查看更多>>摘要：Anode-free solid-state lithium metal batteries(AF-SSLBs)have the potential to deliver higher energy den-sity and improved safety beyond lithium-metal batteries.However,the unclear mechanism for the fast capacity decay in AF-SSLBs,either determined by dead Li or solid electrolyte interface(SEI),limits the proposal of effective strategies to prolong cycling life.To clarify the underlying mechanism,herein,the evolution of SEI and dead Li is quantitatively analyzed by a solid-state nuclear magnetic resonance(ss-NMR)technology in a typical LiPF6-based polymer electrolyte.The results show that the initial capacity loss is attributed to the formation of SEI,while the dead Li dominates the following capacity loss and the growth rate is 0.141 mA h cm-2 cycle-1.To reduce the active Li loss,the combination of inorganic-rich SEI and self-healing electrostatic shield effect is proposed to improve the reversibility of Li deposition/disso-lution behavior,which reduces the capacity loss rate for the initial SEI and following dead Li generation by 2.3 and 20.1 folds,respectively.As a result,the initial Coulombic efficiency(ICE)and stable CE increase by 15.1％and 15.3％in Li-Cu cells,which guides the rational design of high-performance AF-SSLBs.
查看更多>>摘要：This study investigates the dry reformation of methane(DRM)over Ni/Al2O3 catalysts in a dielectric barrier discharge(DBD)non-thermal plasma reactor.A novel hybrid machine learning(ML)model is developed to optimize the plasma-catalytic DRM reaction with limited experimental data.To address the non-linear and complex nature of the plasma-catalytic DRM process,the hybrid ML model integrates three well-established algorithms:regression trees,support vector regression,and artificial neural networks.A genetic algorithm(GA)is then used to optimize the hyperparameters of each algorithm within the hybrid ML model.The ML model achieved excellent agreement with the experimental data,demonstrating its efficacy in accurately predicting and optimizing the DRM process.The model was sub-sequently used to investigate the impact of various operating parameters on the plasma-catalytic DRM performance.We found that the optimal discharge power(20 W),CO2/CH4 molar ratio(1.5),and Ni load-ing(7.8 wt％)resulted in the maximum energy yield at a total flow rate of～51 mL/min.Furthermore,we investigated the relative significance of each operating parameter on the performance of the plasma-catalytic DRM process.The results show that the total flow rate had the greatest influence on the conversion,with a significance exceeding 35％for each output,while the Ni loading had the least impact on the overall reaction performance.This hybrid model demonstrates a remarkable ability to extract valuable insights from limited datasets,enabling the development and optimization of more efficient and selective plasma-catalytic chemical processes.
查看更多>>摘要：Piezoelectric materials have advantages of fine-tuning photocatalytic performance through harvesting mechanical energy and open a new avenue in facilitating green catalytic reaction.Herein,polyvinylidene fluoride(PVDF),a flexible piezoelectric material,was introduced to synthesize a novel Cd0.9Zn0.1S-ZnO@C/PVDF(CZS-ZO@C/PVDF)piezo-photocatalytic film by spin coating and immersion phase conver-sion method.Benefiting from the piezoelectricity of PVDF and the internal electric field(IEF)of CZS-ZO@C Step-scheme(S-Scheme)heterojunction,CZS-ZO@C/PVDF was able to induce a hydrogen generation rate of 34.9 mmol g-1 h-1 activated by ultrasound and visible light(U-L),which is～17.5 times of Cd0.9Zn0.1S/PVDF(CZS/PVDF)and～7.4 times of the photocatalysis rate activated by visible light only(L).Piezoelectric measurements and COMSOL simulation illustrated the excellent piezoelectricity of CZS-ZO@C/PVDF film,which exhibits a piezoelectric coefficient(d33)of 9.9 pm V-1 and a piezoelectric poten-tial of 874 mV(under 0.5 MPa).The reaction mechanism for the exceptional piezo-photocatalytic perfor-mance was finally disclosed through density functional theory(DFT)calculation and electrochemical tests.This study enriches the application scope of piezoelectric materials in sustainable energy catalysis and provides a new direction to develop efficient piezoelectric photocatalysts.
查看更多>>摘要：Printable mesoscopic perovskite solar cells(PM-PSCs)possess notable merits in terms of cost-effectiveness,easy manufacturing,and large scale applications.Nevertheless,the absence of a hole trans-port layer contributes to the exacerbation of carrier recombination,and the defects between the per-ovskite and electron transport layer(ETL)interfaces significantly decrease the efficiency of the devices.In this study,a bifunctional surface passivation approach is proposed by applying a thioacetamide(TAA)surfactant on the mesoporous TiO2 interface.The results demonstrate that TAA molecules could interact with TiO2,thereby diminishing the oxygen vacancy defects.Additionally,the amino group and sulfur atoms in TAA molecules act as Lewis base to effectively passivate the uncoordinated Pb2+in per-ovskite and improve the morphology of perovskite,and decrease the trap-state density of perovskite.The TAA passivation mechanism improves the alignment of energy levels between TiO2 and perovskite,facilitating electron transport and reducing carrier recombination.Consequently,the TAA-passivated device achieved a champion power conversion efficiency(PCE)of 17.86％with a high fill factor(FF)of 79.16％and an open-circuit voltage(VOC)of 0.971 V.This investigation presents a feasible strategy for interfacial passivation of the ETL to further improve the efficiency of PM-PSCs.
查看更多>>摘要：With the increasing spotlight in electric vehicles,there is a growing demand for high-energy-density bat-teries to enhance driving range.Consequently,several studies have been conducted on high-energy-density LiNixCoyMnzO2 cathodes.However,there is a limit to permanent performance deterioration because of side reactions caused by moisture in the atmosphere and continuous microcracks during cycling as the Ni content to express high energy increases and the content of Mn and Co that maintain structural and electrochemical stabilization decreases.The direct modification of the surface and bulk regions aims to enhance the capacity and long-term performance of high-Ni cathode materials.Therefore,an efficient modification requires a study based on a thorough understanding of the degrada-tion mechanisms in the surface and bulk region.In this review,a comprehensive analysis of various mod-ifications,including doping,coating,concentration gradient,and single crystals,is conducted to solve degradation issues along with an analysis of the overall degradation mechanism occurring in high-Ni cathode materials.It also summarizes recent research developments related to the following modifica-tions,aims to provide notable points and directions for post-studies,and provides valuable references for the commercialization of stable high-energy-density cathode materials.
Hari Narayanan VasavanManish BadoleSamriddhi SaxenaVelaga Srihari...
206-216页
查看更多>>摘要：Biphasic layered oxide cathodes,known for their superior electrochemical performance,are prime can-didates for commercializing in Na-ion batteries.Herein,we unveil a series of P3/P2 monophasic and biphasic Al-substituted Na3/4Mn5-x/8Al2x/8Ni3-x/8O2 layered oxide cathodes that lie along the'zero Mn3+line'in the Na3/4(Mn-AI-Ni)O2 pseudo-ternary system.The structural analysis showed a larger Na+conduction bottleneck area in both P3 and P2 structures with a higher Al3+content,which enhanced their rate per-formance.In each composition,the P3/P2 biphasic compound with nearly equal fractions of P3 and P2 phases outperformed their monophasic counterparts in almost all electrochemical performance param-eters.Operando synchrotron XRD measurements obtained for the monophasic P3 and biphasic P2/P3 samples revealed the absence of the O3 phase during cycling.The high structure stability and faster Na+transport kinetics in the biphasic samples underpins the enhancement of electrochemical properties in the Al-substituted P3/P2 cathodes.These results highlight fixed oxidation state lines as a novel tool to identify and design layered oxide cathodes for Na-ion batteries in pseudo-ternary diagrams involving Jahn-Teller active cations.
查看更多>>摘要：Developing advanced battery-type materials with abundant active sites,high conductivity,versatile mor-phologies,and hierarchically porous structures is crucial for realizing high-quality hybrid supercapaci-tors.Herein,heterogeneous FeS@NiS is synthesized by cationic Co doping via surface-structure engineering.The density functional theory(DFT)theoretical calculations are firstly performed to predict the advantages of Co dopant by improving the OH-adsorption properties and adjusting electronic struc-ture,benefiting ions/electron transfer.The dynamic surface evolution is further explored which demon-strates that CoFeS@CoNiS could be quickly reconstructed to Ni(Co)Fe2O4 during the charging process,while the unstable structure of the amorphous Ni(Co)Fe2O4 results in partial conversion to Ni/Co/FeOOH at high potentials,which contributes to the more reactive active site and good structural stability.Thus,the free-standing electrode reveals excellent electrochemical performance with a superior capacity(335.6 mA h g-1,2684 F g-1)at 3 A g-1.Furthermore,the as-fabricated device shows a quality energy density of 78.1 W h kg-1 at a power density of 750 W kg-1 and excellent cycle life of 92.1％capacitance retention after 5000 cycles.This work offers a facile strategy to construct versatile morphological struc-tures using electrochemical activation and holds promising applications in energy-related fields.
查看更多>>摘要：Lithium metal is considered as the ultimate anode material for the next generation of high-energy density batteries.However,non-uniform lithium dendrite growth,serious electrolyte consumption,and signifi-cant volume changes during lithium deposition/stripping processes lead to sustained accumulation of inactive lithium and poor cycling reversibility.Quantifying the formation and evolution of inactive lithium under different conditions and fully evaluating the complex failure modes are the key issues in this challenging field.This article comprehensively reviews recent research progress on the quantification of formation and evolution of inactive lithium detected by different quantitative techniques in recharge-able lithium metal batteries.The key research challenges such as failure mechanism,modification strate-gies and operando characterization of lithium metal anodes are systematically summarized and prospected.This review provides a new angle of view to understand failure mechanism of lithium metal anodes and inspiration and guidance for the future development of rechargeable lithium metal batteries.
查看更多>>摘要：The NiOx/perovskite interface in NiOx-based inverted perovskite solar cells(PSCs)is one of the main issues that restrict device performance and long-term stability,as the unwanted interfacial defects and undesirable redox reactions cause severe interfacial non-radiative recombination and open-circuit volt-age(Voc)loss.Herein,a series of self-assembled molecules(SAMs)are employed to bind,bridge,and sta-bilize the NiOx/perovskite interface by regulating the electrostatic potential.Based on systematically theoretical and experimental studies,4-pyrazolecarboxylic acid(4-PCA)is proven as an efficient mole-cule to simultaneously passivate the NiOx and perovskite surface traps,release the interfacial tensile stress as well as quench the detrimental interface redox reactions,thus effectively suppressing the inter-facial non-radiative recombination and enhancing the quality of perovskite crystals.Consequently,the PSCs with 4-PCA treatment exhibited an eminently increased Voc,leading to a significant increase in power conversion efficiency from 21.28％to 23.77％.Furthermore,the unencapsulated devices maintain 92.6％and 81.3％of their initial PCEs after storing in air with a relative humidity of 20％-30％for 1000 h and heating at 65 ℃ for 500 h in a N2-filled glovebox,respectively.
查看更多>>摘要：Perovskite oxides has been attracted much attention as high-performance oxygen carriers for chemical looping reforming of methane,but they are easily inactivated by the presence of trace H2S.Here,we pro-pose to modulate both the activity and resistance to sulfur poisoning by dual substitution of Mo and Ni ions with the Fe-sites of LaFeO3 perovskite.It is found that partial substitution of Ni for Fe substantially improves the activity of LaFeO3 perovskite,while Ni particles prefer to grow and react with H2S during the long-term successive redox process,resulting in the deactivation of oxygen carriers.With the pres-ence of Mo in LaNi0.05Fe0.95O3-δ perovskite,H2S preferentially reacts with Mo to generate MoS2,and then the CO2 oxidation can regenerate Mo via removing sulfur.In addition,Mo can inhibit the accumulation and growth of Ni,which helps to improve the redox stability of oxygen carriers.The LaNi0.05Mo0.07Fe0.88O3-δ oxygen carrier exhibits stable and excellent performance,with the CH4 conver-sion higher than 90％during the 50 redox cycles in the presence of 50 ppm H2S at 800 ℃.This work high-lights a synergistic effect in the perovskite oxides induced by dual substitution of different cations for the development of high-performance oxygen carriers with excellent sulfur tolerance.
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