查看更多>>摘要：Lithium-sulfur(Li-S)batteries are considered highly promising as next-generation energy storage sys-tems due to high theoretical capacity(2600 W h kg-1)and energy density(1675 mA h g-1)as well as the abundant natural reserves,low cost of elemental sulfur,and environmentally friendly properties.However,several challenges impede its commercialization including low conductivity of sulfur itself,the severe"shuttle effect"caused by lithium polysulfides(LiPSs)during charge-discharge processes,vol-ume expansion effects and sluggish reaction kinetics.As a solution,polar metal particles and their com-pounds have been introduced as the main hosts for sulfur cathode due to their robust catalytic activity and adsorption capability,effectively suppressing the"shuttle effect"of LiPSs.Bimetallic alloys and their compounds with multi-functional properties exhibit remarkable electrochemical performance more readily when compared to single-metal materials.Well-designed bimetallic materials demonstrate larger specific surface areas and richer active sites,enabling simultaneous high adsorption capability and strong catalytic properties.The synergistic effect of the"adsorption-catalysis"sites accelerates the adsorption-diffusion-conversion process of LiPSs,ultimately achieving a long-lasting Li-S battery.Herein,the latest progress and performance of bimetallic materials in cathodes,separators,and interlayers of Li-S batteries are systematically reviewed.Firstly,the principles and challenges of Li-S batteries are briefly analyzed.Then,various mechanisms for suppressing"shuttle effects"of LiPSs are emphasized at the microscale.Subsequently,the performance parameters of various bimetallic materials are comprehensively summa-rized,and some improvement strategies are proposed based on these findings.Finally,the future pro-spects of bimetallic materials are discussed,with the hope of providing profound insights for the rational design and manufacturing of high-performance bimetallic materials for LSBs.
查看更多>>摘要：The scarcity,high cost and susceptibility to CO of Platinum severely restrict its application in alkaline hydrogen oxidation reaction(HOR).Hybridizing Pt with other transition metals provides an effective strategy to modulate its catalytic HOR performance,but at the cost of mass activity due to the coverage of modifiers on Pt surface.Herein,we constructed dual junctions'Pt/nitrogen-doped carbon(Pt/NC)andδ-MoC/NC to modify electronic structure of Pt via interfacial electron transfer to acquire Pt-MoC@NC cat-alyst with electron-deficient Pt nanoparticles,simultaneously endowing it with high mass activity and durability of alkaline HOR.Moreover,the unique structure of Pt-MoC@NC endows Pt with a high CO-tolerance at 1,000 ppm CO/H2,a quality that commercial Pt-C catalyst lacks.The theoretical calculations not only confirm the diffusion of electrons from Pt/NC to MoC/NC could occur,but also demonstrate the negative shift of Pt d-band center for the optimized binding energies of*H,*OH and CO.
查看更多>>摘要：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 bound-aries between Ag shell and the Cu2O mediate local*CO coverage and promote*CHO intermediate forma-tion,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 electro-catalytic CO2 reduction.
查看更多>>摘要：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 attrib-uted 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 elec-trolyte 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 com-ponents 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 LiNi0.8Co0.1Mn0.1O2 and LiCoO2 cathodes(both load-ings～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.
查看更多>>摘要：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 concentra-tion at electrocatalyst interface for enhancing the CO2 mass transfer process,but also activate CO2 mole-cule 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 hydro-gen 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.
查看更多>>摘要：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 ℃,which are attributed to the notable stabilization of transition states by the enhanced acid acces-sibility and properly sized constraints of zeolite cavities owing to the good structural integrity.
查看更多>>摘要：Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collec-tive 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 com-monly 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 devel-oping perovskite NCs.
Anki Reddy MuleBhimanaboina RamuluShaik Junied ArbazAnand Kurakula...
579-591页
查看更多>>摘要：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 integ-rity of metal and redox materials on metallic frames may significantly boost charge storage and rate per-formance 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 var-ious portable electronic devices.
查看更多>>摘要：The development of a durable metallic coating on diverse substrates is both intriguing and challenging,particularly in the research of metal-conductive materials for applications such as batteries,soft electron-ics,and beyond.Herein,by learning from the pencil-writing process,a facile solid-ink rubbing technology(SIR-tech)is invented to address the above challenge.The solid-ink is exampled by rational combination of liquid metal and graphite particles.By harnessing the synergistic effects between rubbing and adhe-sion,controllable metallic skin is successfully formed onto metals,woods,ceramics,and plastics without limitation in size and shape.Moreover,outperforming pure liquid-metal coating,the composite metallic skin by SIR-tech is very robust due to the self-lamination of graphite nanoplate exfoliated by liquid-metal rubbing.The critical factors controlling the structures-properties of the composite metallic skin have been systematically investigated as well.For applications,the SIR-tech is demonstrated to fabricate high-performance composite current collectors for next-generation batteries without traditional metal foils.Meanwhile,advanced skin-electrodes are further demonstrated for stable triboelectricity genera-tion even under temperature fluctuation from-196 to 120 ℃.This facile and highly-flexible SIR-tech may work as a powerful platform for the studies on functional coatings by liquid metals and beyond.
查看更多>>摘要：P2-Na0.67Ni0.33Mn0.67O2(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 transforma-tion,Na+/vacancy ordering,and transition metal(TM)dissolution seriously damage its cycling stability and restrict its commercialization process.Herein,Na occupation manipulation and interface stabiliza-tion are proposed to strengthen the phase structure of NNMO by synergistic Zn/Ti co-doping and intro-ducing lithium difluorophosp(LiPO2F2)film-forming electrolyte additive.The Zn/Ti co-doping regulates the occupancy ratio of Nae/Naf at Na sites and disorganizes the Na+/vacancy ordering,resulting in a faster Na+diffusion kinetics and reversible P2-Z phase transition for P2-Na0.67Ni0.28Zn0.05Mn0.62Ti0.05O2(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 mech-anism of NNZMTO with LiPO2F2 additive.As a result,the NNZMTO displays outstanding capacity reten-tion 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.
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