能源化学最新文献

Optimizing charge migration and alleviating volume expansion in anode materials are the key to improve the electrochemical performance for sodium-ion storage devices. Herein, a hierarchical porous conducting matrix confining defect-rich selenium doped cobalt dichalcogenide (CoSe_0.5S_1.5/GA) is constructed as a promising SICs anode based on the guidance of theoretical calculation analysis. The increased defect concentration significantly enhanced the disorder degree of the compound and presented electron aggregation around the S atoms, which effectively modulated the electronic structure, further enabling high rate and ultra-capacity sodium storage. Moreover, strong interfacial coupling could construct spatial constraint to alleviate volume expansion as well as maintain electrode integrity and stability. The CoSe_0.5S_1.5/GA electrode can deliver a high capacity of 310.1 mA h g⁻¹ after 2000 cycles at 1 A g⁻¹, and the CoSe_0.5S_1.5/GA//AC sodium ion capacitor can exhibit an outstanding energy density of 237.5 W h kg⁻¹. A series of characterization and theoretical calculation convincingly reveal that the defect moieties can regulate the Na⁺ storage and diffusion kinetics, which prove that our defect manufacture coupling with space-confined strategy can provide deep insights into the development of high-performance Na⁺ storage devices.

Self-assembly of metal halide perovskite nanocrystals (NCs) into superlattices can exhibit unique collective properties, which have significant application values in the display, detector, and solar cell field. This review discusses the driving forces behind the self-assembly process of perovskite NCs, and the commonly used self-assembly methods and different self-assembly structures are detailed. Subsequently, we summarize the collective optoelectronic properties and application areas of perovskite superlattice structures. Finally, we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.

Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation. However, the effect of Nafion on electrocatalytic performance was often overlooked, especially for CO₂ electrolysis. Herein, the key roles of Nafion for CO₂RR were systematically studied on Cu nanoparticles (NPs) electrocatalyst. We found that Nafion modifier not only inhibit hydrogen evolution reaction (HER) by decreasing the accessibility of H₂O from electrolyte to Cu NPs, and increase the CO₂ concentration at electrocatalyst interface for enhancing the CO₂ mass transfer process, but also activate CO₂ molecule by Lewis acid-base interaction between Nafion and CO₂ to accelerate the formation of *CO, which favor of C–C coupling for boosting C₂ product generation. Owing to these features, the HER selectivity was suppressed from 40.6% to 16.8% on optimal Cu@Nafion electrode at −1.2 V versus reversible hydrogen electrode (RHE), and as high as 73.5% faradaic efficiencies (FEs) of C₂ products were achieved at the same applied potential, which was 2.6 times higher than that on bare Cu electrode (∼28.3%). In addition, Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction. Thus, this work provides insights into the impact of Nafion on electrocatalytic CO₂RR performance.

Zeolite-encapsulated metal nanoclusters are at the heart of bifunctional catalysts, which hold great potential for petrochemical conversion and the emerging sustainable biorefineries. Nevertheless, efficient encapsulation of metal nanoclusters into a high-silica zeolite Y in particular with good structural integrity still remains a significant challenge. Herein, we have constructed Ru nanoclusters (∼1 nm) encapsulated inside a high-silica zeolite Y (SY) with a SiO₂/Al₂O₃ ratio (SAR) of 10 via a cooperative strategy for direct zeolite synthesis and a consecutive impregnation for metal encapsulation. Compared with the benchmark Ru/H-USY and other analogues, the as-prepared Ru/H-SY markedly boosts the yields of pentanoic biofuels and stability in the direct hydrodeoxygenation of biomass-derived levulinate even at a mild temperature of 180 °C, which are attributed to the notable stabilization of transition states by the enhanced acid accessibility and properly sized constraints of zeolite cavities owing to the good structural integrity.

Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO₂ toward CH₄, yet a revealing insight into the reaction pathway and mechanism has remained elusive. Herein, we construct chemically bonded Ag-Cu₂O boundaries, in which the complete reduction of Cu₂O to Cu has been strongly impeded owing to the presence of surface Ag shell. The interfacial confinement effect helps to maintain Cu⁺ sites at the Ag-Cu₂O boundaries. Using in situ/operando spectroscopy and theoretical simulations, it is revealed that CO₂ is enriched at the Ag-Cu₂O boundaries due to the enhanced physisorption and chemisorption to CO₂, activating CO₂ to form the stable intermediate *CO. The boundaries between Ag shell and the Cu₂O mediate local *CO coverage and promote *CHO intermediate formation, consequently facilitating CO₂-to-CH₄ conversion. This work not only reveals the structure-activity relationships but also offers insights into the reaction mechanism on Ag-Cu catalysts for efficient electrocatalytic CO₂ reduction.

Direct growth of redox-active noble metals and rational design of multifunctional electrochemical active materials play crucial roles in developing novel electrode materials for energy storage devices. In this regard, silver (Ag) has attracted great attention in the design of efficient electrodes. Inspired by the house/building process, which means electing the right land, it lays a strong foundation and building essential columns for a complex structure. Herein, we report the construction of multifaceted heterostructure cobalt-iron hydroxide (CFOH) nanowires (NWs)@nickel cobalt manganese hydroxides and/or hydrate (NCMOH) nanosheets (NSs) on the Ag-deposited nickel foam and carbon cloth (i.e., Ag/NF and Ag/CC) substrates. Moreover, the formation and charge storage mechanism of Ag are described, and these contribute to good conductive and redox chemistry features. The switching architectural integrity of metal and redox materials on metallic frames may significantly boost charge storage and rate performance with noticeable drop in resistance. The as-fabricated Ag@CFOH@NCMOH/NF electrode delivered superior areal capacity value of 2081.9 µA h cm⁻² at 5 mA cm⁻². Moreover, as-assembled hybrid cell based on NF (HC/NF) device exhibited remarkable areal capacity value of 1.82 mA h cm⁻² at 5 mA cm⁻² with excellent rate capability of 74.77% even at 70 mA cm⁻² Furthermore, HC/NF device achieved maximum energy and power densities of 1.39 mW h cm⁻² and 42.35 mW cm⁻², respectively. To verify practical applicability, both devices were also tested to serve as a self-charging station for various portable electronic devices.

Higher nickel content endows Ni-rich cathode materials LiNi_xCo_yMn_1−x−yO₂ (x > 0.6) with higher specific capacity and high energy density, which is regarded as the most promising cathode materials for Li-ion batteries. However, the deterioration of structural stability hinders its practical application, especially under harsh working conditions such as high-temperature cycling. Given these circumstances, it becomes particularly critical to clarify the impact of the crystal morphology on the structure and high-temperature performance as for the ultrahigh-nickel cathodes. Herein, we conducted a comprehensive comparison in terms of microstructure, high-temperature long-cycle phase evolution, and high-temperature electrochemical stability, revealing the differences and the working mechanisms among polycrystalline (PC), single-crystalline (SC) and Al doped SC ultrahigh-nickel materials. The results show that the PC sample suffers a severe irreversible phase transition along with the appearance of microcracks, resulting a serious decay of both average voltage and the energy density. While the Al doped SC sample exhibits superior cycling stability with intact layered structure. In-situ XRD and intraparticle structural evolution characterization reveal that Al doping can significantly alleviate the irreversible phase transition, thus inhibiting microcracks generation and enabling enhanced structure. Specifically, it exhibits excellent cycling performance in pouch-type full-cell with a high capacity retention of 91.8% after 500 cycles at 55 °C. This work promotes the fundamental understanding on the correlation between the crystalline morphology and high-temperature electrochemical stability and provides a guide for optimization the Ni-rich cathode materials.

P2-Na_0.67Ni_0.33Mn_0.67O₂ (NNMO) is promising cathode material for sodium-ion batteries (SIBs) due to its high specific capacity and fast Na⁺ diffusion rate. Nonetheless, the irreversible P2-O2 phase transformation, Na⁺/vacancy ordering, and transition metal (TM) dissolution seriously damage its cycling stability and restrict its commercialization process. Herein, Na occupation manipulation and interface stabilization are proposed to strengthen the phase structure of NNMO by synergistic Zn/Ti co-doping and introducing lithium difluorophosp (LiPO₂F₂) film-forming electrolyte additive. The Zn/Ti co-doping regulates the occupancy ratio of Na_e/Na_f at Na sites and disorganizes the Na⁺/vacancy ordering, resulting in a faster Na⁺ diffusion kinetics and reversible P2-Z phase transition for P2-Na_0.67Ni_0.28Zn_0.05Mn_0.62Ti_0.05O₂ (NNZMTO). Meanwhile, the LiPO₂F₂ additive can form homogeneous and ultrathin cathode-electrolyte interphase (CEI) on NNZMTO surface, which can stabilize the NNZMTO-electrolyte interface to prevent TM dissolution, surface structure transformation, and micro-crack generation. Combination studies of in situ and ex situ characterizations and theoretical calculations were used to elucidate the storage mechanism of NNZMTO with LiPO₂F₂ additive. As a result, the NNZMTO displays outstanding capacity retention of 94.44% after 500 cycles at 1C with 0.3 wt% LiPO₂F₂, excellent rate performance of 92.5 mA h g⁻¹ at 8C with 0.1 wt% LiPO₂F₂, and remarkable full cell capability. This work highlights the important role of manipulating Na occupation and constructing protective film in the design of layered materials, which provides a promising direction for developing high-performance cathodes for SIBs.

Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density. However, they suffer from short lifespan and extreme safety concerns, which are attributed to the degradation of layered oxides and the decomposition of electrolyte at high voltage, as well as the high reactivity of metallic Li. The key is the development of stable electrolytes against both high-voltage cathodes and Li with the formation of robust interphase films on the surfaces. Herein, we report a highly fluorinated ether, 1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy) methoxy] ethane (TTME), as a co-solvent, which not only functions as a diluent forming a localized high concentration electrolyte (LHCE), but also participates in the construction of the inner solvation structure. The TTME-based electrolyte is stable itself at high voltage and induces the formation of a unique double-layer solid electrolyte interphase (SEI) film, which is embodied as one layer rich in crystalline structural components for enhanced mechanical strength and another amorphous layer with a higher concentration of organic components for enhanced flexibility. The Li||Cu cells display a noticeably high Coulombic efficiency of 99.28% after 300 cycles and Li symmetric cells maintain stable cycling more than 3200 h at 0.5 mA/cm² and 1.0 mAh/cm². In addition, lithium metal cells using LiNi_0.8Co_0.1Mn_0.1O₂ and LiCoO₂ cathodes (both loadings ∼3.0 mAh/cm²) realize capacity retentions of >85% over 240 cycles with a charge cut-off voltage of 4.4 V and 90% for 170 cycles with a charge cut-off voltage of 4.5 V, respectively. This study offers a bifunctional ether-based electrolyte solvent beneficial for high-voltage Li metal batteries.

The reliable prediction of state of charge (SOC) is one of the vital functions of advanced battery management system (BMS), which has great significance towards safe operation of electric vehicles. By far, the empirical model-based and data-driven-based SOC estimation methods of lithium-ion batteries have been comprehensively discussed and reviewed in various literatures. However, few reviews involving SOC estimation focused on electrochemical mechanism, which gives physical explanations to SOC and becomes most attractive candidate for advanced BMS. For this reason, this paper comprehensively surveys on physics-based SOC algorithms applied in advanced BMS. First, the research progresses of physical SOC estimation methods for lithium-ion batteries are thoroughly discussed and corresponding evaluation criteria are carefully elaborated. Second, future perspectives of the current researches on physics-based battery SOC estimation are presented. The insights stated in this paper are expected to catalyze the development and application of the physics-based advanced BMS algorithms.