Energy & Environmental Materials最新文献

The increasing demand for high-capacity energy storage, spurred by the growth of renewable energy, has accelerated the pursuit of cost-effective and sustainable aqueous zinc-ion batteries as a viable alternative to traditional lithium-ion batteries. In this study, a cation-anion coordination cathode material (Zn-MnO₂F_X) is proposed, which regulates the central valence state of Mn ions by covalently anchoring manganese oxides with Zn ions and F ions to inhibit Jahn-Teller distortion and manganese dissolution. Density Functional Theory calculations elucidate the intercalation of Zn²⁺ extends the MnO₂ layer spacing, reduces ion diffusion barriers, and accelerates ion diffusion, while F⁻ ions repair defects and enhance the electronic conductivity of MnO₂, which stabilizes the cathodes and prolongs the life span of batteries. The co-insertion of Zn²⁺/H⁺ in MnO₂ and the auxiliary effect of Zn₄SO₄·(OH)₆·xH₂O on dissolution/deposition were elucidated by analyzing the changes in structure, morphology, and impedance during the cycling process. The Zn-MnO₂F_x cathode exhibits a high reversible capacity of 365.5 mA h g⁻¹ at 0.1 A g⁻¹, with remarkable capacity retention of 96.7% after 1000 cycles at 1 A g⁻¹. The initial specific capacity of the flexible yarn battery reaches 112.5 mA h g⁻¹ at 0.1 A g⁻¹. This work adeptly addresses the kinetic-stability balance in cathode materials, offering a pioneering strategy for sustainable and efficient large-scale energy storage.

High-entropy oxides (HEOs) have sparked scientific interest recently as a potential material technology for lithium-sulfur (Li–S) batteries. This interest stems from their simultaneous roles as sulfur hosts and electrocatalysts, which provide enhancements to the performance of sulfur cathode composites. Nonetheless, their incorporation into the active material blend results in compromised energy density, particularly when their gravimetric proportion is substantial (≥10 wt.%, in the sulfur-based cathode). In this study, a manganese (Mn)-containing HEO (S_config ≥ 1.5R) was synthesized and subsequently coated onto a commercial Celgard separator at a low areal loading (~0.23 mg cm⁻²) with the aim of decreasing HEO content in the cathode composite material while still boosting lithium polysulfide (LPS) conversion kinetics. Li–S batteries incorporating this modified separator-high entropy oxide (MS-HEO) demonstrate exceptional electrochemical performance, achieving a high initial discharge capacity of ~1642 mAh g⁻¹ at 0.1 C and a remarkably low-capacity fade rate of 0.055% per cycle over 450 cycles at 1 C. Remarkably, the MS-HEO batteries exhibited commendable electrochemical performance at high sulfur loading (~7 mg cm⁻²), delivering an initial discharge capacity of ~819 mAh g⁻¹ during the first discharge and maintaining stable cycling up to 30 cycles at 0.1 C thereafter. Collectively, this work underscores the significance of precise adjustment of HEO compositions through low-temperature MOF calcination strategies and demonstrates their potential to enhance the electrochemical performance of Li–S batteries under the high-sulfur loading conditions necessary for future commercial applications.

The present work reports on microscopic analyses of recombination at grain boundaries (GBs) in polycrystalline Li-doped (Ag,Cu)₂ZnSn(S,Se)₄ (Li-ACZTSSe) and Cu₂ZnSnS₄ (CZTS) absorber layers in high-efficiency solar cells (conversion efficiencies of 14.4% and 10.8%). Recombination velocities s_GB were determined at a large number of GBs by evaluating profiles extracted from cathodoluminescence intensity distributions across GBs in these polycrystalline layers. In both Li-ACZTSSe and CZTS absorber layers, the s_GB values exhibited wide ranges over several orders of magnitude with a median values of 680 and 1100 cm s⁻¹ for the Li-ACZTSSe and CZTS absorbers. A model that provides a comprehensive explanation for this finding is presented and discussed in detail. Correspondingly, wide ranges for s_GB can be explained by different positive or negative excess charge densities present at different GBs, leading to different downward or upward band bending on the order of several ±10 meV, provided that the net-doping density of the absorber layers is sufficiently large. As a result of the evaluation of the s_GB, input parameters for multidimensional device simulations are obtained. It is revealed that the grain boundary lifetime closely matches the overall effective lifetime, indicating that grain boundary recombination is a key factor limiting the effective carrier lifetime of both Li-ACZTSSe and CZTS absorbers. The estimated V_OC losses due to GBs reach up to 126 mV for Li-ACZTSSe and 88 mV for CZTS. This work highlights that reducing grain boundary recombination via improved passivation and increasing grain size is an effective strategy for achieving further efficiency improvements.

Constructing a nanostructure that combines abundant active edge sites with a well-designed heterostructure is an effective strategy for enhancing photocatalytic hydrogen generation. However, controllable approaches for creating heterostructures based on vertically standing transition metal dichalcogenide (TMD) nanosheets remain insufficient despite their potential for efficient hydrogen production. In this paper, we present efficient photocatalysts featuring heterojunctions composed of vertically grown TMD (MoS₂ and WS₂) nanosheets. These structures (WS₂, MoS₂, and MoS₂/WS₂ heterostructure) were fabricated using a controllable metal–organic chemical vapor deposition method, which expanded the surface area and facilitated effective photocatalytic hydrogen evolution. The vertical MoS₂/WS₂ heterostructures demonstrated significantly enhanced hydrogen generation, driven by the synergistic effects of improved light absorption, a large specific surface area, and appropriately arranged staggered heterojunctions. Furthermore, the photocatalytic activity was considerably influenced by the size and density of the vertical nanosheets. Consequently, the nanosheet size-tailored MoS₂/WS₂ heterostructure achieved a photocatalytic hydrogen generation rate (454.2 μmol h⁻¹ cm⁻²), which is 2.02 times and 2.19 times higher than that of WS₂ (225.6 μmol h⁻¹ cm⁻²) and MoS₂ (207.2 μmol h⁻¹ cm⁻²). Hence, the proposed strategy can be used to design staggered heterojunctions with edge-rich nanosheets for photocatalytic applications.

Graphene aerogels (GAs) exhibit exceptional potential in energy storage, particularly for high-capacity supercapacitors (SCs), owing to their unique three-dimensional (3D) porous structure, high conductivity, and mechanical stability. Despite limitations in electron transport and surface polarity, their performance can be enhanced through structural optimization and synthesis strategies. This review traces the evolution of GAs from 1931 to 2024, integrating historical development with recent breakthroughs. It analyzes the synergistic effects of synthesis methods (self-assembly, template-assisted) and drying techniques (freezing/supercritical/ambient-pressure drying), elucidating structure–performance relationships and electrochemical mechanisms. This review also details the current research status of GAs applied in double-layer capacitors and pseudocapacitors. It identifies existing issues and summarizes ways to improve performance. Additionally, the research prospects of AI-assisted and in situ dynamic characterization in the development of GAs are outlined. In conclusion, this review aims to further advance high-performance GA electrode materials for SC applications and to anticipate future technological trends, providing a basis and academic reference for researchers in the energy storage field.

Aqueous zinc-iodine batteries (AZIBs) have attracted significant attention as the most promising next-generation energy storage technology due to their low cost, inherent safety, and high energy density. However, their practical application is hindered by the poor electronic conductivity of iodine cathodes and the severe shuttling effect of intermediate polyiodides. Here, we report a novel micropores carbon framework (MCF) synthesized from waste coffee grounds via a facile carbonization-activation process. The resultant MCF features an ultrahigh specific surface area and a high density of micropores, which not only physically confine iodine species to minimize iodine loss but also enhance the electronic conductivity of the composite cathode. Furthermore, biomass-derived heteroatom dopings (nitrogen functionalities) facilitate effective chemical anchoring of polyiodide intermediates, thereby mitigating the shuttle effect. UV–visible spectroscopy and electrochemical kinetic analyses further confirm the rapid transformation and inhibition mechanism of iodine species by MCF. Consequently, the MCF/I₂ cathode delivers superior specific capacities of 238.3 mA h g⁻¹ at 0.2 A g⁻¹ and maintains outstanding cycling performance with a capacity retention of 85.2% after 1200 cycles at 1.0 A g⁻¹. This work not only provides an important reference for the design of high-performance iodine-host porous carbon materials but also explores new paths for the sustainable, high-value utilization of waste biomass resources.

The advantages of the Ge–Pb-based perovskite solar cells (PSCs), such as low bandgap, have made this kind of PSC popular nowadays. Nevertheless, they have adverse properties that need to be fixed, such as short lifetime and fast crystallization process, which causes Ge defects. In this research, the passivation of Ge defects by using pyridinium chlorochromate methylamine iodine (PCCMAI) in the perovskite film (PF) structure is investigated. By using PCCMAI, the PSC's performance enhancement and surface morphology optimization were observed. It is determined that by the reaction of PCCMAI in the perovskite solvent, a coordination polydentate is formed in Ge–Pb mixed perovskite, and it results in the improvement of crystallization quality and electron transfer. After PCCMAI treatment of the Ge–Pb-based perovskite film, the measured power conversion efficiency (PCE) indicates that the performance of the fabricated PSC increased from 16.85% to 20.14%. Moreover, fabricated PSCs show an increment in stability after PCCMAI treatment.

Layered manganese dioxide (δ-MnO₂) is considered a promising ammonium ion capture electrode material for capacitive deionization (CDI) attributed to its high theoretical capacity and cost-effectiveness. Nevertheless, it continues to encounter challenges including rapid capacity degradation, structural instability, and Jahn–Teller effect. Herein, a crystal and electron synergistically regulation engineering strategy is proposed for the suppression of the Jahn–Teller effect and the improvement of ammonium ion storage dynamics in F doped MnO₂ (MnOF). The induced action of F ions transforms the MnO₂ structure from the original cubic [MnO₆] octahedron into an asymmetric [Mn(OF)₆] octahedron with electron redistribution, and generates a localized charge imbalance along the O–Mn–F pathway, which promotes electron transfer from Mn to F direction, accelerates electron transfer, and reduces the energy barrier of ammonium ion diffusion. As a result, the prepared MnOF exhibited a maximum salt adsorption capacity of 144.3 mg g⁻¹ and an exceptionally high salt adsorption rate of 18.25 mg g⁻¹ min⁻¹, along with outstanding cycling stability. Besides, ex/in situ characterizations reveal that in MnOF, the formation/breaking of hydrogen bond is accompanied by the insertion/deinsertion of $��{\mathrm{NH}}_4^{+}�$. Therefore, the rational introduction of highly electronegative anions provides a new direction for the development of advanced CDI electrode materials.

Solid-state batteries are attracting considerable attention for their high-energy density and improved safety over conventional lithium-ion batteries. Among solid-state electrolytes, sulfide-based options like Li₆PS₅Cl are especially promising due to their superior ionic conductivity. However, interfacial degradation between sulfide electrolytes and high-voltage cathodes, such as LiCoO₂, limits long-term performance. This study demonstrates that a LiBF₄-derived F-rich coating on LiCoO₂, applied by immersing LiCoO₂ particles in a LiBF₄ solution followed by annealing, can significantly enhance performance in Li₆PS₅Cl-based solid-state batteries. This coating enables stable high-voltage (4.5 V vs Li⁺/Li) operation, achieving an initial specific capacity of 153.82 mAh g⁻¹ and 87.1% capacity retention over 300 cycles at 0.5C. The enhanced performance stems from the F-rich coating, composed of multiple phases including LiF, CoF₂, Li_xBF_yO_z, and Li_xBO_y, which effectively suppresses side reactions at the LiCoO₂|Li₆PS₅Cl interface and improves lithium-ion diffusivity, thereby enabling greater Li capacity utilization. Our findings provide a practical pathway for advancing solid-state batteries with high-voltage LiCoO₂ cathodes, offering substantial promise for next-generation energy storage systems.

In the global transition towards sustainable energy sources, hydrogen energy has emerged as an indispensable pillar in reshaping the energy landscape, owing to its environmental sustainability, zero emissions, and high efficiency. Nevertheless, the large-scale deployment of hydrogen energy is confronted with substantial technical barriers in storage and transportation. Although contemporary research has shifted focus to the development of highly efficient hydrogen storage materials, conventional material design concepts remain predominantly empirical, typically relying on trial-and-error methodologies. Importantly, the widespread application of artificial intelligence technologies in accelerating materials discovery and optimization has attracted considerable attention. This review provides a comprehensive overview of the latest advancements in hydrogen storage technologies, with an emphasis on the synergistic application of high-throughput screening and machine learning in solid-state hydrogen storage materials. These approaches demonstrate exceptional potential in accurately predicting hydrogen storage properties, optimizing material performance, and accelerating the development of innovative hydrogen storage materials. Specifically, we discuss in detail the essential role of artificial intelligence in developing hydrogen storage materials such as metal hydrides, alloys, carbon materials, metal–organic frameworks, and zeolites. Moreover, underground hydrogen storage is further explored as a scalable renewable energy storage solution, particularly in terms of optimizing storage parameters and performance prediction. By systematically analyzing the limitations of existing hydrogen storage approaches and the transformative potential of artificial intelligence-driven methods, this review offers insights into the discovery and optimization of high-performance hydrogen storage materials, contributing to sustainable global energy development and technological innovation.