ACS Energy Letters 最新文献

Low-Ir electrocatalysts are crucial for developing large-scale polymer-electrolyte-membrane water electrolysis (PEMWE) facilities, which are necessary to advance the hydrogen economy. However, the performance and durability of low-Ir electrocatalysts are unsatisfactory. To address this issue, we prepared selenium-modified Ir nanoparticles on high-crystalline-carbon (HCC) supports. The introduction of HCC supports effectively reduced Ir usage, and Se incorporation mitigated Ir degradation. Se nucleophiles suppressed the electrochemical oxidation of Ir, leading to the formation of a unique nanostructure featuring an ultrathin IrO_xH_ySe_z shell and a crystalline Ir core. Theoretical calculations indicated that the electronic structure of Ir and its binding affinity with *O were modified, thereby enhancing the catalytic activities. Ir-IrO_xH_ySe_z/HCC exhibited outstanding PEMWE performances (Ir-mass specific power of 23.69 kW·gIr^–1; durability for 370 h) with a small amount of Ir (0.05 mg·cm^–2). Thus, employing a carbon support and nucleophile-induced nanostructures can serve as a strategy to ensure long-term PEMWE performance while reducing Ir usage.

Materials synthesis is a critical step in the development of energy storage technologies, from the first synthesis of newly predicted materials to the optimization of key properties for established materials. While the synthesis of solid-state materials has traditionally relied on intuition-driven trial-and-error, computational approaches are now emerging to accelerate the identification of improved synthesis recipes. In this Perspective, we explore these techniques and focus on their ability to guide precursor selection for solid-state synthesis. The applicability of each method is discussed in the context of materials for batteries, including Li-ion cathodes and solid electrolytes for all-solid-state batteries. Our analysis showcases the effectiveness of these computational methods while also highlighting their limitations. Based on these findings, we provide an outlook on future developments that can address existing limitations and make progress toward synthesis-by-design for battery materials.

A challenge for lithium lanthanum zirconate (LLZO)-based solid-state batteries is to increase the critical current density (CCD) to enable high current cycling. A promising strategy is to modify the LLZO surface morphology to provide a larger contact area with the Li metal. Here, a surface-textured thin LLZO electrolyte was prepared through an easily scalable process. The texturing process is a simple pressing of green LLZO tapes between micro-textured substrates. A variety of textures can be produced, depending on the type of substrate, and texturing can be on either one side or both sides. For this work, after pressing and sintering, several micro-patterns are formed on thin LLZO (∼118 μm thick). The properties of the various samples were characterized to investigate the impact of surface texturing, and the most promising ones were selected for electrochemical testing in symmetrical lithium cells and full cells. Li symmetric cells using a coarse ridge-textured LLZO exhibit ∼2.5 times increased CCD compared to planar non-textured LLZO, and a solid-state full cell shows stable cycling and improved rate performance. We believe this process offers a favorable trade-off of processing complexity vs structural optimization to maximize CCD.

Li-O₂ batteries (LOBs), with their high theoretical energy density, are seen as the prime candidates for post-lithium-ion battery development to address the increasing energy demand. The performance of LOBs is primarily determined by the formation and decomposition behavior of their discharge product, lithium peroxide (Li₂O₂), formed at the triple-phase boundary (TPB) among Li⁺, e^–, and O₂. Traditional electrodes, however, have a limited TPB area, which restricts Li₂O₂ generation and lowers the energy density. In this study, a unique dual-sided electrode configuration, designed to extend the TPB, was suggested. By applying an active material slurry on both sides of the gas diffusion layer, this configuration enhances mass transfer and facilitates the nucleation/decomposition of Li₂O₂. Such improvements lead to increased capacity and better cyclic reversibility, effectively addressing the trade-off between capacity and efficiency. These findings highlight the crucial role of an extended TPB in boosting the reversibility and energy density of LOBs.

Mechanically stacked, tandem thermophotovoltaic (TPV) cells featuring integrated air-bridge InGaAs and InGaAsP subcells achieve high spectral efficiency and emission temperature versatility. Thermocompression bonding of electrodes on opposing single air-bridge cells increases out-of-band reflectance (R_OUT) compared to cells lacking air bridges. We report a 0.74/0.74 eV homotandem exhibiting R_OUT = 96.4%. When operated in a multiterminal arrangement, the homotandem achieves 38% efficiency, marking a 20% absolute improvement over a comparable two-terminal configuration. We also demonstrate a 0.9/0.74 eV heterotandem with R_OUT = 97.2% and spectral efficiency approaching 80%. By minimizing losses associated with parasitic absorption and current mismatch, the tandem substantially expands the emission temperature range while preserving high efficiency. This leads to a reduction in the cost of energy storage by over 40%. The air-bridge tandem technology paves the way for high-performance tandem cells compatible with a variety of heat sources unrestricted by the choice of subcell materials.

The redox-matched flow battery (RMFB), which reversibly exchanges charge between a flowable redox mediator and stationary redox-active polymeric beads, has emerged as a viable technology for energy storage. However, RMFBs suffer from an underutilized charge capacity. In this work, we show that lower ionic strength solutions lead to significant increases in the charge capacity of ferrocene-functionalized beads in RMFBs. Single-particle experiments using scanning electrochemical cell microscopy (SECCM) showed that voltammetric peaks associated with the ferrocene redox dramatically increased in intensity (∼7-fold) as the ionic strength was decreased from 1000 to 10 mM of tetrabutylammonium hexafluorophosphate (TBAPF₆) in propylene carbonate. This change was accompanied by an increase in the particle size. Furthermore, higher performance (∼92% theoretical capacity utilization) was observed in RMFB cycling at 10 mM TBAPF₆ compared to 57% at 1000 mM TBAPF₆. Our results highlight the critical role of supporting electrolyte concentration in polymer-bead-based redox-matched flow batteries.

Zinc (Zn) powder-based anodes have garnered considerable attention as viable alternatives to their conventional Zn foil-based counterparts. However, challenges arising from undesirable interfacial side reactions and dendritic Zn growth hinder their practical implementation. Here, we present a class of liquid metal-skinned Zn (LSZ) powder anodes enabled by capillary suspension. The capillary suspension strategy can overcome the miscibility of liquid metal with other components, resulting in the self-standing and uniform LSZ powder anode. The nanothick eutectic gallium–indium (EGaIn) skin layer on Zn powders facilitated the horizontal growth of Zn along the (002) plane and mitigated Zn corrosion and hydrogen evolution reaction. Consequently, a full cell (V₂O₅ cathode ∥ LSZ powder anode) exhibited a stable capacity retention per cycle of 99.99% over 2000 cycles at a fast current rate of 1 A g^–1, outperforming those of previously reported aqueous Zn full cells.

Zinc–iodine (Zn–I₂) batteries hold great promise for high-performance, low-cost electrochemical energy storage, but their practical application faces thorny challenges associated with polyiodide shuttling and insufficient cycling stability. Herein, we propose molecular catalysis for long-life Zn–I₂ batteries, employing Hemin as an efficient and stable molecular catalyst. The Hemin molecules containing pentacoordinated iron sites significantly adsorb polyiodides, improve the conversion kinetics of iodine species, reduce triiodide concentration, and suppress polyiodide shuttling. Benefiting from molecular catalysis, the Zn–I₂ batteries demonstrate an exceptional cycling life, exceeding 62000 cycles with only 0.00052% decay per cycle while maintaining discharge voltage plateaus. The pivotal function of molecular catalysis in both the adsorption and conversion of polyiodide species shows its significant impact on improving the cycling lifespan of Zn–I₂ batteries toward long-life energy storage.

Perovskite colloidal nanocrystals (PeNCs) have exceptional optoelectronic properties and phase stability, making them promising for photovoltaic applications. However, insulating ligands on PeNC surfaces limit the current density and reduce the power conversion efficiency (PCE) in PeNC solar cells (SCs). This study introduces an amine-assisted ligand-exchange (ALE) strategy using 3-phenyl-1-propylamine (3P1P) to effectively remove long ligands from PeNC films. ALE reduced long-chain ligand density without increasing the number of defect states and therefore reduced the exciton-binding energy of FAPbI₃ NC films. These changes facilitated exciton dissociation and charge transport in FAPbI₃ PeNC SCs. The facilitation of exciton dissociation was due to the increased magnetic dipole interaction between excitons after the ALE process. The use of ALE achieved FAPbI₃ PeNC SCs that had an improved short-circuit current density of 17.98 mA/cm² and a PCE of 15.56% with improved stability after the treatment and negligible hysteresis. This work provides new insight into engineering PeNC films.

The key challenges for the industrial electrolysis of CO₂ into CO are the low CO₂ conversion, restricted scale-up, and poor long-term operation. Systematic process design and electrolyzer engineering are essential for addressing these challenges and exploiting the full potential of commercial CO₂ electrolysis. In this study, we employed a bipolar membrane (BPM) in a pressurized electrolyzer with a 25 cm² active area to achieve a maximum FE_CO of 93% with a cell voltage of 3.5 V and a maximum CO₂ single-pass conversion of 70% without detecting CO₂ crossover. In addition, we upscaled the system active area from 5 to 250 cm² and showed that this increase did not result in a loss of performance. In particular, the performance on the pressurized 100 cm² electrolyzer established an average FE_CO of 85% with a CO₂ single-pass conversion of 60% for over 120 h. This provides practical approaches for transitioning from laboratory-scale to industrial-scale electrolysis.