability, and prolonged cycle life has been achieved even under a low electrolyte-to-sulfur ratio. Nevertheless, the self-discharge of Li–S batteries, which influences the shelf life of Li–S batteries, has not received adequate attention. To push Li–S batteries for practical application, there is an urgent need to solve the issues of self-discharge. In this review, we initially introduce the working mechanism of Li–S batteries and discuss the origin of self-discharge of Li–S batteries. Subsequently, we summarize the recent advances in suppressing the self-discharge of Li–S batteries from the perspectives of structured sulfur host design, electrolyte optimization, functionalized separators, and solid-state electrolyte construction. Eventually, we propose a future research direction for prolonging the shelf life of Li–S batteries.

Lithium–sulfur (Li–S) batteries continue to encounter challenges related to the shuttle effect and interfacial issues associated with lithium metal anodes in practical applications. In this study, the multifunctional electrolyte organic nitrogen–fluorine additive 2,5-difluoropyrazine (2,5-DFP) was proposed for Li–S batteries, highlighting its merits from several perspectives. The additive not only facilitates the formation of energy-reducing intermediates during the reaction of sulfur cathode with lithium polysulfides (LiPSs) but also effectively modulates the molecular orbital energy levels of LiPSs and enhances their redox kinetics. The additive can also suppress dendrite growth by forming a dense and smooth organic–inorganic hybrid solid electrolyte interphase (SEI) on the lithium anode such as lithium fluoride. Consequently, the developed cell shows a high capacity of 1215.6 mAh g^–1 and maintains a capacity of 588.1 mAh g^–1 even at a high rate of 4 C. This study demonstrates that 2,5-DFP can serve as a functional electrolyte additive, offering insights for the design of electrolytes for Li–S batteries.