Angewandte Chemie International Edition最新文献

Lithium iron phosphate (LFP)/graphite batteries have long dominated the energy storage battery market and are anticipated to become the dominant technology in the global power battery market. However, the poor fast-charging capability and low-temperature performance of LFP/graphite batteries seriously hinder their further spread. These limitations are strongly associated with the interfacial lithium (Li)-ion transport. Here we report a wide-temperature-range ester-based electrolyte that exhibits high ionic conductivity, fast interfacial kinetics and excellent film-forming ability by regulating the anion chemistry of Li salt. The interfacial barrier of the battery is quantitatively unraveled by employing three-electrode system and distribution of relaxation time technique. The superior role of the proposed electrolyte in preventing Li⁰ plating and sustaining homogeneous and stable interphases are also systematically investigated. The LFP/graphite cells exhibit rechargeability in an ultrawide temperature range of -80 °C to 80 °C and outstanding fast-charging capability without compromising lifespan. Specially, the practical LFP/graphite pouch cells achieve 80.2 % capacity retention after 1200 cycles (2 C) and 10-min charge to 89 % (5 C) at 25 °C and provide reliable power even at -80 °C.

Activating metal ion-doped oxides as visible-light-responsive photocatalysts requires intricate structural and electronic engineering, a task with inherent challenges. In this study, we employed a solid (template)-molten (dopants) reaction to synthesize Bi- and Rh-codoped SrTiO₃ (SrTiO₃ : Bi,Rh) particles. Our investigation reveals that SrTiO₃ : Bi,Rh manifests as single-crystalline particles in a core (undoped)/shell (doped) structure. Furthermore, it exhibits a well-stabilized Rh³⁺ energy state for visible-light response without introducing undesirable trapping states. This precisely engineered structure and electronic configuration promoted the generation of high-concentration and long-lived free electrons, as well as facilitated their transfer to cocatalysts for H₂ evolution. Impressively, SrTiO₃ : Bi,Rh achieved an exceptional apparent quantum yield (AQY) of 18.9 % at 420 nm, setting a new benchmark among Rh-doped-based SrTiO₃ materials. Furthermore, when integrated into an all-solid-state Z-Scheme system with Mo-doped BiVO₄ and reduced graphene oxide, SrTiO₃ : Bi,Rh enabled water splitting with an AQY of 7.1 % at 420 nm. This work underscores the significance of simultaneous structural and electronic engineering and introduces the solid-molten reaction as a viable approach for this purpose.

Helical nanostructures fabricated via the self-assembly of artificial motifs have been a captivating subject because of their structural aesthetics and multiple functionalities. Herein, we report the facile construction of a self-assembled nanohelix (NH) by leveraging an achiral aggregation-induced emission (AIE) luminogen (G) and pillar[5]arene (H), driven by host-guest interactions and metal coordination. Inspired by the "sergeants and soldiers" effect and "majority rule" principle, the host-guest complexation between G and H is employed to fixate the twisted conformation of G for the generation of "contortion sites", which further induced the emergence of helicity as the 1D assemblies are formed via Ag(I) coordination and hexagonally packed into nano-sized fibers. The strategy has proved feasible in both homogeneous and heterogeneous syntheses. Along with the formation of NH, boosted luminescence and enhanced productivity of reactive oxygen species (ROS) are afforded because of the efficient restriction on G, indicating the concurrent regulation of NH's morphology and photophysical properties by supramolecular assembly. In addition, NH also exhibits the capacity for bacteria imaging and photodynamic antibacterial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

Stable organic radicals generated by photo-excitation hold applications in molecular switching devices and information storage. It remains challenging to develop photo-generated radical materials with rapid response and air stability in the solid state. Here, we report a structure based on 1,3,6,8-tetraphenylpyrene derivative (Py-TTAc) displaying photo-induced radicals with air stability in the solid state. Photo-induced electron transfer, exposed to a 365 nm ultraviolet lamp for 1 minute, affords radicals in Py-TTAc powder as confirmed by electron paramagnetic resonance (EPR) spectroscopy. The maximum radical concentration reaches 2.21 % after continuous irradiation for 1 hour and recurs more than 10 times without any chemical degradation. The mechanistic study according to the femtosecond transient absorption (fsTA) and X-ray technology suggests that the radicals are derived from photo-induced symmetry-breaking charge separation (SB-CS) and stabilized through non-covalent interactions. The photo-generated stable radical system is employed in anti-counterfeiting paper and optoelectronic device applications. This study will provide insights into the development of photoactive organic radical materials.

The preparation of polyolefins with high polar monomer contents (above 20 mol %) has long been a challenge. Half-titanocenes (Cp')[HCN(Ar)]₂BOTiCl₂ bearing bulky electron-donating N-heterocyclic boryloxy ligands have been designed and synthesized. The complexes (Cp*)[HCN(Ar)]₂BOTiCl₂ (2, Ar=2,6-iPr₂C₆H₃; 5, Ar=2,4,6-Me₃C₆H₂) supported by Cp* and the boryloxy ligands have been shown to efficiently catalyze the copolymerization of ethylene and long chain α-olefins. In particular, precatalyst 5 enabled the controlled synthesis of poly(ethylene-co-9-decen-1-ol) with unprecedented high polar monomer contents up to 32.1 mol % while maintaining the high catalytic activity. The structural analysis and DFT calculations disclosed that the bulky and strong electron-donating boryloxy ligands could effectively stabilize cationic active species. The mechanical studies on the hydroxyl-functionalized copolymers disclosed that they exhibited high strength and toughness because of the existence of hydrogen bonds in the polymer network.

Metal-free covalent organic frameworks (COFs) are employed in oxygen reduction reactions (ORR) because of their diverse structural units and controllable catalytic sites, and the edge sites have high catalytic activity than the basal sites. However, it is still challenge to modulate the edge sites in COFs, because the extended frameworks in two- or three-dimensional topologies resulted in limited edge parts. In this study, we have demonstrated the edge site modulation engineering based on one dimensional (1D) COFs to catalyze the ORR, which featured distinct edge groups-carbonyl, diaminopyrazine, phenylimidazole, and benzaldehyde imidazole units. The synthesized COFs have same ordered frameworks, similar pore structure, but had different electronic states of the carbons along the edge sites, which results in tailored catalytic properties. Notably, the COF functionalized with a phenylimidazole edge group exhibited superior catalytic performance compared to the other synthesized COFs. And the theoretical calculation further revealed the different edge sites had tunable binding ability of the intermediates OOH*, which contributed modulated activity. Our findings introduce a novel way for designing COFs optimized for ORR applications through molecular level control of edge sites.

Developing high-performance lithium-sulfur batteries is a promising way to attain higher energy density at a lower cost beyond the state-of-the-art lithium-ion battery technology. However, the major issues impeding their practical applications are the sluggish kinetics and the parasitic shuttling reactions of sulfur and polysulfides. Here, pillaring the multilayer graphene membrane with a metal-organic framework (MOF) demonstrates the substantial impact of a versatile interlayer design in tackling these issues. Unlike regular composite separators reported so far, the participation of tri-metallic Ni-Co-Mn MOF as pillars supports the construction of an ion-channel interconnected interlayer structure, unexpectedly balancing the interfacial concentration polarization, spatially confining the soluble polysulfides, and vastly affording the lithiophilic sites for highly efficient polysulfide sieving/conversion. As a demonstration, we show that the MOF-pillared interlayer structure enables outstanding capacity (1634 mAh g^-1 at 0.1 C) and longevity (average capacity decay of 0.034 % per cycle in 2000 cycles) for lithium-sulfur batteries. Besides, the multilayer separator can be readily integrated into the high-nickel cathode (LiNi_0.91Mn_0.03Co_0.06O₂)-based lithium-ion batteries, which efficiently suppresses the undesired phase evolution upon cycling. These findings suggest the potential of "gap-filling" materials in fabricating multi-functional separators, bringing forward the pillared interlayer structure for energy-storage applications.

Directly converting CO₂ in flue gas using artificial photosynthetic technology represents a promising green approach for CO₂ resource utilization. However, it remains a great challenge to achieve efficient reduction of CO₂ from flue gas due to the decreased activity of photocatalysts in diluted CO₂ atmosphere. Herein, we designed and synthesized a series of dual metallosalen-based covalent organic frameworks (MM-Salen-COFs, M: Zn, Ni, Cu) for artificial photosynthetic diluted CO₂ reduction and confirmed their advantage in comparison to that of single metal M-Salen-COFs. As a results, the ZnZn-Salen-COF with dual Zn sites exhibits a prominent visible-light-driven CO₂-to-CO conversion rate of 150.9 μmol g^-1 h^-1 under pure CO₂ atmosphere, which is ~6 times higher than that of single metal Zn-Salen-COF. Notably, the dual metal ZnZn-Salen-COF still displays efficient CO₂ conversion activity of 102.1 μmol g^-1 h^-1 under diluted CO₂ atmosphere from simulated flue gas conditions (15 % CO₂), which is a record high activity among COFs- and MOFs-based photocatalysts under the same reaction conditions. Further investigations and theoretical calculations suggest that the synergistic effect between the neighboring dual metal sites in the ZnZn-Salen-COF facilitates low concentration CO₂ adsorption and activation, thereby lowering the energy barrier of the rate-determining step.

Unstable interphase formed in conventional carbonate-based electrolytes significantly hinders the widespread application of lithium metal batteries (LMBs) with high-capacity nickel-rich layered oxides (e.g., LiNi_0.8Co_0.1Mn_0.1O₂, NCM811) over a wide temperature range. To balance ion transport kinetics and interfacial stability over wide temperature range, herein a bifunctional electrolyte (EAFP) tailoring the electrode/electrolyte interphase with 1,3-propanesultone as an additive was developed. The resulting cathode-electrolyte interphase with an inorganic inner layer and an organic outer layer possesses high mechanical stability and flexibility, alleviating stress accumulation and maintaining the structural integrity of the NCM811 cathode. Meanwhile, the inorganic-rich solid electrolyte interphase inhibits electrolyte side reactions and facilitates fast Li⁺ transport. As a result, the Li||Li cells exhibit stable performance in extensive temperatures with low overpotentials, especially achieving a long lifespan of 1000 h at 30 °C. Furthermore, the optimized EAFP is also suitable for LiFePO₄ and LiCO₂ cathodes (1000 cycles, retention: 67 %). The Li||NCM811 and graphite||NCM811 pouch cells with lean electrolyte (g/Ah grade) operate stably, verifying the broad electrode compatibility of EAFP. Notably, the Li||NCM811 cells can operate in wide climate range from -40 °C to 60 °C. This work establishes new guidelines for the regulation of interphase by electrolytes in all-weather LMBs.