查看更多>>摘要：The aqueous zinc ion batteries(AZIBs)are thought as promising competitors for electrochemical energy storage,though their wide application is curbed by the uncontrollable dendrite growth and gas evolution side reactions.Herein,to stabilize both zinc anodes and water molecules,we developed a modified elec-trolyte by adding a trace amount of N,N-diethylformanmide(DEF)into the ZnSO4 electrolyte for the first time in zinc ion batteries.The effectiveness of DEF is predicted by the comparison of donor number and its preferential adsorption behavior on the zinc anode is further demonstrated by several spectroscopy characterizations,electrochemical methods,and molecular dynamics simulation.The modified elec-trolyte with 5％v.t.DEF content can ensure a stable cycling life longer than 3400 h of Zn||Zn symmetric cells and an ultra-reversible Zn stripping/plating process with a high coulombic efficiency of 99.7％.The Zn||VO2 full cell maintains a capacity retention of 83.5％and a 104 mA h g-1 mass capacity after 1000 cycles.This work provides insights into the role of interfacial adsorption behavior and the donor number of additive molecules in designing low-content and effective aqueous electrolytes.
查看更多>>摘要：Bismuth-based catalysts are highly promising for the electrochemical carbon dioxide reduction reaction(eCO2RR)to formate product.However,achieving high activity and selectivity towards formate and ensuring long-term stability remains challenging.This work reports the oxygen plasma inducing strategy to construct the abundant grain boundaries of Bi/BiOx on ultrathin two-dimensional Bi nanosheets.The oxygen plasma-treated Bi nanosheet(OP-Bi)exhibits over 90％Faradaic efficiency(FE)for formate at a wide potential range from-0.5 to-1.1 V,and maintains a great stability catalytic performance without significant decay over 30 h in flow cell.Moreover,membrane electrode assembly(MEA)device with OP-Bi as catalyst sustains the robust current density of 100 mA cm-2 over 50 h,maintaining a formate FE above 90％.In addition,rechargeable Zn-CO2 battery presents the peak power density of 1.22 mW cm-2 with OP-Bi as bifunctional catalyst.The mechanism experiments demonstrate that the high-density grain boundaries of OP-Bi provide more exposed active sites,faster electron transfer capac-ity,and the stronger intrinsic activity of Bi atoms.In situ spectroscopy and theoretical calculations further elucidate that the unsaturated Bi coordination atoms between the grain boundaries can effectively acti-vate CO2 molecules through elongating the C-O bond,and reducing the formation energy barrier of the key intermediate(*OCOH),thereby enhancing the catalytic performance of eCO2RR to formate product.
查看更多>>摘要：Lithium(Li)metal is regarded as a promising anode candidate for high-energy-density rechargeable bat-teries.Nevertheless,Li metal is highly reactive against electrolytes,leading to rapid decay of active Li metal reservoir.Here,alloying Li metal with low-content magnesium(Mg)is proposed to mitigate the reaction kinetics between Li metal anodes and electrolytes.Mg atoms enter the lattice of Li atoms,form-ing solid solution due to the low amount(5 wt％)of Mg.Mg atoms mainly concentrate near the surface of Mg-alloyed Li metal anodes.The reactivity of Mg-alloyed Li metal is mitigated kinetically,which results from the electron transfer from Li to Mg atoms due to the electronegativity difference.Based on quanti-tative experimental analysis,the consumption rate of active Li and electrolytes is decreased by using Mg-alloyed Li metal anodes,which increases the cycle life of Li metal batteries under demanding conditions.Further,a pouch cell(1.25 Ah)with Mg-alloyed Li metal anodes delivers an energy density of 340 Wh kg-1 and a cycle life of 100 cycles.This work inspires the strategy of modifying Li metal anodes to kinet-ically mitigate the side reactions with electrolytes.
查看更多>>摘要：Cobalt-free,nickel-rich LiNi1-xAlxO2(x ≤ 0.1)is an attractive cathode material because of high energy den-sity and low cost but suffers from severe structural degradation and poor rate performance.In this study,we propose a molten salt-assisted synthesis in combination with a Li-refeeding induced aluminum seg-regation strategy to prepare Li5AlO4-coated single-crystalline slightly Li-rich Li1.04Ni0.92Al0.04O2.The sym-biotic formation of Li5AlO4 from reaction between molten lithium hydroxide and doped aluminum in the bulk ensures a high lattice matching between the Ni-rich oxide and the homogenous conductive Li5AlO4 that permits high Li+conductivity.Benefiting from mitigated undesirable side reactions and phase evo-lution,the Li5AlO4-coated single-crystalline Li1.04Ni0.92Al0.04O2 delivers a high specific capacity of 220.2 mA h g-1 at 0.1 C and considerable rate capability(182.5 mA h g-1 at 10 C).Besides,superior capac-ity retention of 90.8％is obtained at 1/3 C after 100 cycles in a 498.1 mA h pouch full cell.Furthermore,the particulate morphology of Li1.04Ni0.92Al0.04O2 remains intact after cycling at a cutoff voltage of 4.3 V,whereas slightly Li-deficient Li0.98Ni0.97Al0.05O2 features intragranular cracks and irreversible lattice dis-tortion.The results highlight the value of molten salt-assisted synthesis and Li-refeeding induced ele-mental segregation strategy to upgrade Ni-based layered oxide cathode materials for advanced Li-ion batteries.
查看更多>>摘要：Metal halide perovskites(MHP)are potential candidates for the photocatalytic reduction of CO2 due to their long photogenerated carrier lifetime and charge diffusion length.However,the conventional long-chain ligand impedes the adsorption and activation of CO2 molecules in practical applications.Here,a ligand modulation technology is employed to enhance the photocatalytic CO2 reduction activity of lead-free Cs2AgInCl6 microcrystals(MCs).The Cs2AgInCl6 MCs passivated by Oleic acid(OLA)and Octanoic acid(OCA)are used for photocatalytic CO2 reduction.The results show that the surface defects and electronic properties of Cs2AglnCl6 MCs can be adjusted through ligand modulation.Compared with the OLA-Cs2AgInCl6,the OCA-Cs2AgInCl6 catalyst demonstrated a significant improvement in the catalytic yield of CO and CH4.The CO and CH4 catalytic yields of OCA-Cs2AgInCl6 reached 171.88 and 34.15 μmol g-1 h-1 which were 2.03 and 12.98 times higher than those of OLA-Cs2AgInCl6,and the total electron consumption rate of OCA-Cs2AgInCl6 was 615.2 μmol g-1 h-1 which was 3.25 times higher than that of OLA-Cs2AgInCl6.Furthermore,in situ diffuse reflectance infrared Fourier transform spectra revealed the enhancement of photocatalytic activity in Cs2AgInCl6 MCs induced by ligand modulation.This study illustrates the potential of lead-free Cs2AgInCl6 MCs for efficient photocatalytic CO2 reduction and provides a ligand modulation strategy for the active promotion of MHP photocatalysts.
查看更多>>摘要：2,5-Furandicarboxylic acid(FDCA)is a promising biomass-derived polymeric monomer that serves as an attractive alternative to terephthalic acid derived from fossil resources.However,the green and efficient production of FDCA through the oxidation of 5-hydroxymethylfurfural(HMF)and its derivatives is still rudimentary under base-free conditions.In this work,oxygen-vacancy-rich MnOx was prepared and dis-played a strong adsorption and anchoring ability to Ru species that mainly exposed the(210)plane of RuO2,bringing about highly dispersed and active interfacial Ru-O-Mn structures.Experimental results and density functional theory calculations confirm that these above features greatly facilitate the adsorp-tion/activation of oxygen and the dehydrogenation-oxidation of HMF/5-methoxymethylfurfural(MMF),which enables an efficient FDCA production under base-free and mild conditions.Notably,a desirable FDCA yield of 86.56％was still obtained from concentrated HMF(10 wt％)under base-free conditions over oxygen-vacancy-rich MnOx supported RuOx(1.0 MPa O2,120 ℃,6 h).This work delineates a facile cata-lyst preparation strategy for HMF/MMF oxidation,and might open a new avenue for the green synthesis of FDCA under base-free conditions.
查看更多>>摘要：Constructing robust surface and bulk structure is the prerequisite for realizing high performance high voltage LiCoO2(LCO).Herein,we manage to synthesize a surface Mg-doping and bulk Al-doping core-shell structured LCO,which demonstrates excellent cycling performance.Half-cell shows 94.2％capacity retention after 100 cycles at 3.0-4.6 V(vs.Li/Li+)cycling,and no capacity decay after 300 cycles for full-cell test(3.0-4.55 V).Based on comprehensive microanalysis and theoretical calculations,the degrada-tion mechanisms and doping effects are systematically revealed.For the undoped LCO,high voltage cycling induces severe interfacial and bulk degradations,where cracks,stripe defects,fatigue H2 phase,and spinel phase are identified in grain bulk.For the doped LCO,Mg-doped surface shell can suppress the interfacial degradations,which not only stabilizes the surface structure by forming a thin rock-salt layer but also significantly improves the electronic conductivity,thus enabling superior rate performance.Bulk Al-doping can suppress the lattice"breathing"effect and the detrimental H3 to H1-3 phase transition,which minimizes the internal strain and defects growth,maintaining the layered structure after pro-longed cycling.Combining theoretical calculations,this work deepens our understanding of the doping effects of Mg and Al,which is valuable in guiding the future material design of high voltage LCO.
查看更多>>摘要：Solar-driven interfacial water evaporation(SIWE)offers a superb way to leverage concentrated solar heat to minimize energy dissipation during seawater desalination.It also engenders overlapped temperature-salinity gradient(TSG)between water-air interface and adjacent seawater,affording opportunities of har-nessing electricity.However,the efficiency of conventional SIWE technologies is limited by significant challenges,including salt passivation to hinder evaporation and difficulties in exploiting overlapped TSG simultaneously.Herein,we report self-sustaining hybrid SIWE for not only sustainable seawater desalination but also efficient electricity generation from TSG.It enables spontaneous circulation of salt flux upon seawater evaporation,inducing a self-cleaning evaporative interface without salt passivation for stable steam generation.Meanwhile,this design enables spatial separation and simultaneous utiliza-tion of overlapped TSG to enhance electricity generation.These benefits render a remarkable efficiency of 90.8％in solar energy utilization,manifesting in co-generation of solar steam at a fast rate of 2.01 kg m-2-h-1 and electricity power of 1.91 W m-2 with high voltage.Directly interfacing the hybrid SIWE with sea-water electrolyzer constructs a system for water-electricity-hydrogen co-generation without external electricity supply.It produces hydrogen at a rapid rate of 1.29 L h-1 m-2 and freshwater with 22 times lower Na+concentration than the World Health Organization(WHO)threshold.
查看更多>>摘要：Lithium-sulfur batteries(LSBs)are considered promising candidates for next-generation battery tech-nologies owing to their outstanding theoretical energy density and cost-effectiveness.However,the low conductivity and polysulfide shuttling effect of S cathodes severely hamper the practical perfor-mance of LSBs.Herein,in situ-generated single layer MXene nanosheet/hierarchical porous carbonized wood fiber(MX/PCWF)composites are prepared via a nonhazardous eutectic activation strategy coupled with pyrolysis-induced gas diffusion.The unique architecture,wherein single layer MXene nanosheets are constructed on carbonized wood fiber walls,ensures rapid polysulfide conversion and continuous electron transfer for redox reactions.The C-Ti-C bonds formed between MXene and PCWF can consider-ably expedite the conversion of polysulfides,effectively suppressing the shuttle effect.An impressive capacity of 1301.1 mA h g-1 at 0.5 C accompanied by remarkable stability is attained with the MX/PCWF host,as evidenced by the capacity maintenance of 722.6 mA h g-1 after 500 cycles.Notably,the MX/PCWF/S cathode can still deliver a high capacity of 886.8 mA h g-1 at a high S loading of 5.6 mg cm-2.The construction of two-dimensional MXenes on natural wood fiber walls offers a competitive edge over S-based cathode materials and demonstrates a novel strategy for developing high-performance batteries.
查看更多>>摘要：Developing an energy supply-chain based on renewable biomass holds great potential to build a low car-bon society.High-energy-density(HED)jet fuel,featuring unique fused/strained cycloalkanes,is of great significance for volume-limited military aircrafts,as their high density and combustion heat can extend flight duration and increase the payload.Therefore,the exploration of biomass-based routes towards HED fuel has drawn much attention over the past decade.Cycloaddition reaction features rapid construction of various carbocycles in an atom-and step-economical fashion.This elegant strategy has been widely applied in the manufacture of sustainable HED fuel.Here we carefully summarize the progress achieved in this fascinating area and the review is categorized by the cycloaddition patterns including[4+2],[2+2],[4+4],and[2+1]cycloadditions.Besides,the energy densities of the as-prepared biofuels and petroleum-based fuels(conventional Jet-A and advanced JP-10)are also compared.This review will provide impor-tant insights into rational design of new HED fuel with different ring-types/sizes and inspire the chemists to turn those literature studies into practical applications in military field.
NETL
NSTL
万方数据