Energy & Environmental Science最新文献

Pseudocapacitive materials store electrochemical energy through fast and reversible surface charge transfer reactions. Titanium carbide MXenes are two-dimensional materials which have shown redox or intercalation pseudocapacitive properties depending on the electrolyte. Nevertheless, the intrinsic pseudocapacitive charging mechanism in individual MXene flakes remains unresolved. Here, we employ in situ scanning transmission X-ray microscopy (STXM) to map the local chemical changes in individual Ti₃C₂T_x MXene flakes during spontaneous and electrochemical intercalation of protons and lithium ions in aqueous electrolytes. Our investigations reveal that proton and lithium-ion intercalation induces a reduction and an oxidation, respectively, of the titanium atoms in the MXene. This difference reveals a profoundly different chemical origin between redox and intercalation pseudocapacitive processes. By elucidating the interplay between ion hydration, MXene surface chemistry and flake morphology, our study highlights the relevance of chemical imaging in single entities for the fundamental understanding of electrochemical charge storage mechanisms.

Dimerized M-series small-molecule acceptors feature highly planar conjugated backbones, enabling ordered stacking and enhanced morphological stability. However, rotatable bonds introduced during dimerization often induce conformational disorder, undermining efficient charge generation and transport. Here, we report two rationally designed M-series dimers, DM-TF and DMF-T, which both incorporate strategic intramolecular fluorine⋯hydrogen interactions to enhance conformational rigidity. DM-TF, which features fluorinated thiophene π-bridges interacting with hydrogen atoms on the central end groups, exhibits superior conformational rigidity, reduced energetic disorder, improved crystallinity, and enhanced charge transport properties compared to DMF-T. Consequently, DM-TF-based organic solar cells (OSCs) deliver a power conversion efficiency of 18.40%, surpassing the DMF-T-based devices (17.77%). Additionally, they demonstrate exceptional thermal stability, exhibiting negligible performance loss after being heated at 80 °C for 2000 hours. Furthermore, incorporating DM-TF as a third component into PM6:M36 blends boosts the efficiency of the resulting devices to 19.16%, which is the highest reported value among all non-Y-series acceptors. These results underscore the effectiveness of engineering intramolecular non-covalent interactions in the molecular design of acceptor materials and highlight the great potential of dimerized M-series acceptors for high-efficiency and stable OSCs.

Efficient metal-free catalysts are crucial for advancing aluminum–air batteries (AABs), yet their development has been hindered by poor electronic structure optimization and sluggish mass transport. In this study, we developed a hierarchically porous N/S co-doped carbon nanoreactor via an etching-doping pyrolysis strategy, achieving an ultrahigh surface area of 2630 m² g⁻¹ and a well-organized pore network. The resulting catalyst demonstrated outstanding oxygen reduction reaction (ORR) activity, with half-wave potentials of 0.952 V (vs. RHE; RHE stands for reversible hydrogen electrode) in alkaline and 0.754 V (vs. RHE) in acidic media. When assembled into AABs, it delivered a peak power density of 265 mW cm⁻² and an energy density of 4152 Wh kg⁻¹, along with excellent cycling stability. Finite element simulations showed that the hierarchical porosity promoted oxygen diffusion and enhanced reaction kinetics. Furthermore, in situ characterization and theoretical calculations revealed that S–C–N configurations dynamically transformed into O_pre–S–C–N groups under working conditions, which modulated the electronic structure of adjacent carbon sites, facilitated *O-to-*OH conversion, and reduced energy barriers. This study provided a dynamic site-regulation strategy for improving ORR kinetics in metal-free catalysts and offered a new pathway for designing high-performance energy materials operating under realistic conditions.

In aqueous zinc (Zn) metal secondary batteries, some interfacial side reactions, such as the hydrogen evolution reaction (HER), anode corrosion and dendrite growth, often lead to short circuit and cycling performance deterioration. Here we select four kinds of amino acid monomers (i.e., lysine, glutamate, cysteine and phenylalanine) with different polarity side chain groups to tailor pentapeptides, successfully constructing a thermodynamically stable colloid dispersion electrolyte system with the Tyndall effect for Zn metal secondary batteries. The proposed electrolyte system composed of the tailored lysine pentapeptide (LP) effectively suppresses Zn dendrite growth through regulating the (002) crystalline plane orientation. Furthermore, the LP has strong attraction towards H₂O molecules, thereby achieving desolvation of Zn²⁺ ions and reducing anode corrosion as well as the HER. In this LP-based colloid dispersion electrolyte, the Zn//Zn symmetric cell demonstrated an unprecedented ultralong cycling time beyond 10 000 hours (416 days) at 2 mA cm⁻². The developed Zn-ion pouch cells with a high cathode mass loading of ∼ 28.7 mg cm⁻² displayed a capacity retention of ∼83.7% after 1000 cycles at 0.5 A g⁻¹, which is superior to most recently reported zinc-ion pouch cells. The proposed thermodynamically stable colloid dispersion electrolyte is a new aqueous electrolyte system for economical, safe and long-lifespan Zn metal secondary batteries.

The synergistic regulation of steam utilization and proton transport at the oxygen electrode is crucial for proton ceramic electrolysis cells (PCECs). Ruddlesden–Popper (RP) perovskites leverage interlayer water intercalation features to achieve rapid proton uptake even under low-steam conditions. Herein, an RP-type oxygen electrode capable of reversible phase transitions and hydrated oxyhydroxide formation under high-temperature steam was constructed, successfully transcending the hydration limits of single perovskites. By integrating the structural analysis employing microcrystal electron diffraction (MicroED) and density functional theory (DFT) calculations, it is revealed that the interlayer proton-trapping sites significantly boost the steam adsorption/hydration and lower the energy barrier for proton migration across layers. The Sr₃(Co_0.8Fe_0.1Nb_0.1)₂O_7−δ (SCFN-RP) electrode demonstrates excellent catalytic activity, reaching 1.01 A cm⁻²@1.3 V at 550 °C. This work emphasizes the crucial role of reversible hydrated oxyhydroxides in RP perovskites and offers a novel conception for the design of high-performance oxygen electrodes for PCECs.

Film capacitors are indispensable in electrical engineering; however, balancing the insulation and thermal stability of polymer dielectrics remains a key challenge for high-temperature energy storage. Aromatic polyimide (PI) exhibits a high glass transition temperature (T_g, >300 °C), facilitating the formation of charge transfer complexes (CTCs). Semi-aromatic PIs mitigate this order, but insufficient thermal stability leads to poor performance above 200 °C. To resolve this contradiction, we incorporated a sp³-centered monomer, tris(4-aminophenyl)methane (TAPM), into a semi-aromatic PI (MPD-PI), constructing a spatially disordered architecture that suppresses short-range π–π stacking and CTCs, enhancing dielectric insulation and thermal stability. The resulting copolymer specifically achieves a discharged energy density of 7.13 J cm⁻³ at 200 °C with 90% efficiency and 5.18 J cm⁻³ at 250 °C, representing 341% and 280% improvements compared to those of MPD-PI, respectively. The improved thermal stability also imparts excellent cycling stability (3 × 10⁵ cycles at 200 °C and 300 MV m⁻¹) and a state-of-the-art breakdown strength of 596.2 MV m⁻¹ at 250 °C. The conformational-engineering strategy of this work provides a versatile route for high-temperature polymer dielectrics.

The rapid growth of electric vehicles (EVs) is driving an urgent demand for lithium-ion batteries (LIBs) with higher specific energy, longer life, and uncompromised safety. Ni-rich layered oxides (LiNi_xC_oyMn_(1−x−y)O₂, x ≥ 0.8) have emerged as leading cathode materials for next-generation LIBs, owing to their high capacity and energy density. Further increasing Ni content is essential for improved performance and cost reduction. However, it also introduces new obstacles, necessitating thoughtful design of cathode composition, morphology, and microstructure, as well as the development of electrolyte formulations. In this review, we discuss the multiple failure mechanisms of Ni-rich cathodes in terms of two major aspects: structural degradation and gas release. We elucidate the key factors contributing to chemical, crystallographic, and microstructural degradation in Ni-rich cathodes, and summarize the various origins of gas evolution associated with these materials. Another key theme of this review is the modification of Ni-rich cathodes to address the practical hurdles that limit their use in long-range and high-safety EVs. Accordingly, we present a comprehensive overview of the latest Ni-rich cathode modification strategies for next-generation EV platforms.

Correction for ‘Ion exchange-induced Li_xMg_yBO_z coating synergized with reinforced bulk doping enables fast-charging long-cycling high-voltage LiCoO₂’ by Ting Wang et al., Energy Environ. Sci., 2025, 18, 10444–10459, https://doi.org/10.1039/d5ee04240b.