Proton exchange membrane fuel cell(PEMFC)is a promising clean energy source,but its performance and stability are vulnerable to the negative effects of humidity conditions.The gas diffusion substrate(GDS)plays a pivot...Proton exchange membrane fuel cell(PEMFC)is a promising clean energy source,but its performance and stability are vulnerable to the negative effects of humidity conditions.The gas diffusion substrate(GDS)plays a pivotal role in regulating the moisture and gas transport.The single pore structure of traditionally designed GDS often leads to the pathway competition between moisture and gas,which effects the efficiency of fuel cells.In this study,we report on a hierarchical fibrous paper with tunable hierarchical pores for a sustainable GDS.This design offers gas permeability under wet conditions,by separating the gas pathway from the moisture pathway,thus mitigating their pathway competition.In addition,this paper forms a multi-scale scaffold that absorbs moisture under high humidity conditions and releases it under dry conditions.It is allowed to maintain an optimal internal humidity and further enhances the humidity adaptability.Furthermore,the carbon footprint is only 15.97%,significantly lower than commercial alternatives.This feature makes it a sustainable solution to stabilize PEMFCs under diverse humidity conditions.展开更多
Although their cost-effectiveness and intrinsic safety,aqueous zinc-ion batteries suffer from notorious side reactions including hydrogen evolution reaction,Zn corrosion and passivation,and Zn dendrite formation on th...Although their cost-effectiveness and intrinsic safety,aqueous zinc-ion batteries suffer from notorious side reactions including hydrogen evolution reaction,Zn corrosion and passivation,and Zn dendrite formation on the anode.Despite numerous strategies to alleviate these side reactions have been demonstrated,they can only provide limited performance improvement from a single aspect.Herein,a triple-functional additive with trace amounts,ammonium hydroxide,was demonstrated to comprehensively protect zinc anodes.The results show that the shift of electrolyte pH from 4.1 to 5.2 lowers the HER potential and encourages the in situ formation of a uniform ZHS-based solid electrolyte interphase on Zn anodes.Moreover,cationic NH^(4+)can preferentially adsorb on the Zn anode surface to shield the“tip effect”and homogenize the electric field.Benefitting from this comprehensive protection,dendrite-free Zn deposition and highly reversible Zn plating/stripping behaviors were realized.Besides,improved electrochemical performances can also be achieved in Zn//MnO_(2)full cells by taking the advantages of this triple-functional additive.This work provides a new strategy for stabilizing Zn anodes from a comprehensive perspective.展开更多
Aqueous zinc-ion batteries(AZIBs)are promising for energy storage.However,Zn anode instability—caused by dendrite growth,hydrogen evolution reaction(HER),and by-product formation—limits their practical viability.HER...Aqueous zinc-ion batteries(AZIBs)are promising for energy storage.However,Zn anode instability—caused by dendrite growth,hydrogen evolution reaction(HER),and by-product formation—limits their practical viability.HER,in particular,accelerates Zn consumption,disrupts electrode integrity,and induces local alkalization,exacerbating passivation.Conventional strategies emphasize electrolyte formulation and surface passivation,yet few address the underlying electronic origin of HER on Zn.Here we report a catalysis-inspired strategy that electronically modulates Zn reactivity via d-band center engineering to intrinsically suppress HER.By introducing oxalic acid(OA)as a molecular additive,we achieve a significant downward shift in the Zn d-band center(from–6.896 to–7.062 eV),weakening hydrogen adsorption and fundamentally reducing HER activity.In parallel,OA disrupts the Zn^(2+)solvation structure by displacing coordinated SO_(4)^(2-)anions,suppressing interfacial by-product formation.These dual effects yield unprecedented performance:Zn||Zn symmetric cells operate stably for over 3500 h;Zn||Cu cells exhibit 99.41%Coulombic efficiency over 1500 cycles;and Zn||I2 cell retain 92.8%capacity after 10,000 cycles;the 1.3 Ah Zn||I2 pouch cell presents good cyclability.This work pioneers a surface electronic tuning paradigm in battery design,extending catalytic d-band theory to electrochemical interfaces for HER suppression and interfacial stabilization in aqueous metal batteries.展开更多
Aqueous zinc-ion batteries(AZIBs)are promising for large-scale energy storage,but their development is plagued by inadequate cycle life.Here,for the first time,we reveal an unusual phenomenon of cathodic underpotentia...Aqueous zinc-ion batteries(AZIBs)are promising for large-scale energy storage,but their development is plagued by inadequate cycle life.Here,for the first time,we reveal an unusual phenomenon of cathodic underpotential deposition(UPD)of Zn,which is highly irreversible and considered the origin of the inferior cycling stability of AZIBs.Combining experimental and theoretical simulation approaches,we propose that the UPD process agrees with a two-dimensional nucleation and growth model,following a thermodynamically feasible mechanism.Furthermore,the universality of Zn UPD is identified in systems,including VO_(2)//Zn,TiO_(2)//Zn,and SnO_(2)//Zn.In practice,we propose and successfully implement removing cathodic Zn UPD and substantially mitigate the degradation of the battery by controlling the end-ofdischarge voltage.This work provides new insights into AZIBs degradation and brings the cathodic UPD behavior of rechargeable batteries into the limelight.展开更多
Lithium metal anodes(LMAs)have been considered the ultimate anode materials for next-generation batteries.However,the uncontrollable lithium dendrite growth and huge volume expansion that can occur during charge and d...Lithium metal anodes(LMAs)have been considered the ultimate anode materials for next-generation batteries.However,the uncontrollable lithium dendrite growth and huge volume expansion that can occur during charge and discharge seriously hinder the practical application of LMAs.Metal–organic framework(MOF)materials,which possess the merits of huge specific surface area,excellent porosity,and flexible composition/structure tunability,have demonstrated great potential for resolving both of these issues.This article first explores the mechanism of lithium dendrite formation as described by four influential models.Subsequently,based on an in-depth understanding of these models,we propose potential strategies for utilizing MOFs and their derivatives to suppress lithium dendrite growth.We then provide a comprehensive review of research progress with respect to various applications of MOFs and their derivatives to suppress lithium dendrites and inhibit volume expansion.The paper closes with a discussion of perspectives on future modifications of MOFs and their derivatives to achieve stable and dendrite-free lithium metal batteries.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U23A6005,22208112,and 32171721)the National Natural Science Foundation of China(No.22308109)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2024A1515010678)the Fundamental Research Funds for the Central Universities(SCUT:2023ZYGXZR045)the State Key Laboratory of Pulp&Paper Engineering(Nos.2023ZD01,2023C02).
文摘Proton exchange membrane fuel cell(PEMFC)is a promising clean energy source,but its performance and stability are vulnerable to the negative effects of humidity conditions.The gas diffusion substrate(GDS)plays a pivotal role in regulating the moisture and gas transport.The single pore structure of traditionally designed GDS often leads to the pathway competition between moisture and gas,which effects the efficiency of fuel cells.In this study,we report on a hierarchical fibrous paper with tunable hierarchical pores for a sustainable GDS.This design offers gas permeability under wet conditions,by separating the gas pathway from the moisture pathway,thus mitigating their pathway competition.In addition,this paper forms a multi-scale scaffold that absorbs moisture under high humidity conditions and releases it under dry conditions.It is allowed to maintain an optimal internal humidity and further enhances the humidity adaptability.Furthermore,the carbon footprint is only 15.97%,significantly lower than commercial alternatives.This feature makes it a sustainable solution to stabilize PEMFCs under diverse humidity conditions.
基金supported by the National Key Research and Development Program of China(2019YFE0114400)the Guangdong Basic and Applied Basic Research Foundation(2021B1515120005)+7 种基金the National Natural Science Foundation of China(32171721)the Guangdong Basic and Applied Basic Research Foundation(2021B151512000)the Guangzhou Science and Technology Plan Project(202102020262)the State Key Laboratory of Pulp&Paper Engineering(2022C01),the State Key Laboratory of Pulp&Paper Engineering(202208)the Engineering and Physical Sciences Research Council(EPSRCEP/V027433/1EP/V027433/2EP/Y008707/1)。
文摘Although their cost-effectiveness and intrinsic safety,aqueous zinc-ion batteries suffer from notorious side reactions including hydrogen evolution reaction,Zn corrosion and passivation,and Zn dendrite formation on the anode.Despite numerous strategies to alleviate these side reactions have been demonstrated,they can only provide limited performance improvement from a single aspect.Herein,a triple-functional additive with trace amounts,ammonium hydroxide,was demonstrated to comprehensively protect zinc anodes.The results show that the shift of electrolyte pH from 4.1 to 5.2 lowers the HER potential and encourages the in situ formation of a uniform ZHS-based solid electrolyte interphase on Zn anodes.Moreover,cationic NH^(4+)can preferentially adsorb on the Zn anode surface to shield the“tip effect”and homogenize the electric field.Benefitting from this comprehensive protection,dendrite-free Zn deposition and highly reversible Zn plating/stripping behaviors were realized.Besides,improved electrochemical performances can also be achieved in Zn//MnO_(2)full cells by taking the advantages of this triple-functional additive.This work provides a new strategy for stabilizing Zn anodes from a comprehensive perspective.
基金supported by the National Natural Science Foundation of China(52204324 and 22409119)the National Key Research and Development Program of China(2024YFE0116300)+2 种基金the Key Research and Development Program of Hunan(2023SK2053)the China Postdoctoral Science Foundation(2024M751651)Shenzhen Science and Technology Innovation Commission(20231610276)for funding support.
文摘Aqueous zinc-ion batteries(AZIBs)are promising for energy storage.However,Zn anode instability—caused by dendrite growth,hydrogen evolution reaction(HER),and by-product formation—limits their practical viability.HER,in particular,accelerates Zn consumption,disrupts electrode integrity,and induces local alkalization,exacerbating passivation.Conventional strategies emphasize electrolyte formulation and surface passivation,yet few address the underlying electronic origin of HER on Zn.Here we report a catalysis-inspired strategy that electronically modulates Zn reactivity via d-band center engineering to intrinsically suppress HER.By introducing oxalic acid(OA)as a molecular additive,we achieve a significant downward shift in the Zn d-band center(from–6.896 to–7.062 eV),weakening hydrogen adsorption and fundamentally reducing HER activity.In parallel,OA disrupts the Zn^(2+)solvation structure by displacing coordinated SO_(4)^(2-)anions,suppressing interfacial by-product formation.These dual effects yield unprecedented performance:Zn||Zn symmetric cells operate stably for over 3500 h;Zn||Cu cells exhibit 99.41%Coulombic efficiency over 1500 cycles;and Zn||I2 cell retain 92.8%capacity after 10,000 cycles;the 1.3 Ah Zn||I2 pouch cell presents good cyclability.This work pioneers a surface electronic tuning paradigm in battery design,extending catalytic d-band theory to electrochemical interfaces for HER suppression and interfacial stabilization in aqueous metal batteries.
基金supported by the National Key Research and Development Program of China(2020YFA0715000 and 2016YFA0202603)the National Natural Science Foundation of China(51832004,51521001,and 22109029)。
文摘Aqueous zinc-ion batteries(AZIBs)are promising for large-scale energy storage,but their development is plagued by inadequate cycle life.Here,for the first time,we reveal an unusual phenomenon of cathodic underpotential deposition(UPD)of Zn,which is highly irreversible and considered the origin of the inferior cycling stability of AZIBs.Combining experimental and theoretical simulation approaches,we propose that the UPD process agrees with a two-dimensional nucleation and growth model,following a thermodynamically feasible mechanism.Furthermore,the universality of Zn UPD is identified in systems,including VO_(2)//Zn,TiO_(2)//Zn,and SnO_(2)//Zn.In practice,we propose and successfully implement removing cathodic Zn UPD and substantially mitigate the degradation of the battery by controlling the end-ofdischarge voltage.This work provides new insights into AZIBs degradation and brings the cathodic UPD behavior of rechargeable batteries into the limelight.
基金This work was supported by the Liaocheng University Ph.D.Start-up Foundation(318052012)China Postdoctoral Science Foundation(2022M721913)+6 种基金Engineering and Physical Sciences Research Council(EPSRCEP/V027433/3)UK Royal Society(IES/R2/212115IEC∖NSFC∖211019)UK Research and Innovation(UKRI)under the UK government's Horizon Europe funding guarantee(101077226EP/Y008707/1)Z.Du thanked the funding support from China Scholarship Council/University College London for the joint Ph.D.scholarship.
文摘Lithium metal anodes(LMAs)have been considered the ultimate anode materials for next-generation batteries.However,the uncontrollable lithium dendrite growth and huge volume expansion that can occur during charge and discharge seriously hinder the practical application of LMAs.Metal–organic framework(MOF)materials,which possess the merits of huge specific surface area,excellent porosity,and flexible composition/structure tunability,have demonstrated great potential for resolving both of these issues.This article first explores the mechanism of lithium dendrite formation as described by four influential models.Subsequently,based on an in-depth understanding of these models,we propose potential strategies for utilizing MOFs and their derivatives to suppress lithium dendrite growth.We then provide a comprehensive review of research progress with respect to various applications of MOFs and their derivatives to suppress lithium dendrites and inhibit volume expansion.The paper closes with a discussion of perspectives on future modifications of MOFs and their derivatives to achieve stable and dendrite-free lithium metal batteries.
