ACS Applied Energy Materials最新文献

Lithium metal has become an ideal anode for high-energy-density lithium-ion batteries due to its unique theoretical capacity and potential advantages. However, the volume effect, uneven deposition, and dendrite growth of lithium metal can seriously shorten the service life of the battery. A 3D structural design and a lithium-friendly interface are considered effective ways to improve lithium metal negative electrodes. Hence, this article successfully prepared a sponge carbon (SC) scaffold rich in N-sites using melamine as the raw material. Pyridine N and pyrrole N, which can enhance surface activity, are distributed in the SC structure and can serve as lithium nucleation sites to promote the uniform deposition of lithium metal. Compared with hard carbon (HC), SC exhibits significant improvements in polarization potential and cycle life. The deposition overpotential of the SC battery is only 36 mV, and its cycle life is as long as 1800 h, while it maintains a high Coulombic efficiency of over 98%. Even at a high deposition capacity of 10 mAh cm^–2, SC can still stably deposit for over 1000 h. In addition, the 3D flexible carbon skeleton of SC provides a large space for buffering the volume expansion of lithium metal, which effectively suppresses the growth of lithium dendrites. The full-cell performance results demonstrate that the SC still retains a capacity retention rate of 98.4% after 200 cycles at 1 C, whereas the capacity retention rate of HC drops to 73.5%. Moreover, the long cycle performance and rate capability of SC full cells are both superior to those of HC full cells. This article improves the reversibility of lithium metal deposition/stripping by constructing a 3D self-doped N-sponge carbon skeleton and provides a reference for the development of long-life lithium metal batteries.

Upgrading from a single S-scheme to a double S-scheme heterojunction by inserting another semiconductor affords a challenging means of concurrently augmenting the charge-transfer dynamics and surface reaction kinetics while preserving extraordinary redox ability. Herein, a 2D Cu_xSe_y nanosheet is inserted between a 1D CoTiO₃ nanorod and 2D petals of a NiCo-LDH nanoflower to construct a double S-scheme CoTiO₃/Cu_xSe_y/NiCo-LDH 1D/2D/2D ternary heterojunction through a combination of calcination and hydrothermal processes. In comparison to NiCo-LDH and CoTiO₃/NiCo-LDH, the ternary hybrid exhibited 7.2 and 2.5 times higher H₂ evolution rates, respectively, and it also displayed a better H₂O₂ production of 978 μmol h^–1 g^–1, which was 2.8, 2.1, and 1.6 times higher than those of CoTiO₃, NiCo-LDH, and the CoTiO₃/NiCo-LDH nanohybrid, respectively. Further, it parades the conversion efficiencies of 9.1 and 0.013% for H₂ and H₂O₂ production, respectively. The enhanced activities are due to the formation of a double S-scheme heterojunction, where Cu_xSe_y acts as a charge-transfer mode switcher. The Ni/Ti–Se bond at the dual interface of the ternary heterojunction served as a bridge for the effective separation of charge carriers. The double S-scheme charge transfer was validated by the scavenger experiment, work function, in situ XPS, and in situ KPFM analysis. This study provides a valuable understanding of the double S-scheme charge transfer with an increasing overall efficiency of the photoredox behavior.

Materials and cell components used in CO₂ electrolysis have largely been adapted from technologies initially developed for water electrolysis and fuel cells. However, electrochemical CO₂ reduction introduces distinct material challenges due to the unique chemical environment in this process. In this study, we conducted ex-situ 1000 h stability tests on commonly used anion exchange membranes, exposing them exclusively to electrolytes and organic molecules used or produced during CO₂ electrolysis, at concentrations relevant to and compatible with postseparation processes. Notably, 15% w/w n-propanol and 5 M acetic acid caused complete dissolution or partial disintegration of the membranes unless cross-linking was present and remained stable throughout the test. When the membranes stayed physically intact, most of them exhibited excellent chemical stability in alkaline medium containing alcohols or formic acid, which was confirmed by vibrational spectroscopy and ion exchange capacity measurements. However, exposure to alcohol-and acid-containing solutions led to a substantial increase in swelling and water uptake, with potential implications for mechanical stability, ion/product crossover, and compression management of adjacent components. The potential effects of CO₂ electroreduction products on membrane stability, their subsequent impact on electrolyzer performance, and mitigation strategies are discussed.

Generally, formamidinium (FA)-based halide perovskite thin films are fabricated using halide precursors, such as PbI₂ and FAI, but this approach often leads to stoichiometric distortions, resulting in perovskite films with structural defects and reduced crystallinities. These problems can adversely influence power conversion efficiencies and open-circuit potentials of perovskite solar cells. In this study, we propose a microcrystalline perovskite powder (MCP) synthesized by controlling the stoichiometry of the FAI precursor. We optimize the synthesis of α-FAPbI₃ powder using 1.1 equiv of FAI. Interestingly, the synthesized black powder produced an excellent crystallinity and phase stability for up to six months. Remarkably, the MCP forms large colloids in solutions that are stably cohesive, promoting spontaneous nucleation and enabling the fabrication of low-defect thin films. Consequently, perovskite solar cells fabricated using the MCP display significantly improved efficiencies of 23.12% compared to those (19.64%) of the cells fabricated using the conventional PbI₂ and FAI precursors. This approach highlights the potential of MCPs for use in enhancing the performances and stabilities of perovskite-based devices.

The development of stable Ni-rich cathodes is critical to the advancement of high-energy lithium-ion batteries. Their practical deployment, however, remains severely limited by rapid interfacial degradation and capacity fading that stem from their inherent surface reconstruction, oxygen evolution, strenuous phase transitions, and micro- and crystal structure degradation, especially when cycled above 4.1 V. Herein, we report an electrolyte design strategy employing tris(trimethylsilyl) borate (TMSB) and vinylene carbonate (VC) as additives to enhance the electrochemical performance of Li[Ni_0.9Co_0.05Mn_0.05]O₂ (NCM90) cathodes. Electrochemical evaluation reveals that the TMSB-VC combination achieves an exceptional capacity retention of 97.3% after 100 cycles at 0.5 C (90 mA g^–1). The inclusion of TMSB in the electrolyte formulation promotes hydrofluoric acid scavenging, suppresses parasitic reactions, and promotes the formation of an inorganic-rich cathode–electrolyte interface that preserves the cathode morphology, minimizes polarization during the critical H2 ↔ H3 phase transition, and significantly enhances bulk Li⁺ transport kinetics. Our findings provide experimental evidence of TMSB-VC synergy, which differs from a previously reported computational prediction, to demonstrate the effectiveness of TMSB as a cathode interface stabilizing additive when paired with VC.

Organic semiconductors present a promising alternative for solar-hydrogen production (SHP) due to their cost-effectiveness and environmentally friendly nature. However, their availability is limited, and they often exhibit lower efficiency than inorganic semiconductors. This inefficiency is primarily attributed to their intrinsic Frenkel excitons with high binding energy, which restrict charge separation and transport. This study explores hydrogen bonding interactions in donor–acceptor conjugated polymer heterojunctions (PHJs) incorporating mesoporous C₃N₅, C₃N₆, and C₃N₇ nanostructures. The fluorine (–F) atoms in poly(5,6-difluoro-4-methyl-7-(7-methyl-9,9-dioctyl-9H-fluoren-2-yl)benzo[c][1,2,5]thiadiazole) and the amino (−NH₂) groups in C₃N₅, C₃N₆, and C₃N₇ facilitate hydrogen bonding interactions, ensuring strong interfacial contact. These interactions enhance charge separation and light absorption, improving photocatalytic performance. Experimental results demonstrate that incorporating the donor unit into the polymer structure enhances light capture ability and improves charge transport. Among the tested materials, the strongest electron-donating donor–acceptor unit, poly(5,6-difluoro-4-methyl-7-(7-methyl-9,9-dioctyl-9H-fluoren-2 yl)benzo[c][1,2,5]thiadiazole), exhibits the highest light absorption and charge separation efficiency. This optimized structure significantly enhances SHP, achieving an impressive hydrogen evolution rate of 2992.7 μmol g^–1 h^–1. These findings provide valuable insights into the development of organic semiconductor-based photocatalysts, contributing to the advancement of renewable hydrogen production.

Solid oxide (SOFC/SOEC) and protonic ceramic (PCFC/PCEC) electrochemical cells are key enabling technologies for the future energy transition. These high- and intermediate-temperature devices offer exceptional efficiency and fuel flexibility, positioning them as critical components in decarbonizing sectors where low-temperature systems fall short. Chromium (Cr) poisoning remains one of the most critical degradation mechanisms limiting the performance, durability, and commercial viability of these solid oxide and protonic ceramic electrochemical cells (SOCs and PCCs). Cr volatilization from ferritic stainless steel interconnects and subsequent deposition of volatile Cr species such as CrO₃ and CrO₂(OH)₂ at the oxygen electrode lead to the formation of electrically insulating phases, which compromise triple-phase boundary (TPB) activity, increase polarization resistance, and accelerate performance degradation. While Cr-related degradation has been extensively studied in SOCs, its impact on PCCs, which are promising candidates for efficient hydrogen production remains comparatively underexplored. This review critically analyzes Cr poisoning mechanisms across these electrochemical systems, highlighting the mechanistic differences arising from their distinct configurations, ion conduction modes, and operating environments. Advances in material innovations, including Cr-resistant alloys, protective coatings, and improved electrode formulations, are discussed with a focus on their cross-system applicability and effectiveness. The need for predictive modeling, long-term durability studies, and system-level validation under realistic conditions is emphasized as essential for advancing Cr mitigation strategies. By consolidating current understanding and identifying key research gaps, this review outlines strategic directions for the development of Cr-resilient materials, optimized getter integration, and tailored protection schemes for the unique challenges posed by PCECs. Ultimately, it underscores the urgency of developing robust, scalable solutions to enable the reliable deployment of next-generation high-temperature electrolysis technologies in sustainable energy systems.

Solid-state batteries (SSBs) with lithium metal anodes offer exceptional energy density but suffer from dendrite growth and limited interfacial stability. Here, we report a poly(vinylidene fluoride-co-hexafluoropropylene)-based solid electrolyte incorporating hexagonal boron nitride (h-BN) as a multifunctional filler and lithium bis(trifluoromethanesulfonyl)imide as a salt to simultaneously enhance ionic conductivity and suppress dendrite formation. The optimized composition (3 wt % h-BN, PB3) achieves an ionic conductivity of 6.44 × 10^–4 S cm^–1 and a reduced electronic conductivity of 6.85 × 10^–9 S cm^–1. This balance enables stable lithium plating/stripping for over 200 h in symmetric cells and a capacity retention of ∼93% over 150 cycles in Li||LiNi_0.6Co_0.2Mn_0.2O₂ cells. Mechanistically, the insulating nature of h-BN and anion-trapping capability promote uniform Li-ion flux, mitigating localized dendrite nucleation. This dual functionality of h-BN offers a promising design pathway for safe, high-performance all-solid-state batteries.

The electrode fabrication process remains a critical stage in lithium-ion battery (LIB) manufacturing, where further advancements are needed to improve the energy efficiency and scalability. The conventional route relies on drying slurry-cast electrodes through circulating warm air, followed by vacuum postdrying, a practice that incurs high energy costs and involves multiple processing stages. Here, we investigate infrared (IR) drying to simplify electrode processing while tuning the binder structure at the molecular level. Lithium cobalt oxide (LCO) cathode slurry was cast onto a current collector and subjected to three drying conditions: (i) dried until visibly solvent-free, (ii) further IR-treated after reaching the solvent-free state, and (iii) vacuum-dried following the visibly solvent-free stage. Comprehensive characterization revealed that electrodes subjected to extended IR treatment exhibited superior mechanical adhesion, more effective solvent removal (negligible weight loss between 100 and 300 °C in thermogravimetric analysis), and lower internal resistance with a minimal increase after prolonged cycling, outperforming both counterparts despite the absence of observable morphological differences. Electrochemical testing further demonstrates that extended IR exposure achieves high-rate performance of 112 mAh g^–1 at 2 C and stable capacity retention for 500 cycles at C/3. Analysis of PVDF films prepared under comparable drying conditions confirmed that exposure near the melting temperature of the PVDF with extended IR treatment enhances crystallinity of α-phase, strengthening mechanical stability and improving electrochemical behavior of LCO cathodes. These results highlight IR drying as a practical route to control the binder structure, offering both energy savings and improved performance in LIB electrode manufacturing.