Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of va...Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.展开更多
Pb-Sn mixed perovskite solar cells(PSCs)are crucial components for realizing efficient all-perovskite tandem devices.However,their efficiency and stability are severely limited by oxidative degradation(Sn^(4+)formatio...Pb-Sn mixed perovskite solar cells(PSCs)are crucial components for realizing efficient all-perovskite tandem devices.However,their efficiency and stability are severely limited by oxidative degradation(Sn^(4+)formation)and metallic defects(Sn^(0)/Pb^(0)).In addition,the rapid and uncontrolled Sn^(2+)nucleation kinetics result in nonuniform crystallization.Herein,we introduce a natural redox shuttle glutathione(GSH)in Pb-Sn mixed PSCs,achieving regenerable antioxidation and crystallization regulation simultaneously.The reversible redox reactions between GSH and glutathione disulfide(GSSG)enable the self-healing of Sn^(4+)and Sn^(0)/Pb^(0)impurities,creating a regenerable antioxidation protective shell at the perovskite interfaces.Meanwhile,the strong coordination between GSH and perovskite regulates the crystallization process,optimizing the nucleation and crystallization kinetics.Furthermore,the GSH incorporation creates a high-quality charge separation junction at the perovskite/hole transport layer,facilitating carrier separation and extraction.The optimized Pb-Sn PSCs exhibit impressive power conversion efficiencies(PCEs)of up to 23.71%.The champion all-perovskite tandem PSCs with GSH achieve a PCE of 28.49%and retain 90%of the initial PCE after 560 h of continuous illumination.This work establishes a new nature-inspired redox shuttling strategy and elucidates its working mechanism,advancing the development of efficient and stable all-perovskite tandem solar cells.展开更多
Photo-assisted lithium–sulfur batteries(PALSBs)offer an eco-friendly solution to address the issue of sluggish reaction kinetics of conventional LSBs.However,designing an efficient photoelectrode for practical implem...Photo-assisted lithium–sulfur batteries(PALSBs)offer an eco-friendly solution to address the issue of sluggish reaction kinetics of conventional LSBs.However,designing an efficient photoelectrode for practical implementation remains a significant challenge.Herein,we construct a free-standing polymer–inorganic hybrid photoelectrode with a direct Z-scheme heterostructure to develop high-efficiency PALSBs.Specifically,polypyrrole(PPy)is in situ vapor-phase polymerized on the surface of N-doped TiO_(2) nanorods supported on carbon cloth(N-TiO_(2)/CC),thereby forming a well-defined p–n heterojunction.This architecture efficiently facilitates the carrier separation of photo-generated electron–hole pairs and significantly enhances carrier transport by creating a built-in electric field.Thus,the PPy@N-TiO_(2)/CC can simultaneously act as a photocatalyst and an electrocatalyst to accelerate the reduction and evolution of sulfur,enabling ultrafast sulfur redox dynamics,as convincingly validated by both theoretical simulations and experimental results.Consequently,the PPy@N-TiO_(2)/CC PALSB achieves a high discharge capacity of 1653 mAh g^(−1),reaching 98.7%of the theoretical value.Furthermore,5 h of photo-charging without external voltage enables the PALSB to deliver a discharge capacity of 333 mAh g^(−1),achieving dual-mode energy harvesting capabilities.This work successfully integrates solar energy conversion and storage within a rechargeable battery system,providing a promising strategy for sustainable energy storage technologies.展开更多
Metal halide perovskites(MHPs)with striking electrical and optical properties have appeared at the forefront of semiconductor materials for photocatalytic redox reactions but still suffer from some intrinsic drawbacks...Metal halide perovskites(MHPs)with striking electrical and optical properties have appeared at the forefront of semiconductor materials for photocatalytic redox reactions but still suffer from some intrinsic drawbacks such as inferior stability,severe charge-carrier recombination,and limited active sites.Heterojunctions have recently been widely constructed to improve light absorption,passivate surface for enhanced stability,and promote charge-carrier dynamics of MHPs.However,little attention has been paid to the review of MHPs-based heterojunctions for photocatalytic redox reactions.Here,recent advances of MHPs-based heterojunctions for photocatalytic redox reactions are highlighted.The structure,synthesis,and photophysical properties of MHPs-based heterojunctions are first introduced,including basic principles,categories(such as Schottky junction,type-I,type-II,Z-scheme,and S-scheme junction),and synthesis strategies.MHPs-based heterojunctions for photocatalytic redox reactions are then reviewed in four categories:H2evolution,CO_(2)reduction,pollutant degradation,and organic synthesis.The challenges and prospects in solar-light-driven redox reactions with MHPs-based heterojunctions in the future are finally discussed.展开更多
High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs ...High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs generally enforcing stoichiometric symmetry(Ni=Mn)yield low Fe redox activity.Herein,we propose a valence engineering strategy that breaks conventional Ni/Mn stoichiometry to reconfigure Fe's local chemical environment and unlock unprecedented redox depth.Density functional theory(DFT)calculations reveal that the designed NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode exhibits a reduced Bader charge on Fe(1.598 vs.1.638 in NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2))and elevated Fe 3d orbital energy,signifying enhanced Fe redox activity.This configuration enables an exceptional Fe^(2.60+)/Fe^(3.88+)redox(1.28 e~-per Fe),delivering a reversible capacity of184.3 mAh g^(-1)within 2-4.2 V at 0.2 C,markedly exceeding the benchmark NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(161.3 mAh g^(-1))with low reaction depth of Fe^(3.01+)/Fe^(3.61+).The intensified cationic redox reaction enables an ultrahigh energy density of 596 Whkg-1.The NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode demonstrates robust performance over a broad temperature range from-15℃to 60℃.In situ and ex situ characterizations unveil a reversible O3■P3■OP2 phase transition with minimal volume change(1.88%)that circumvents detrimental deleterious O'3 intermediates and intragranular cracking.This work establishes valence engineering as a paradigm to consolidate cationic redox reaction in high-energy layered sodium oxide cathodes.展开更多
Lithium-sulfur(Li-S)batteries hold great promise for high-energy–density energy storage applications but are plagued by the severe shuttle effect and sluggish conversion kinetics of lithium polysulfides(Li PSs).We he...Lithium-sulfur(Li-S)batteries hold great promise for high-energy–density energy storage applications but are plagued by the severe shuttle effect and sluggish conversion kinetics of lithium polysulfides(Li PSs).We herein report a d-p-f orbital coupling strategy to tackle these critical challenges by incorporating Eu 4f orbitals to activate both metallic(Ni)and non-metallic(Se)sites of Ni Se.The imported Eu atoms could induce essential Ni 3d and Se 4p orbital reconstruction through gradient d-p-f coupling,thereby optimizing the band center alignment between Ni Se and Li PSs.Such electronic reconstruction strengthens both d-p hybridization between Ni and Li PSs and s-p hybridization between Se and Li PSs,which can not only enhance the chemisorption affinity toward Li PSs but also accelerate interfacial charge transfer kinetics,leading to suppressed shuttle effect and boosted Li PSs conversion kinetics.Therefore,the Li-S batteries assembled with Eu incorporated Ni Se deliver exceptional electrochemical performance with a high specific capacity of 896.2 m Ah g^(-1)at 4 C and a retained areal capacity of 5.66 m Ah cm^(-2)under a high sulfur loading of 5.94 mg cm^(-2)after 100 cycles.This work underscores the critical role of rare-earth 4f orbital coupling for modulating the active sites to construct high-efficiency electrocatalysts for Li-S batteries and beyond.展开更多
Lithium-rich manganese-based cathode materials,as promising candidates for next-generation highenergy–density lithium-ion batteries due to their high specific capacity(>250 mAh g^(-1))and costeffectiveness,are lim...Lithium-rich manganese-based cathode materials,as promising candidates for next-generation highenergy–density lithium-ion batteries due to their high specific capacity(>250 mAh g^(-1))and costeffectiveness,are limited by severe capacity decay and voltage fade driven by irreversible structural transitions and oxygen release during cycling.Here,we report a Ti/Si dual-element modification strategy for cobalt-free Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(LNMO)cathodes.The Ti/Si co-modified TS-LNMO cathode demonstrates superior structural stability and electrochemical performance.Bulk Ti^(4+)doping stabilizes the oxygen framework via robust Ti–O bonds and enhances the lattice oxygen redox reversibility,while an in situ formed Li_(2) SiO_(3) layer suppresses interfacial side reactions,enhances lithium-ion diffusion,and prevents HF-induced erosion.As a result,the TS-LNMO cathode achieves 90%capacity retention after 200 cycles at 0.5 C and maintains -80%capacity in full cells cycled to 4.8 V.Additionally,the TS-LNMO cathode exhibits impressive rate performance even at a high rate of 5 C.This work offers an effective strategy for advancing cobalt-free,high-performance lithium-rich cathodes for sustainable energy applications.展开更多
The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stab...The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stability compared to conventional doping modifications,rational element selection for optimizing OR reversibility remains unexplored.Here,we propose an entropy engineering design paradigm for “oxygen-anchoring”,where optimal cation electronegativity(>Mn,1.55)and d(3d/4d)-p orbital hybridization synergistically enhance transition metal–oxygen(TM–O)covalency and stabilize the O2p state.Two high-entropy Li-rich layered oxides:Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Al_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTANM)and Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTCNM)were synthesized using partial nano-scale precursors and comparatively evaluated.MTCNM exhibits enhanced electrochemical performance and superior oxygen stability compared to MTANM by replacing Al with higher-electronegativity Cu,which possesses improved orbital overlap with oxygen.Both experiments and density functional theory(DFT)calculations demonstrate that element selection changes the covalency of TM–O through altered electronegativity and d orbitals-p orbitals(d-p)hybridization.Further stepwise screening selected the optimal elemental combination Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Cr_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)Ru_(0.02)O_(2)(CCNMR),which achieved near 100%capacity retention after 150 cycles at 1 C,50℃,with its voltage decay effectively suppressed.This work establishes a rational element-screening paradigm for entropy-stabilized OR chemistry in high-energy cathodes.展开更多
Redox-active covalent organic polymers(COPs)have emerged as appealing renewable electrode materials for next-generation Li-ion batteries,but their performance is limited by insufficient redox sites and inadequate Li-i...Redox-active covalent organic polymers(COPs)have emerged as appealing renewable electrode materials for next-generation Li-ion batteries,but their performance is limited by insufficient redox sites and inadequate Li-ion diffusion.Here,we develop a novel class of mesoporous covalent organic polymer(namely TF-Azo-COP)bearing multiple redox sites and explore its first use as efficient 18-electron-redox anodes for superior Li-ion storage in both coin-type and fiber-type batteries.The newly produced TF-Azo-COP involves three types of active sites including C=N in triazines and imines,N=N in azo,and C6-ring aromatics to enable 18-Li-ion storage on one repeatable segment,while affording extendedπ-conjugation for fast electron transfer and a pore size of~2.5 nm for facilitated ion diffusion with a high coefficient up to~10^(-10)cm^(2)s^(-1)—superior to some reported organic electrodes.Meriting from the above,pairing TF-Azo-COP with metal Li endows a coin cell with good cycling stability and a large reversible capacity of 795.4 mAh g^(-1)at 0.1 A g^(-1)—representing one of the best performances among reported organic electrodes.When coupled with fiber-shaped LiFePO_(4)cathodes,the assembled fiber cell delivers an excellent combination of linear capacity(0.23 mAh cm^(-1)),energy density(0.55 mWh cm^(-1)),cycling stability(250 cycles),and good flexibility.展开更多
Sluggish kinetics coupled with parasitic shuttling reactions are pivotal challenges hindering the performance of lithium-sulfur(Li-S)batteries.Improving areal capacity and cyclability of Li-S batteries can be achieved...Sluggish kinetics coupled with parasitic shuttling reactions are pivotal challenges hindering the performance of lithium-sulfur(Li-S)batteries.Improving areal capacity and cyclability of Li-S batteries can be achieved by addressing these challenges.A composite sulfur host material is synthesized herein by in situ anchoring ultrafine cobalt-iron phosphide nanoparticles(5-7 nm)onto a hollow mesoporous carbon sphere(HMCS)framework.This strategy achieved exceptional spatial restriction and a high density of catalytically active sites through the encapsulation of sulfur within a hollow-structured framework.Specifically,HMCS expedites rapid Li_(2)S nucleation kinetics,while CoFeP facilitates robust Li_(2)S dissolution kinetics by mitigating decomposition barriers.This synergistic integration equips CoFeP@HMCS with robust bi-directional catalytic activity,significantly promoting interracial charge-transfer,facilitate sulfu r multistep catalytic conversion,and inhibiting shuttling.Consequently,the battery exhibits excellent rate performance(991 mA h g^(-1) at 5.0 C)and retains a high areal capacity of 6.06 mA h cm^(-2) after 200 cycles under a high areal sulfur loading of 8.2 mg cm^(-2) but a low electrolyte/sulfur ratio of 4.8μL mg^(-1).This work contributes to enhancing the practical specific capacity of lithium-sulfur batteries and deepens the understanding of catalysts enabling bidirectional electrocatalytic sulfur conversion.展开更多
Redox mediators(RMs)represent the most promising strategy to address the sluggish kinetics of lithium-oxygen(Li-O_(2))batteries.To achieve high-energy and cost-effective Li-O_(2)batteries,carbon materials are typicall...Redox mediators(RMs)represent the most promising strategy to address the sluggish kinetics of lithium-oxygen(Li-O_(2))batteries.To achieve high-energy and cost-effective Li-O_(2)batteries,carbon materials are typically regarded as ideal cathodes in these systems.However,the impact of their surface properties—which often regulate specific discharge pathways—on the RM-mediated oxygen reduction reaction(ORR)remains unclear.In this study,CNTs electrodes with different surface properties are fabricated.Results suggest that CNTs with more surface defects not only promote the unmediated discharge pathway even in RMs-involved battery systems but also exacerbate the corrosion of carbon cathodes.This,in turn,leads to the undesired accumulation of Li_(2)O_(2)and Li_(2)CO_(3)on the cathode surface,which hinders effective and continuous electron transfer between the cathode and RMs,ultimately decreasing the catalytic activity of RMs.As a result,the discharge capacity of the battery is seriously diminished,especially at large current densities.These findings underscore the significance of surface engineering in advancing the performance of RMs-assisted Li-O_(2)batteries.展开更多
Vanadium redox flow battery(VRFB),as a potential technology for next-generation energy storage system,is restricted by the slow redox kinetics of vanadium ions.Implementing interface engineering strategies to function...Vanadium redox flow battery(VRFB),as a potential technology for next-generation energy storage system,is restricted by the slow redox kinetics of vanadium ions.Implementing interface engineering strategies to functionalize the surface of MXene can effectively address this challenge.Herein,a Nb_(2)CT_(x)/Nb_(2)O_(5)Schottky heterostructure is constructed to facilitate high-speed charge transfer at the VRFB electrode through controllable in-situ oxidation.The loading amount of Nb_(2)O_(5) nanorods on the surface of Nb_(2)CT_(x) nanosheets was regulated by varying the hydrothermal reaction time.Density functional theory calculations confirm that the Schottky barrier formed between Nb_(2)CT_(x) and Nb_(2)O_(5) leads to the establishment of an internal electric field and reconfigures the electronic structure of surficial active sites.The rich pore structure of Nb_(2)CT_(x)/Nb_(2)O_(5) electrode effectively shortens the diffusion path for vanadium ions,while its excellent hydrophilicity enhances the interaction between vanadium ions and the electrodes.Compared with graphite felt,Nb_(2)CT_(x)/Nb_(2)O_(5)-2@GF cell shows a 20%increase in energy efficiency(EE)at 150 mA cm^(-2) cycling,reaching 75%,while maintaining stable performance for over 800 cycles.This means a significant advancement in the development of high-performance electrodes for VRFBs.This work offers an efficient and scalable strategy for the design of redox flow batteries.展开更多
Photoredox catalysis has made significant advances in stateof-the-art chemical synthesis,drawing energy from inexhaustible light and enabling various organic transformations to occur under mild reaction conditions.Ove...Photoredox catalysis has made significant advances in stateof-the-art chemical synthesis,drawing energy from inexhaustible light and enabling various organic transformations to occur under mild reaction conditions.Over the past few years,a variety of homogeneous and heterogeneous photocatalysts have been applied in the photoredox catalysis.Heterogeneous photoredox catalysis offers advantages such as easy separation and superior recyclability compared to homogeneous counterparts,although homogenous catalysts are usually associated with higher activities and selectivity.From a practical perspective,an optimal photoredox catalytic system would integrate the advantages of both homogeneous and heterogeneous cases.展开更多
Research on changes in the redox conditions of bottom waters is essential for understanding deep water circulation,global ocean currents,climate change,and ecosystem health.Through sedimentary geological methods,a dee...Research on changes in the redox conditions of bottom waters is essential for understanding deep water circulation,global ocean currents,climate change,and ecosystem health.Through sedimentary geological methods,a deeper understanding of the complex relationships between various environmental changes can be achieved,providing detailed evidence and theoretical support for global climate change research.The Ross Sea in Antarctica plays a key role in the formation of Antarctic bottom water(AABW),and the complex climate changes since the last glacial maximum(LGM)make it particularly significant for study.This research analyzes core ANT32-RB16C from the Ross Sea using geochemical proxies such as major and trace elements,grain size,and redox-sensitive indicators like Mn/Ti,Co/Ti,Mo/Ti,Cd/Ti,U/Th,and Ni/Co molar concentration ratios.Combining this data with a previously established chronological framework,the study explores the evolution of redox conditions in the Ross Sea’s deep waters since the LGM.The results show that the deep waters have remained oxygen-rich since the LGM,with significant changes in four stages.Stage 1(24.7–15.7 cal ka BP):Strong oxidizing conditions,likely due to enhanced formation of Ross Sea bottom water(RSBW),increasing oxygen levels.Stage 2(15.7–4.5 cal ka BP):Weakened oxidizing conditions as temperatures rose and ice shelves retreated,increasing primary productivity and depleting oxygen.Stage 3(4.5–1.5 cal ka BP):Continued decline in oxidizing conditions,possibly linked to high primary productivity and oxygen consumption.Stage 4(1.5 cal ka BP to present):A rapid recovery of oxidizing conditions,likely driven by temperature drops,increased RSBW formation,and decreased productivity.展开更多
Redox flow batteries have gained wide attention at home and abroad as a long-duration energy storage technology with the advantages of high safety,long lifespan,mutual independence of capacity and power,and easy recyc...Redox flow batteries have gained wide attention at home and abroad as a long-duration energy storage technology with the advantages of high safety,long lifespan,mutual independence of capacity and power,and easy recycling.However,the current battery management technology faces significant challenges,and there is room for development.Digital twin(DT),as a technology that collectively senses,evaluates,predicts,and optimizes characteristics,is promising to contribute to redox flow batteries’operation,maintenance,and management.This paper begins with a brief description of redox flow batteries,followed by a short explanation of the concept and application of DTs.DTs have already made some progress in the field of batteries,and can be applied to solve the problems of redox flow batteries in terms of thermal management and system optimization.Finally,the paper analyzes the combination of redox flow battery and DT architecture,which is expected to contribute to developing DT technology for redox flow batteries.展开更多
The first example of Nd@C_(3)N_(4)-photoredox/chlorine dual catalyzed alkylation with unactivated alkanes as the alkyl sources has been developed,which allows for the synthesis of various 4-alkylated cyclic sulfonyl k...The first example of Nd@C_(3)N_(4)-photoredox/chlorine dual catalyzed alkylation with unactivated alkanes as the alkyl sources has been developed,which allows for the synthesis of various 4-alkylated cyclic sulfonyl ketimines.In this process,chlorine functions as both a redox and hydrogen atom transfer catalyst.The synergism of the reversible Nd^(2+)/Nd^(3+)and Cl^(ˉ)/Cl˙redox pairs significantly enhances overall photocatalytic efficiency.The in vitro anticancer activity of 4-alkylated products was evaluated by using the CCK8assay against both human choroidal melanoma(MUM-2B)and lung cancer(A549)cell.Compound 3da showed approximately triple the potency of 5-fluorouracil.展开更多
Cerium and cobalt loaded Co-Ce/TiO_(2)catalyst prepared by impregnation method was investigated for photothermal catalytic toluene oxidation.Based on catalyst characterizations(XPS,EPR and H2-TPR),redox cycle between ...Cerium and cobalt loaded Co-Ce/TiO_(2)catalyst prepared by impregnation method was investigated for photothermal catalytic toluene oxidation.Based on catalyst characterizations(XPS,EPR and H2-TPR),redox cycle between Co and TiO_(2)(Co^(2+)+Ti^(4+)↔Co^(3+)+Ti^(3+))results in the formation of Co^(3+),Ti^(3+)and oxygen vacancies,which play important roles in toluene catalytic oxidation reaction.The introduction of Ce brings in the dual redox cycles(Co^(2+)+Ti^(4+)↔Co^(3+)+Ti^(3+),Co^(2+)+Ce4+↔Co^(3+)+Ce3+),further promoting the elevation of reaction sites amount.Under full spectrum irradiation with light intensity of 580mW/cm^(2),Co-Ce/TiO_(2)catalyst achieved 96%of toluene conversion and 73%of CO_(2)yield,obviously higher than Co/P25 and Co/TiO_(2).Co-Ce/TiO_(2)efficiently maintains 10-hour stability test under water vapor conditions and exhibits better photothermal catalytic performance than counterparts under different wavelengths illumination.Photothermal catalytic reaction displays improved activities compared with thermal catalysis,which is attributed to the promotional effect of light including photocatalysis and light activation of reactive oxygen species.展开更多
Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemist...Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemistry of O3-type layered oxide cathode materials.This work systematically investigates the effect of Fe doping on the anionic oxygen redox chemistry and electrochemical reactions in O3-NaNi_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1)O_(2).The results of the density functional theory(DFT)calculations indicate that the electrons of the O 2p occupy a higher energy level.In the ex-situ X-ray photoelectron spectrometer(XPS)of O 1s,the addition of Fe facilitates the lattice oxygen(O^(n-))to exhibit enhanced activity at 4.45 V.The in-situ X-ray diffraction(XRD)demonstrates that the doping of Fe effectively suppresses the Y phase transition at high voltages.Furthermore,the Galvanostatic Intermittent Titration Technique(GITT)data indicate that Fe doping significantly increases the Na~+migration rate at high voltages.Consequently,the substitution of Fe can elevate the cut-off voltage to 4.45 V,thereby facilitating electron migration from O^(2-).The redox of O^(2-)/O^(n-)(n<2)contributes to the overall capacity.O3-Na(Ni_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1))_(0.92)Fe_(0.08)O_(2)provides an initial discharge specific capacity of 180.55 mA h g^(-1)and71.6%capacity retention at 0.5 C(1 C=240 mA g^(-1)).This work not only demonstrates the beneficial impact of Fe substitution for promoting the redox activity and reversibility of O^(2-)in 03-type layered oxides,but also guarantees the structural integrity of the cathode materials at high voltages(>4.2 V).It offers a novel avenue for investigating the anionic redox reaction in O3-type layered oxides to design advanced cathode materials.展开更多
Sodium-ion batteries (SIBs) with organic electrodes are an emerging research direction due to the sustainability of organic materials based on elements like C,H,O,and sodium ions.Currently,organic electrode materials ...Sodium-ion batteries (SIBs) with organic electrodes are an emerging research direction due to the sustainability of organic materials based on elements like C,H,O,and sodium ions.Currently,organic electrode materials for SIBs are mainly used as cathodes because of their relatively high redox potentials(>1 V).Organic electrodes with low redox potential that can be used as anode are rare.Herein,a novel organic anode material (tetrasodium 1,4,5,8-naphthalenetetracarboxylate,Na_(4)TDC) has been developed with low redox potential (<0.7 V) and excellent cyclic stability.Its three-sodium storage mechanism was demonstrated with various in-situ/ex-situ spectroscopy and theoretical calculations,showing a high capacity of 208 mAh/g and an average decay rate of merely 0.022%per cycle.Moreover,the Na_(4)TDC-hard carbon composite can further acquire improved capacity and cycling stability for 1200 cycles even with a high mass loading of up to 20 mg cm^(-2).By pairing with a thick Na_(3)V_(2)(PO_(4))_(3)cathode (20.6 mg cm^(-2)),the as-fabricated full cell exhibited high operating voltage (2.8 V),excellent rate performance and cycling stability with a high capacity retention of 88.7% after 200 cycles,well highlighting the Na_(4)TDC anode material for SIBs.展开更多
基金supported by the University of Seoul’s 2025 Research Fund.
文摘Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.
基金supported by Guangdong Basic and Applied Basic Research Foundation(2025A1515011362)the National Natural Science Foundation of China(52102304,52172238)Open Project of Shaanxi Laboratory of Aerospace Power(2021SXSYS-01-03).
文摘Pb-Sn mixed perovskite solar cells(PSCs)are crucial components for realizing efficient all-perovskite tandem devices.However,their efficiency and stability are severely limited by oxidative degradation(Sn^(4+)formation)and metallic defects(Sn^(0)/Pb^(0)).In addition,the rapid and uncontrolled Sn^(2+)nucleation kinetics result in nonuniform crystallization.Herein,we introduce a natural redox shuttle glutathione(GSH)in Pb-Sn mixed PSCs,achieving regenerable antioxidation and crystallization regulation simultaneously.The reversible redox reactions between GSH and glutathione disulfide(GSSG)enable the self-healing of Sn^(4+)and Sn^(0)/Pb^(0)impurities,creating a regenerable antioxidation protective shell at the perovskite interfaces.Meanwhile,the strong coordination between GSH and perovskite regulates the crystallization process,optimizing the nucleation and crystallization kinetics.Furthermore,the GSH incorporation creates a high-quality charge separation junction at the perovskite/hole transport layer,facilitating carrier separation and extraction.The optimized Pb-Sn PSCs exhibit impressive power conversion efficiencies(PCEs)of up to 23.71%.The champion all-perovskite tandem PSCs with GSH achieve a PCE of 28.49%and retain 90%of the initial PCE after 560 h of continuous illumination.This work establishes a new nature-inspired redox shuttling strategy and elucidates its working mechanism,advancing the development of efficient and stable all-perovskite tandem solar cells.
基金the financial support from the National Natural Science Foundation of China (22109127)the Chinese Postdoctoral Science Foundation (2021M702666)+2 种基金the Research Fund of the State Key Laboratory of Solidification Processing (NPU),China (Grant No.2023-TS-02)The financial support from the Youth Project of"Shaanxi High-level Talents Introduction Plan"the Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) are also sincerely appreciated
文摘Photo-assisted lithium–sulfur batteries(PALSBs)offer an eco-friendly solution to address the issue of sluggish reaction kinetics of conventional LSBs.However,designing an efficient photoelectrode for practical implementation remains a significant challenge.Herein,we construct a free-standing polymer–inorganic hybrid photoelectrode with a direct Z-scheme heterostructure to develop high-efficiency PALSBs.Specifically,polypyrrole(PPy)is in situ vapor-phase polymerized on the surface of N-doped TiO_(2) nanorods supported on carbon cloth(N-TiO_(2)/CC),thereby forming a well-defined p–n heterojunction.This architecture efficiently facilitates the carrier separation of photo-generated electron–hole pairs and significantly enhances carrier transport by creating a built-in electric field.Thus,the PPy@N-TiO_(2)/CC can simultaneously act as a photocatalyst and an electrocatalyst to accelerate the reduction and evolution of sulfur,enabling ultrafast sulfur redox dynamics,as convincingly validated by both theoretical simulations and experimental results.Consequently,the PPy@N-TiO_(2)/CC PALSB achieves a high discharge capacity of 1653 mAh g^(−1),reaching 98.7%of the theoretical value.Furthermore,5 h of photo-charging without external voltage enables the PALSB to deliver a discharge capacity of 333 mAh g^(−1),achieving dual-mode energy harvesting capabilities.This work successfully integrates solar energy conversion and storage within a rechargeable battery system,providing a promising strategy for sustainable energy storage technologies.
基金financially supported by National Natural Science Foundation of China(No.22302155)the Fundamental Research Funds of the Center Universities(No.D5000240188)the research program of ZJUT(YJY-ZS-20240001)。
文摘Metal halide perovskites(MHPs)with striking electrical and optical properties have appeared at the forefront of semiconductor materials for photocatalytic redox reactions but still suffer from some intrinsic drawbacks such as inferior stability,severe charge-carrier recombination,and limited active sites.Heterojunctions have recently been widely constructed to improve light absorption,passivate surface for enhanced stability,and promote charge-carrier dynamics of MHPs.However,little attention has been paid to the review of MHPs-based heterojunctions for photocatalytic redox reactions.Here,recent advances of MHPs-based heterojunctions for photocatalytic redox reactions are highlighted.The structure,synthesis,and photophysical properties of MHPs-based heterojunctions are first introduced,including basic principles,categories(such as Schottky junction,type-I,type-II,Z-scheme,and S-scheme junction),and synthesis strategies.MHPs-based heterojunctions for photocatalytic redox reactions are then reviewed in four categories:H2evolution,CO_(2)reduction,pollutant degradation,and organic synthesis.The challenges and prospects in solar-light-driven redox reactions with MHPs-based heterojunctions in the future are finally discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.52202282,52402054,22471283,and 52202327)Natural Science Foundation of Tianjin City(Grant Nos.22JCYBJC00040,24JCQNJC00970)。
文摘High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs generally enforcing stoichiometric symmetry(Ni=Mn)yield low Fe redox activity.Herein,we propose a valence engineering strategy that breaks conventional Ni/Mn stoichiometry to reconfigure Fe's local chemical environment and unlock unprecedented redox depth.Density functional theory(DFT)calculations reveal that the designed NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode exhibits a reduced Bader charge on Fe(1.598 vs.1.638 in NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2))and elevated Fe 3d orbital energy,signifying enhanced Fe redox activity.This configuration enables an exceptional Fe^(2.60+)/Fe^(3.88+)redox(1.28 e~-per Fe),delivering a reversible capacity of184.3 mAh g^(-1)within 2-4.2 V at 0.2 C,markedly exceeding the benchmark NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(161.3 mAh g^(-1))with low reaction depth of Fe^(3.01+)/Fe^(3.61+).The intensified cationic redox reaction enables an ultrahigh energy density of 596 Whkg-1.The NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode demonstrates robust performance over a broad temperature range from-15℃to 60℃.In situ and ex situ characterizations unveil a reversible O3■P3■OP2 phase transition with minimal volume change(1.88%)that circumvents detrimental deleterious O'3 intermediates and intragranular cracking.This work establishes valence engineering as a paradigm to consolidate cationic redox reaction in high-energy layered sodium oxide cathodes.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20250050)the National Natural Science Foundation of China(22472111,12275189)+4 种基金the National Key Research Program of China(2022YFA1503101)the Postdoctoral Fellowship Program of CPSF(GZC20250614)Jiangsu Funding Program for Excellent Postdoctoral Talent(2025ZB299)Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 Project。
文摘Lithium-sulfur(Li-S)batteries hold great promise for high-energy–density energy storage applications but are plagued by the severe shuttle effect and sluggish conversion kinetics of lithium polysulfides(Li PSs).We herein report a d-p-f orbital coupling strategy to tackle these critical challenges by incorporating Eu 4f orbitals to activate both metallic(Ni)and non-metallic(Se)sites of Ni Se.The imported Eu atoms could induce essential Ni 3d and Se 4p orbital reconstruction through gradient d-p-f coupling,thereby optimizing the band center alignment between Ni Se and Li PSs.Such electronic reconstruction strengthens both d-p hybridization between Ni and Li PSs and s-p hybridization between Se and Li PSs,which can not only enhance the chemisorption affinity toward Li PSs but also accelerate interfacial charge transfer kinetics,leading to suppressed shuttle effect and boosted Li PSs conversion kinetics.Therefore,the Li-S batteries assembled with Eu incorporated Ni Se deliver exceptional electrochemical performance with a high specific capacity of 896.2 m Ah g^(-1)at 4 C and a retained areal capacity of 5.66 m Ah cm^(-2)under a high sulfur loading of 5.94 mg cm^(-2)after 100 cycles.This work underscores the critical role of rare-earth 4f orbital coupling for modulating the active sites to construct high-efficiency electrocatalysts for Li-S batteries and beyond.
基金supported by the National Natural Science Foundation of China(22379084)Department of Science and Technology of Guangdong Province(211233812024)Shenzhen Science and Technology Program(JCYJ20220818101007016,KJZD20240903101303005)。
文摘Lithium-rich manganese-based cathode materials,as promising candidates for next-generation highenergy–density lithium-ion batteries due to their high specific capacity(>250 mAh g^(-1))and costeffectiveness,are limited by severe capacity decay and voltage fade driven by irreversible structural transitions and oxygen release during cycling.Here,we report a Ti/Si dual-element modification strategy for cobalt-free Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(LNMO)cathodes.The Ti/Si co-modified TS-LNMO cathode demonstrates superior structural stability and electrochemical performance.Bulk Ti^(4+)doping stabilizes the oxygen framework via robust Ti–O bonds and enhances the lattice oxygen redox reversibility,while an in situ formed Li_(2) SiO_(3) layer suppresses interfacial side reactions,enhances lithium-ion diffusion,and prevents HF-induced erosion.As a result,the TS-LNMO cathode achieves 90%capacity retention after 200 cycles at 0.5 C and maintains -80%capacity in full cells cycled to 4.8 V.Additionally,the TS-LNMO cathode exhibits impressive rate performance even at a high rate of 5 C.This work offers an effective strategy for advancing cobalt-free,high-performance lithium-rich cathodes for sustainable energy applications.
基金financially supported by the National Natural Science Foundation of China(no.52172209)the Shenzhen International Cooperative Research Project(GJHZ20240218113607014)。
文摘The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stability compared to conventional doping modifications,rational element selection for optimizing OR reversibility remains unexplored.Here,we propose an entropy engineering design paradigm for “oxygen-anchoring”,where optimal cation electronegativity(>Mn,1.55)and d(3d/4d)-p orbital hybridization synergistically enhance transition metal–oxygen(TM–O)covalency and stabilize the O2p state.Two high-entropy Li-rich layered oxides:Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Al_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTANM)and Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTCNM)were synthesized using partial nano-scale precursors and comparatively evaluated.MTCNM exhibits enhanced electrochemical performance and superior oxygen stability compared to MTANM by replacing Al with higher-electronegativity Cu,which possesses improved orbital overlap with oxygen.Both experiments and density functional theory(DFT)calculations demonstrate that element selection changes the covalency of TM–O through altered electronegativity and d orbitals-p orbitals(d-p)hybridization.Further stepwise screening selected the optimal elemental combination Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Cr_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)Ru_(0.02)O_(2)(CCNMR),which achieved near 100%capacity retention after 150 cycles at 1 C,50℃,with its voltage decay effectively suppressed.This work establishes a rational element-screening paradigm for entropy-stabilized OR chemistry in high-energy cathodes.
基金support from Guangdong Basic and Applied Basic Research Foundation(2020B1515420001 and 2023B1515040027)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(23yxqntd002)the Postdoctoral Fellowship Program of CPSF(GZC20242066).
文摘Redox-active covalent organic polymers(COPs)have emerged as appealing renewable electrode materials for next-generation Li-ion batteries,but their performance is limited by insufficient redox sites and inadequate Li-ion diffusion.Here,we develop a novel class of mesoporous covalent organic polymer(namely TF-Azo-COP)bearing multiple redox sites and explore its first use as efficient 18-electron-redox anodes for superior Li-ion storage in both coin-type and fiber-type batteries.The newly produced TF-Azo-COP involves three types of active sites including C=N in triazines and imines,N=N in azo,and C6-ring aromatics to enable 18-Li-ion storage on one repeatable segment,while affording extendedπ-conjugation for fast electron transfer and a pore size of~2.5 nm for facilitated ion diffusion with a high coefficient up to~10^(-10)cm^(2)s^(-1)—superior to some reported organic electrodes.Meriting from the above,pairing TF-Azo-COP with metal Li endows a coin cell with good cycling stability and a large reversible capacity of 795.4 mAh g^(-1)at 0.1 A g^(-1)—representing one of the best performances among reported organic electrodes.When coupled with fiber-shaped LiFePO_(4)cathodes,the assembled fiber cell delivers an excellent combination of linear capacity(0.23 mAh cm^(-1)),energy density(0.55 mWh cm^(-1)),cycling stability(250 cycles),and good flexibility.
基金financially supported by the Nation Key R&D Program China(2018YFA0703200)the Key Research and Development Program of Hubei Province(2022BAA026)+1 种基金the National Natural Science Foundation of China(51772110)the Open Research Fund(2024JYBKF01)of Key Laboratory of Material Chemistry for Energy Conversion and Storage(HUST),Ministry of Education。
文摘Sluggish kinetics coupled with parasitic shuttling reactions are pivotal challenges hindering the performance of lithium-sulfur(Li-S)batteries.Improving areal capacity and cyclability of Li-S batteries can be achieved by addressing these challenges.A composite sulfur host material is synthesized herein by in situ anchoring ultrafine cobalt-iron phosphide nanoparticles(5-7 nm)onto a hollow mesoporous carbon sphere(HMCS)framework.This strategy achieved exceptional spatial restriction and a high density of catalytically active sites through the encapsulation of sulfur within a hollow-structured framework.Specifically,HMCS expedites rapid Li_(2)S nucleation kinetics,while CoFeP facilitates robust Li_(2)S dissolution kinetics by mitigating decomposition barriers.This synergistic integration equips CoFeP@HMCS with robust bi-directional catalytic activity,significantly promoting interracial charge-transfer,facilitate sulfu r multistep catalytic conversion,and inhibiting shuttling.Consequently,the battery exhibits excellent rate performance(991 mA h g^(-1) at 5.0 C)and retains a high areal capacity of 6.06 mA h cm^(-2) after 200 cycles under a high areal sulfur loading of 8.2 mg cm^(-2) but a low electrolyte/sulfur ratio of 4.8μL mg^(-1).This work contributes to enhancing the practical specific capacity of lithium-sulfur batteries and deepens the understanding of catalysts enabling bidirectional electrocatalytic sulfur conversion.
基金supported by the National Natural Science Foundation of China(22202182)the Key Technology R&D Program of Henan Province(242102240088)the China Postdoctoral Science.
文摘Redox mediators(RMs)represent the most promising strategy to address the sluggish kinetics of lithium-oxygen(Li-O_(2))batteries.To achieve high-energy and cost-effective Li-O_(2)batteries,carbon materials are typically regarded as ideal cathodes in these systems.However,the impact of their surface properties—which often regulate specific discharge pathways—on the RM-mediated oxygen reduction reaction(ORR)remains unclear.In this study,CNTs electrodes with different surface properties are fabricated.Results suggest that CNTs with more surface defects not only promote the unmediated discharge pathway even in RMs-involved battery systems but also exacerbate the corrosion of carbon cathodes.This,in turn,leads to the undesired accumulation of Li_(2)O_(2)and Li_(2)CO_(3)on the cathode surface,which hinders effective and continuous electron transfer between the cathode and RMs,ultimately decreasing the catalytic activity of RMs.As a result,the discharge capacity of the battery is seriously diminished,especially at large current densities.These findings underscore the significance of surface engineering in advancing the performance of RMs-assisted Li-O_(2)batteries.
基金financially supported by the National Natural Science Foundation of China(22578113 and 52371187)Natural Science Foundation of Hebei Province(E2024209029)Science and Technology Planning Project of Tangshan City(24130228C)。
文摘Vanadium redox flow battery(VRFB),as a potential technology for next-generation energy storage system,is restricted by the slow redox kinetics of vanadium ions.Implementing interface engineering strategies to functionalize the surface of MXene can effectively address this challenge.Herein,a Nb_(2)CT_(x)/Nb_(2)O_(5)Schottky heterostructure is constructed to facilitate high-speed charge transfer at the VRFB electrode through controllable in-situ oxidation.The loading amount of Nb_(2)O_(5) nanorods on the surface of Nb_(2)CT_(x) nanosheets was regulated by varying the hydrothermal reaction time.Density functional theory calculations confirm that the Schottky barrier formed between Nb_(2)CT_(x) and Nb_(2)O_(5) leads to the establishment of an internal electric field and reconfigures the electronic structure of surficial active sites.The rich pore structure of Nb_(2)CT_(x)/Nb_(2)O_(5) electrode effectively shortens the diffusion path for vanadium ions,while its excellent hydrophilicity enhances the interaction between vanadium ions and the electrodes.Compared with graphite felt,Nb_(2)CT_(x)/Nb_(2)O_(5)-2@GF cell shows a 20%increase in energy efficiency(EE)at 150 mA cm^(-2) cycling,reaching 75%,while maintaining stable performance for over 800 cycles.This means a significant advancement in the development of high-performance electrodes for VRFBs.This work offers an efficient and scalable strategy for the design of redox flow batteries.
基金the National Natural Science Foundation of China(No.22271060),The Department of Chemistry at Fudan University and College of Chemistry and Chemical Engineering at Ningxia University is gratefully acknowledged.
文摘Photoredox catalysis has made significant advances in stateof-the-art chemical synthesis,drawing energy from inexhaustible light and enabling various organic transformations to occur under mild reaction conditions.Over the past few years,a variety of homogeneous and heterogeneous photocatalysts have been applied in the photoredox catalysis.Heterogeneous photoredox catalysis offers advantages such as easy separation and superior recyclability compared to homogeneous counterparts,although homogenous catalysts are usually associated with higher activities and selectivity.From a practical perspective,an optimal photoredox catalytic system would integrate the advantages of both homogeneous and heterogeneous cases.
基金The National Key R&D Program of China under contract No. 2023YFC28 11305the Scientific Research Fund of the Second Institute of Oceanography,MNR under contract No. SZ2405the Impact and Response of Antarctic Seas to Climate Change under contract No. IRASCC
文摘Research on changes in the redox conditions of bottom waters is essential for understanding deep water circulation,global ocean currents,climate change,and ecosystem health.Through sedimentary geological methods,a deeper understanding of the complex relationships between various environmental changes can be achieved,providing detailed evidence and theoretical support for global climate change research.The Ross Sea in Antarctica plays a key role in the formation of Antarctic bottom water(AABW),and the complex climate changes since the last glacial maximum(LGM)make it particularly significant for study.This research analyzes core ANT32-RB16C from the Ross Sea using geochemical proxies such as major and trace elements,grain size,and redox-sensitive indicators like Mn/Ti,Co/Ti,Mo/Ti,Cd/Ti,U/Th,and Ni/Co molar concentration ratios.Combining this data with a previously established chronological framework,the study explores the evolution of redox conditions in the Ross Sea’s deep waters since the LGM.The results show that the deep waters have remained oxygen-rich since the LGM,with significant changes in four stages.Stage 1(24.7–15.7 cal ka BP):Strong oxidizing conditions,likely due to enhanced formation of Ross Sea bottom water(RSBW),increasing oxygen levels.Stage 2(15.7–4.5 cal ka BP):Weakened oxidizing conditions as temperatures rose and ice shelves retreated,increasing primary productivity and depleting oxygen.Stage 3(4.5–1.5 cal ka BP):Continued decline in oxidizing conditions,possibly linked to high primary productivity and oxygen consumption.Stage 4(1.5 cal ka BP to present):A rapid recovery of oxidizing conditions,likely driven by temperature drops,increased RSBW formation,and decreased productivity.
基金Supported by the Special Educating Project of the Talent for Carbon Peak and Carbon Neutrality of University of Chinese Academy of Sciences(E3E56501A2)。
文摘Redox flow batteries have gained wide attention at home and abroad as a long-duration energy storage technology with the advantages of high safety,long lifespan,mutual independence of capacity and power,and easy recycling.However,the current battery management technology faces significant challenges,and there is room for development.Digital twin(DT),as a technology that collectively senses,evaluates,predicts,and optimizes characteristics,is promising to contribute to redox flow batteries’operation,maintenance,and management.This paper begins with a brief description of redox flow batteries,followed by a short explanation of the concept and application of DTs.DTs have already made some progress in the field of batteries,and can be applied to solve the problems of redox flow batteries in terms of thermal management and system optimization.Finally,the paper analyzes the combination of redox flow battery and DT architecture,which is expected to contribute to developing DT technology for redox flow batteries.
基金supported by grants from the Provincial Natural Science Foundation of Hunan(No.2023JJ60335)。
文摘The first example of Nd@C_(3)N_(4)-photoredox/chlorine dual catalyzed alkylation with unactivated alkanes as the alkyl sources has been developed,which allows for the synthesis of various 4-alkylated cyclic sulfonyl ketimines.In this process,chlorine functions as both a redox and hydrogen atom transfer catalyst.The synergism of the reversible Nd^(2+)/Nd^(3+)and Cl^(ˉ)/Cl˙redox pairs significantly enhances overall photocatalytic efficiency.The in vitro anticancer activity of 4-alkylated products was evaluated by using the CCK8assay against both human choroidal melanoma(MUM-2B)and lung cancer(A549)cell.Compound 3da showed approximately triple the potency of 5-fluorouracil.
基金supported by the Science and Technology Planning Project of Xiamen(No.3502Z20226022)the National Natural Science Foundation of China(Nos.22376193 and 22176187).
文摘Cerium and cobalt loaded Co-Ce/TiO_(2)catalyst prepared by impregnation method was investigated for photothermal catalytic toluene oxidation.Based on catalyst characterizations(XPS,EPR and H2-TPR),redox cycle between Co and TiO_(2)(Co^(2+)+Ti^(4+)↔Co^(3+)+Ti^(3+))results in the formation of Co^(3+),Ti^(3+)and oxygen vacancies,which play important roles in toluene catalytic oxidation reaction.The introduction of Ce brings in the dual redox cycles(Co^(2+)+Ti^(4+)↔Co^(3+)+Ti^(3+),Co^(2+)+Ce4+↔Co^(3+)+Ce3+),further promoting the elevation of reaction sites amount.Under full spectrum irradiation with light intensity of 580mW/cm^(2),Co-Ce/TiO_(2)catalyst achieved 96%of toluene conversion and 73%of CO_(2)yield,obviously higher than Co/P25 and Co/TiO_(2).Co-Ce/TiO_(2)efficiently maintains 10-hour stability test under water vapor conditions and exhibits better photothermal catalytic performance than counterparts under different wavelengths illumination.Photothermal catalytic reaction displays improved activities compared with thermal catalysis,which is attributed to the promotional effect of light including photocatalysis and light activation of reactive oxygen species.
基金financial support from the Natural Science Foundation of Shandong Province of China(ZR2023ME051,ZR2019MEM020)。
文摘Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemistry of O3-type layered oxide cathode materials.This work systematically investigates the effect of Fe doping on the anionic oxygen redox chemistry and electrochemical reactions in O3-NaNi_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1)O_(2).The results of the density functional theory(DFT)calculations indicate that the electrons of the O 2p occupy a higher energy level.In the ex-situ X-ray photoelectron spectrometer(XPS)of O 1s,the addition of Fe facilitates the lattice oxygen(O^(n-))to exhibit enhanced activity at 4.45 V.The in-situ X-ray diffraction(XRD)demonstrates that the doping of Fe effectively suppresses the Y phase transition at high voltages.Furthermore,the Galvanostatic Intermittent Titration Technique(GITT)data indicate that Fe doping significantly increases the Na~+migration rate at high voltages.Consequently,the substitution of Fe can elevate the cut-off voltage to 4.45 V,thereby facilitating electron migration from O^(2-).The redox of O^(2-)/O^(n-)(n<2)contributes to the overall capacity.O3-Na(Ni_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1))_(0.92)Fe_(0.08)O_(2)provides an initial discharge specific capacity of 180.55 mA h g^(-1)and71.6%capacity retention at 0.5 C(1 C=240 mA g^(-1)).This work not only demonstrates the beneficial impact of Fe substitution for promoting the redox activity and reversibility of O^(2-)in 03-type layered oxides,but also guarantees the structural integrity of the cathode materials at high voltages(>4.2 V).It offers a novel avenue for investigating the anionic redox reaction in O3-type layered oxides to design advanced cathode materials.
基金National Key Research and Development Program of China (2022YFB2402200)National Natural Science Foundation of China (22225201,22379028)+2 种基金Fundamental Research Funds for the Central Universities (20720220010)Shanghai Pilot Program for Basic Research–Fudan University 21TQ1400100 (21TQ009)Key Basic Research Program of Science and Technology Commission of Shanghai Municipality (23520750400)。
文摘Sodium-ion batteries (SIBs) with organic electrodes are an emerging research direction due to the sustainability of organic materials based on elements like C,H,O,and sodium ions.Currently,organic electrode materials for SIBs are mainly used as cathodes because of their relatively high redox potentials(>1 V).Organic electrodes with low redox potential that can be used as anode are rare.Herein,a novel organic anode material (tetrasodium 1,4,5,8-naphthalenetetracarboxylate,Na_(4)TDC) has been developed with low redox potential (<0.7 V) and excellent cyclic stability.Its three-sodium storage mechanism was demonstrated with various in-situ/ex-situ spectroscopy and theoretical calculations,showing a high capacity of 208 mAh/g and an average decay rate of merely 0.022%per cycle.Moreover,the Na_(4)TDC-hard carbon composite can further acquire improved capacity and cycling stability for 1200 cycles even with a high mass loading of up to 20 mg cm^(-2).By pairing with a thick Na_(3)V_(2)(PO_(4))_(3)cathode (20.6 mg cm^(-2)),the as-fabricated full cell exhibited high operating voltage (2.8 V),excellent rate performance and cycling stability with a high capacity retention of 88.7% after 200 cycles,well highlighting the Na_(4)TDC anode material for SIBs.
