近年来,过渡金属氧化物已被认为是最有希望代替贵金属作为锂氧(Li-O2)电池阴极催化剂的材料。本文研究了一种由静电纺纤维煅烧后自发形成的MnO纳米颗粒作为Li-O2电池的高效催化剂。物性表征的结果显示成功合成了平均粒径为61.82 nm的Mn...近年来,过渡金属氧化物已被认为是最有希望代替贵金属作为锂氧(Li-O2)电池阴极催化剂的材料。本文研究了一种由静电纺纤维煅烧后自发形成的MnO纳米颗粒作为Li-O2电池的高效催化剂。物性表征的结果显示成功合成了平均粒径为61.82 nm的MnO纳米颗粒,为立方晶系结构,作为Li-O2电池阴极在500次循环中表现出优异的循环稳定性,首次充电过电位为0.46 V,在500 mA·g−1的高电流密度下实现了1000 h的稳定循环,优于大多数已报道的用于Li-O2电池的MnOx催化剂。In recent years, transition metal oxides have been considered the most promising materials to replace precious metals as cathode catalysts for lithium-oxygen batteries. This study investigates MnO nanoparticles that spontaneously form after calcining electrospun fibers as an efficient catalyst for lithium-oxygen (Li-O2) batteries. Physical characterization shows that MnO nanoparticles with an average particle size of 61.82 nm and a cubic crystal structure were successfully synthesized. They exhibit excellent cycling stability as a cathode in Li-O2 batteries, enduring over 500 cycles with an initial overpotential of 0.46 V. Concurrent, they also achieve stable cycling for 1000 hours at a high current density of 500 mA·g−1, outperforming most reported catalysts such as MnOx for Li-O2 batteries.展开更多
The application of lithium metal anodes is hindered by low Coulombic efficiency(CE),serious lithium dendrites and volume expansion.An MnO/Polypropylene(PP)composite separator was developed to regulate lithium metal de...The application of lithium metal anodes is hindered by low Coulombic efficiency(CE),serious lithium dendrites and volume expansion.An MnO/Polypropylene(PP)composite separator was developed to regulate lithium metal deposition behaviors through in situ forming stable artificial solid electrolyte interface(SEI)passivating layers.The concentration of MnO in the cells can be maintained at a constant based on quite low solubility of MnO in the liquid electrolyte,and the dissolved MnO can be reduced to produce Li_(2)O and Mn metal nanoparticles,which can not only function as nucleating seeds of lithium metal deposits but also repair the broken SEI layer.Dendritic-free Li deposits can be obtained by simple separator coating.It can also improve the electrochemical performance of lithium metal batteries.And it is benefit for applications of Li metal anodes.展开更多
Rational developing high-performance and economically efficient dual-functional oxygen electrocatalysts to drive the lumberly reactivity rates of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)in Zn-a...Rational developing high-performance and economically efficient dual-functional oxygen electrocatalysts to drive the lumberly reactivity rates of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)in Zn-air batteries is highly attractive,yet remains conceptually challenging.Herein,Ni/MnO heterostructure nanosheets and nanoparticles firmly anchored onto the N-doped carbon nanofibers(noted as Ni/MnO@N-C NS/NFs)for efficient bifunctional ORR/OER electrocatalysis are designed and realized through a facile electrospinning-pyrolysis-etching strategy.The epitaxial in situ grown Ni/MnO with enriched oxygen vacancies stimulated the charge redistribution in their coupling regions,which effectively optimizes the adsorption/desorption of O-related intermediates in ORR/OER.Benefiting from the Ni/MnO heterostructure moieties and the unique two-dimensional/one-dimensional(2D/1D)superstructure of carbon support with abundantly dispersive active species,the resultant Ni/MnO@N-C NS/NFs deliver robust ORR activity and OER property(an overpotential of 306 mV to obtain 10 mA·cm^(-2))with a smaller potential gap(ΔE=0.77 V)in alkaline electrolyte.More significantly,practical zinc-air battery building with Ni/MnO@N-C NS/NFs delivers a higher open circuit voltage,excellent output power density,and prominent durability with stable charging and discharging cycle life.The present work demonstrates a crucial understanding of building advanced heterostructure electrocatalysts with enriched oxygen vacancies for metal-air batteries application.展开更多
文摘近年来,过渡金属氧化物已被认为是最有希望代替贵金属作为锂氧(Li-O2)电池阴极催化剂的材料。本文研究了一种由静电纺纤维煅烧后自发形成的MnO纳米颗粒作为Li-O2电池的高效催化剂。物性表征的结果显示成功合成了平均粒径为61.82 nm的MnO纳米颗粒,为立方晶系结构,作为Li-O2电池阴极在500次循环中表现出优异的循环稳定性,首次充电过电位为0.46 V,在500 mA·g−1的高电流密度下实现了1000 h的稳定循环,优于大多数已报道的用于Li-O2电池的MnOx催化剂。In recent years, transition metal oxides have been considered the most promising materials to replace precious metals as cathode catalysts for lithium-oxygen batteries. This study investigates MnO nanoparticles that spontaneously form after calcining electrospun fibers as an efficient catalyst for lithium-oxygen (Li-O2) batteries. Physical characterization shows that MnO nanoparticles with an average particle size of 61.82 nm and a cubic crystal structure were successfully synthesized. They exhibit excellent cycling stability as a cathode in Li-O2 batteries, enduring over 500 cycles with an initial overpotential of 0.46 V. Concurrent, they also achieve stable cycling for 1000 hours at a high current density of 500 mA·g−1, outperforming most reported catalysts such as MnOx for Li-O2 batteries.
文摘The application of lithium metal anodes is hindered by low Coulombic efficiency(CE),serious lithium dendrites and volume expansion.An MnO/Polypropylene(PP)composite separator was developed to regulate lithium metal deposition behaviors through in situ forming stable artificial solid electrolyte interface(SEI)passivating layers.The concentration of MnO in the cells can be maintained at a constant based on quite low solubility of MnO in the liquid electrolyte,and the dissolved MnO can be reduced to produce Li_(2)O and Mn metal nanoparticles,which can not only function as nucleating seeds of lithium metal deposits but also repair the broken SEI layer.Dendritic-free Li deposits can be obtained by simple separator coating.It can also improve the electrochemical performance of lithium metal batteries.And it is benefit for applications of Li metal anodes.
基金supported by the National Natural Science Foundation of China(No.22302096)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Nos.23KJB150039 and 24KJB150026)+1 种基金Natural Science Foundation of Zhejiang Province(No.LQ24E040002)the Natural Science Foundation of Huzhou City(No.2023YZ18).
文摘Rational developing high-performance and economically efficient dual-functional oxygen electrocatalysts to drive the lumberly reactivity rates of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)in Zn-air batteries is highly attractive,yet remains conceptually challenging.Herein,Ni/MnO heterostructure nanosheets and nanoparticles firmly anchored onto the N-doped carbon nanofibers(noted as Ni/MnO@N-C NS/NFs)for efficient bifunctional ORR/OER electrocatalysis are designed and realized through a facile electrospinning-pyrolysis-etching strategy.The epitaxial in situ grown Ni/MnO with enriched oxygen vacancies stimulated the charge redistribution in their coupling regions,which effectively optimizes the adsorption/desorption of O-related intermediates in ORR/OER.Benefiting from the Ni/MnO heterostructure moieties and the unique two-dimensional/one-dimensional(2D/1D)superstructure of carbon support with abundantly dispersive active species,the resultant Ni/MnO@N-C NS/NFs deliver robust ORR activity and OER property(an overpotential of 306 mV to obtain 10 mA·cm^(-2))with a smaller potential gap(ΔE=0.77 V)in alkaline electrolyte.More significantly,practical zinc-air battery building with Ni/MnO@N-C NS/NFs delivers a higher open circuit voltage,excellent output power density,and prominent durability with stable charging and discharging cycle life.The present work demonstrates a crucial understanding of building advanced heterostructure electrocatalysts with enriched oxygen vacancies for metal-air batteries application.
