近年来,过渡金属硫化物已成为锂离子电池理想的负极材料之一。其中,MoS_2具有的独特二维层状结构使得其能够让Li+在电化学反应中可逆地嵌入和脱出,且拥有较高的理论储锂容量(670 m A·h/g)而受到广泛关注。但MoS_2作为典型的半导体...近年来,过渡金属硫化物已成为锂离子电池理想的负极材料之一。其中,MoS_2具有的独特二维层状结构使得其能够让Li+在电化学反应中可逆地嵌入和脱出,且拥有较高的理论储锂容量(670 m A·h/g)而受到广泛关注。但MoS_2作为典型的半导体材料,电导率低下且在锂离子嵌入-脱出的过程中会发生较大程度的体积收缩膨胀,所以具有较差的倍率性能和循环性能,限制了其商业化的使用。很多研究通过优化MoS_2结构或与其它导电材料复合来克服上述缺陷。Co_9S_8具有较高的电导率,但由于其迟缓的离子传输动力学表现出低的首次库仑效率及较差的循环稳定性,基于此,将MoS_2与Co_9S_8结合利用二者协同效应来提高复合材料的电化学性能。本文采用溶剂热与气相沉积法制备得MoS_2@Co_9S_8蛋黄结构复合材料电极。MoS_2与Co_9S_8均匀分布于整个蛋黄壳结构,这有利于电子和锂离子的快速传输,从而有效地提升了电极的循环性能和倍率性能。其次,蛋黄壳的空穴有效缓解了在充放电过程中的体积膨胀,及其活性位点有效缩短了离子和电子的传输距离,提高了电极反应动力学并获得高比容量。MoS_2@Co_9S_8蛋黄壳复合物的循环性能与倍率性能在同等条件下均高于Co_9S_8和MoS_2,在电流密度为0.2 A/g下循环500圈后,放电容量仍能维持在631.5 m A·h/g。展开更多
Ba2Co9O14(BCO)是一种新型的电子-氧离子混合导体,在氧离子导体的固体氧化物燃料电池(SOFC)中,其作为阴极材料的应用可能性已经得到证实,本工作探索BCO在质子导体SOFC中的应用可能性。采用固相反应法制备BCO粉体,研究BCO与质子导体电解...Ba2Co9O14(BCO)是一种新型的电子-氧离子混合导体,在氧离子导体的固体氧化物燃料电池(SOFC)中,其作为阴极材料的应用可能性已经得到证实,本工作探索BCO在质子导体SOFC中的应用可能性。采用固相反应法制备BCO粉体,研究BCO与质子导体电解质BZCY(Ba Zr0.1Ce0.7Y0.2O3-δ)之间的化学相容性,分析BCO-BZCY复合阴极在BZCY电解质上的电化学性能。当复合阴极中BCO的质量含量为70%时,阴极性能最佳,界面阻抗活化能为1.26 e V。以BCO-BZCY为阴极,Ni-BZCY为阳极,BZCY为电解质的阳极支撑型单电池,700℃时,单电池的极化阻抗为0.15Ω·cm2,最大功率密度为400 m W·cm-2。展开更多
Metal-organic framework(MOF)derived hybrid materials have been developed as an efficient non-noblemetal electrocatalysts for clean energy conversion systems.In this work,a Co-based MOF containing nitrogen and oxygen h...Metal-organic framework(MOF)derived hybrid materials have been developed as an efficient non-noblemetal electrocatalysts for clean energy conversion systems.In this work,a Co-based MOF containing nitrogen and oxygen heteroatoms(Co-NOMOF)mixed with the thiomolybdate[Mo3S(13)]^2- nanoclusters was used to prepare the N,S,O-doped carbon encapsulating Co9S8 and MoS2(Co9S8/MoS2@NSOC)nanocomposite by one-step pyrolysis.The Co9S8/MoS2@NSOC nanocomposite exhibited remarkable catalytic performance for hydrogen evolution reaction(HER)with overpotential of 194 and 233 mV in 1 M KOH and 0.5 M H2SO4 solution under 10 mA cm^-2,respectively,which was ascribed to the multiheteroatom-doped hierarchical porous carbon matrix and the synergistic effect of intrinsic activity of Co9S8 and MoS2.This work provides new opportunity for developing highly efficient non-precious metal electrochemical catalysts.展开更多
过渡金属硫化物因其制备简单、导电性好以及具有丰富的氧化还原性质被广泛用作电催化剂。在导电基底上原位生长复合材料被认为可有效提高催化剂的电催化性能。基于此,利用简单、可控的电沉积法,以泡沫铜作为导电基底,以硝酸铜和硝酸钴...过渡金属硫化物因其制备简单、导电性好以及具有丰富的氧化还原性质被广泛用作电催化剂。在导电基底上原位生长复合材料被认为可有效提高催化剂的电催化性能。基于此,利用简单、可控的电沉积法,以泡沫铜作为导电基底,以硝酸铜和硝酸钴作为铜源和钴源原位制备了Co9S8-Cu S纳米片阵列。在三电极体系中,将Co9S8-Cu S纳米片阵列作为阳极在1 mol/L KOH溶液中得到了优异的电催化析氧性能,Co9S8-Cu S纳米片阵列获取50 m A/cm2电流密度所需的过电位仅为370 m V,其Tafel斜率低至108 m V/dec,其优异的电催化析氧性能归因于较大的催化活性面积以及复合材料中Co9S8与Cu S之间的协同作用。展开更多
Several challenging issues,such as the poor conductivity of sulfur,shuttle effects,large volume change of cathode,and the dendritic lithium in anode,have led to the low utilization of sulfur and hampered the commercia...Several challenging issues,such as the poor conductivity of sulfur,shuttle effects,large volume change of cathode,and the dendritic lithium in anode,have led to the low utilization of sulfur and hampered the commercialization of lithium–sulfur batteries.In this study,a novel three-dimensionally interconnected network structure comprising Co9 S8 and multiwalled carbon nanotubes(MWCNTs)was synthesized by a solvothermal route and used as the sulfur host.The assembled batteries delivered a specific capacity of1154 m Ah g-1 at 0.1 C,and the retention was 64%after 400 cycles at 0.5 C.The polar and catalytic Co9 S8 nanoparticles have a strong adsorbent effect for polysulfide,which can effectively reduce the shuttling effect.Meanwhile,the three-dimensionally interconnected CNT networks improve the overall conductivity and increase the contact with the electrolyte,thus enhancing the transport of electrons and Li ions.Polysulfide adsorption is greatly increased with the synergistic effect of polar Co9 S8 and MWCNTs in the three-dimensionally interconnected composites,which contributes to their promising performance for the lithium–sulfur batteries.展开更多
Lithium sulfur(Li-S)batteries with high specific capacity and energy density can bring enormous opportunities for the nextgeneration energy storage systems.However,the severe dissolution and shuttle effect of lithium ...Lithium sulfur(Li-S)batteries with high specific capacity and energy density can bring enormous opportunities for the nextgeneration energy storage systems.However,the severe dissolution and shuttle effect of lithium polysulfides(LiPSs)is still the key issue that seriously impedes the development of practical Li-S batteries.Here,polar Co9S8 inlaid carbon nanoboxes(Co9S8@C NBs)have been investigated as cathode host for high-performance Li-S batteries.In this integrated structure,Co9S8 nanocrystals not only provide strong chemisorptive capability for polar LiPSs,but also act as a catalyst to accelerate polysulfide redox reactions;while carbon nanobox with large inner space can offer enough space to relieve the volume expansion and physically confine LiPSs’dissolution.As a result,the S/Co9S8@C NBs cathode exhibits high specific capacity at 1C and the capacity retention was^83%after 400 cycles,corresponding to an average decay rate of only^0.043%per cycle.展开更多
In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,w...In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,which is able to act as a self-supported electrode for asymmetric supercapacitors(ASCs).Combining the defect-rich active materials with highly conductive skeletons,the hybrid electrode N-GNTs@sd-Co9S8/Ni3S2NFs show ultrahigh specific capacity of^304 mA hg^-1 and prominent rate capability(capacity retention ratio of^85%even at 100 Ag^-1),and deliver a long cycling lifespan of^1.9%capacitance loss after 10000 cycles.In addition,an ASC was constructed using the as-synthesized composite electrode as the positive electrode and active carbon(AC)as the negative electrode.The fabricated device shows a high energy density of^45.1 Wh kg^-1 at^3.4 kW kg^-1 and superior cycling stability.This work substantiates a smart strategy to fabricate novel composite electrode materials for next-generation supercapacitors by incorporating riched deficiencies into nanostructures.展开更多
文摘近年来,过渡金属硫化物已成为锂离子电池理想的负极材料之一。其中,MoS_2具有的独特二维层状结构使得其能够让Li+在电化学反应中可逆地嵌入和脱出,且拥有较高的理论储锂容量(670 m A·h/g)而受到广泛关注。但MoS_2作为典型的半导体材料,电导率低下且在锂离子嵌入-脱出的过程中会发生较大程度的体积收缩膨胀,所以具有较差的倍率性能和循环性能,限制了其商业化的使用。很多研究通过优化MoS_2结构或与其它导电材料复合来克服上述缺陷。Co_9S_8具有较高的电导率,但由于其迟缓的离子传输动力学表现出低的首次库仑效率及较差的循环稳定性,基于此,将MoS_2与Co_9S_8结合利用二者协同效应来提高复合材料的电化学性能。本文采用溶剂热与气相沉积法制备得MoS_2@Co_9S_8蛋黄结构复合材料电极。MoS_2与Co_9S_8均匀分布于整个蛋黄壳结构,这有利于电子和锂离子的快速传输,从而有效地提升了电极的循环性能和倍率性能。其次,蛋黄壳的空穴有效缓解了在充放电过程中的体积膨胀,及其活性位点有效缩短了离子和电子的传输距离,提高了电极反应动力学并获得高比容量。MoS_2@Co_9S_8蛋黄壳复合物的循环性能与倍率性能在同等条件下均高于Co_9S_8和MoS_2,在电流密度为0.2 A/g下循环500圈后,放电容量仍能维持在631.5 m A·h/g。
文摘Ba2Co9O14(BCO)是一种新型的电子-氧离子混合导体,在氧离子导体的固体氧化物燃料电池(SOFC)中,其作为阴极材料的应用可能性已经得到证实,本工作探索BCO在质子导体SOFC中的应用可能性。采用固相反应法制备BCO粉体,研究BCO与质子导体电解质BZCY(Ba Zr0.1Ce0.7Y0.2O3-δ)之间的化学相容性,分析BCO-BZCY复合阴极在BZCY电解质上的电化学性能。当复合阴极中BCO的质量含量为70%时,阴极性能最佳,界面阻抗活化能为1.26 e V。以BCO-BZCY为阴极,Ni-BZCY为阳极,BZCY为电解质的阳极支撑型单电池,700℃时,单电池的极化阻抗为0.15Ω·cm2,最大功率密度为400 m W·cm-2。
基金supported by the National Science Fund for Distinguished Young Scholars (No. 21825106)National Natural Science Foundation of China (No. 21671175)+2 种基金Program for Science & Technology Innovation Talents in Universities of Henan Province (No. 164100510005)Key Scientific Research Project Plan in Colleges and Universities of Henan Province (No. 16A150045)Program for Innovative Research Team (in Science and Technology) in Universities of Henan Province (No. 19IRTSTHN022).
文摘Metal-organic framework(MOF)derived hybrid materials have been developed as an efficient non-noblemetal electrocatalysts for clean energy conversion systems.In this work,a Co-based MOF containing nitrogen and oxygen heteroatoms(Co-NOMOF)mixed with the thiomolybdate[Mo3S(13)]^2- nanoclusters was used to prepare the N,S,O-doped carbon encapsulating Co9S8 and MoS2(Co9S8/MoS2@NSOC)nanocomposite by one-step pyrolysis.The Co9S8/MoS2@NSOC nanocomposite exhibited remarkable catalytic performance for hydrogen evolution reaction(HER)with overpotential of 194 and 233 mV in 1 M KOH and 0.5 M H2SO4 solution under 10 mA cm^-2,respectively,which was ascribed to the multiheteroatom-doped hierarchical porous carbon matrix and the synergistic effect of intrinsic activity of Co9S8 and MoS2.This work provides new opportunity for developing highly efficient non-precious metal electrochemical catalysts.
文摘过渡金属硫化物因其制备简单、导电性好以及具有丰富的氧化还原性质被广泛用作电催化剂。在导电基底上原位生长复合材料被认为可有效提高催化剂的电催化性能。基于此,利用简单、可控的电沉积法,以泡沫铜作为导电基底,以硝酸铜和硝酸钴作为铜源和钴源原位制备了Co9S8-Cu S纳米片阵列。在三电极体系中,将Co9S8-Cu S纳米片阵列作为阳极在1 mol/L KOH溶液中得到了优异的电催化析氧性能,Co9S8-Cu S纳米片阵列获取50 m A/cm2电流密度所需的过电位仅为370 m V,其Tafel斜率低至108 m V/dec,其优异的电催化析氧性能归因于较大的催化活性面积以及复合材料中Co9S8与Cu S之间的协同作用。
基金National Natural Science Foundation of China(No.51974209)the Natural Science Foundation of Hubei Province of China(Nos.2013CFA021,2017CFB401,2018CFA022)。
文摘Several challenging issues,such as the poor conductivity of sulfur,shuttle effects,large volume change of cathode,and the dendritic lithium in anode,have led to the low utilization of sulfur and hampered the commercialization of lithium–sulfur batteries.In this study,a novel three-dimensionally interconnected network structure comprising Co9 S8 and multiwalled carbon nanotubes(MWCNTs)was synthesized by a solvothermal route and used as the sulfur host.The assembled batteries delivered a specific capacity of1154 m Ah g-1 at 0.1 C,and the retention was 64%after 400 cycles at 0.5 C.The polar and catalytic Co9 S8 nanoparticles have a strong adsorbent effect for polysulfide,which can effectively reduce the shuttling effect.Meanwhile,the three-dimensionally interconnected CNT networks improve the overall conductivity and increase the contact with the electrolyte,thus enhancing the transport of electrons and Li ions.Polysulfide adsorption is greatly increased with the synergistic effect of polar Co9 S8 and MWCNTs in the three-dimensionally interconnected composites,which contributes to their promising performance for the lithium–sulfur batteries.
基金The authors acknowledge the financial support from the National Postdoctoral Program for Innovation Talents(No.BX201700103)China Postdoctoral Science Foundation funded project(No.2018M633664).
文摘Lithium sulfur(Li-S)batteries with high specific capacity and energy density can bring enormous opportunities for the nextgeneration energy storage systems.However,the severe dissolution and shuttle effect of lithium polysulfides(LiPSs)is still the key issue that seriously impedes the development of practical Li-S batteries.Here,polar Co9S8 inlaid carbon nanoboxes(Co9S8@C NBs)have been investigated as cathode host for high-performance Li-S batteries.In this integrated structure,Co9S8 nanocrystals not only provide strong chemisorptive capability for polar LiPSs,but also act as a catalyst to accelerate polysulfide redox reactions;while carbon nanobox with large inner space can offer enough space to relieve the volume expansion and physically confine LiPSs’dissolution.As a result,the S/Co9S8@C NBs cathode exhibits high specific capacity at 1C and the capacity retention was^83%after 400 cycles,corresponding to an average decay rate of only^0.043%per cycle.
基金supported by the National Natural Science Foundation of China(Grant Nos.51672144,51572137,51702181)the Key Research and Development Program of Shandong Province(Grant No.2019GGX102055)+3 种基金the Natural Science Foundation of Shandong Province(Grant Nos.ZR2017BB013,ZR2019BEM042)the Higher Educational Science and Technology Program of Shandong Province(Grant Nos.J17KA014,J18KA001,J18KA033)the Taishan Scholars Program of Shandong Province(Grant No.201511034)the Overseas Taishan Scholars Program。
文摘In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,which is able to act as a self-supported electrode for asymmetric supercapacitors(ASCs).Combining the defect-rich active materials with highly conductive skeletons,the hybrid electrode N-GNTs@sd-Co9S8/Ni3S2NFs show ultrahigh specific capacity of^304 mA hg^-1 and prominent rate capability(capacity retention ratio of^85%even at 100 Ag^-1),and deliver a long cycling lifespan of^1.9%capacitance loss after 10000 cycles.In addition,an ASC was constructed using the as-synthesized composite electrode as the positive electrode and active carbon(AC)as the negative electrode.The fabricated device shows a high energy density of^45.1 Wh kg^-1 at^3.4 kW kg^-1 and superior cycling stability.This work substantiates a smart strategy to fabricate novel composite electrode materials for next-generation supercapacitors by incorporating riched deficiencies into nanostructures.
