Boron-doped Ketjenblack is attempted as cathode catalyst for non-aqueous rechargeable Li–O2 batteries. The boron-doped Ketjenblack delivers an extremely high discharge capacity of 7193 m Ah/g at a current density of ...Boron-doped Ketjenblack is attempted as cathode catalyst for non-aqueous rechargeable Li–O2 batteries. The boron-doped Ketjenblack delivers an extremely high discharge capacity of 7193 m Ah/g at a current density of 0.1 m A/cm2, and the capacity is about 2.3 times as that of the pristine KB. When the batteries are cycled with different restricted capacity, the boron-doped Ketjenblack based cathodes exhibits higher discharge platform and longer cycle life than Ketjenblack based cathodes. Additionally, the boron-doped Ketjenblack also shows a superior electrocatalytic activity for oxygen reduction in 0.1 mol/L KOH aqueous solution. The improvement in catalytic activity results from the defects and activation sites introduced by boron doping.展开更多
Li–O2 batteries have attracted significant interest in the past decade owing to their superior high specific energy density in contrast to conventional lithium ion batteries.An 8.7-Ah Li–O2 pouch cell with768.5 Wh k...Li–O2 batteries have attracted significant interest in the past decade owing to their superior high specific energy density in contrast to conventional lithium ion batteries.An 8.7-Ah Li–O2 pouch cell with768.5 Wh kg^-1 was fabricated and characterized in this investigation and the factors that influenced the electrochemical performance of the Li–O2 pouch cell were studied.In contrast to coin/Swagelok-type Li–O2 cells,it was demonstrated that the high-loading air electrode,pulverization of the Li anode,and the large-scale inhomogeneity of the large pouch cell are the major reasons for the failure of Li–O2 batteries with Ah capacities.In addition,safety tests of large Li–O2 pouch cells were conducted for the first time,including nail penetration,crushing,and thermal stability.It was indicated that a self-limiting mechanism is a key safety feature of these batteries,even when shorted.In this study,Li–O2 batteries were investigated in a new size and capacity-scale,which may provide useful insight into the development of practical pouch-type Li–O2 batteries.展开更多
The conventional Li–O2 battery(LOB)has hardly been considered as a next-generation flexible electronics thus far,since it is bulk,inflexible and limited by the absence of an adjustable cell configuration.Here,we pres...The conventional Li–O2 battery(LOB)has hardly been considered as a next-generation flexible electronics thus far,since it is bulk,inflexible and limited by the absence of an adjustable cell configuration.Here,we present a flexible Li–O2 cell using N-doped carbon nanocages grown onto the carbon textiles(NCNs/CTs)as a self-standing and binder-free O2 electrode.The highly flexible NCNs/CTs exhibits an excellent mechanic durability,a promising catalytic activity towards the ORR and OER,a considerable cyclability of more than 70 cycles with an overpotential of 0.36 V on the 1 stcycle at a constant current density of 0.2 m A/cm2,a good rate capability,a superior reversibility with formation and decomposition of desired Li2 O2,and a highly electrochemical stability even under stringent bending and twisting conditions.Our work represents a promising progress in the material development and architecture design of O2 electrode for flexible LOBs.展开更多
Li–O_2 batteries have attracted much attention because of their high specific energy. However, safety problem generated mainly from the flammable organic liquid electrolytes have hindered the commercial use of Li–O_...Li–O_2 batteries have attracted much attention because of their high specific energy. However, safety problem generated mainly from the flammable organic liquid electrolytes have hindered the commercial use of Li–O_2 batteries. One of the competitive alternatives is polymer electrolytes due to their flexibility and non-flammable property. Moreover, the hybrid polymer electrolyte with enhanced electrochemical properties would be achieved by incorporating inorganic filler, liquid plasticizer and redox mediator into the polymer. While most researches of the hybrid polymer electrolyte focused on Li-ion batteries, few of them took account into its application in Li–O_2 batteries. In this review, we mainly discuss hybrid polymer electrolytes for Li–O_2 batteries with different composition. The critical issues including conductivity and stability of electrolytes are also discussed in detail. Our review provides some insights of hybrid polymer electrolytes for Li–O_2 batteries and offers necessary guidelines for designing the suitable hybrid polymer electrolyte for Li–O_2 batteries as well.展开更多
Electrocatalysts with high efficiency are crucial for improving the storage capacity and electrochemical stability of lithium–oxygen batteries(LOBs).In this work,through a facile hydrothermal method,cobalt–nitrogen-...Electrocatalysts with high efficiency are crucial for improving the storage capacity and electrochemical stability of lithium–oxygen batteries(LOBs).In this work,through a facile hydrothermal method,cobalt–nitrogen-doped carbon nanocubes(Co–N/C),the calcination products of zeolitic imidazolate framework(ZIF–67)are encapsulated by ultrathin C–MoS_(2) nanosheets to obtain Co–N/C@C–MoS_(2) composites which are used as host materials for the oxygen cathode.The synergistic effect between Co–N_(x) active sites and Mo–N coupling centers effectively promotes the formation and decomposition of Li_(2)O_(2) during repeated discharge and charge process.The mesoporous C–MoS_(2) nanosheets with delicately designed morphology facilitate charge transfer and account for improved reaction kinetics and more importantly,suppressed side reactions between the carbon materials and the electrolyte.The oxygen cathode with the Co–N/C@C–MoS_(2)host shows a high initial discharge specific capacity of 21197 mAh g^(-1)and a long operation life of 332 cycles.Theoretical calculation provides in-depth explanation for the reaction mechanism and offers insights for the rational design of electrocatalysts for LOBs.展开更多
A facile synthesis of Ag nanocrystals encapsulated in nitrogen-doped carbon fiber(NCF)is proposed,based on the simultaneous reaction between pyrrole and Ag^(+)ions in an aqueous solvent followed by a heat treatment.Th...A facile synthesis of Ag nanocrystals encapsulated in nitrogen-doped carbon fiber(NCF)is proposed,based on the simultaneous reaction between pyrrole and Ag^(+)ions in an aqueous solvent followed by a heat treatment.The as-prepared Ag/NCF demonstrated superior catalytic behavior toward ORR and OER.Besides improved cycling stability,a much lower discharge/charge gap of 0.89 V(vs Li/Li^(+))compared with 1.38 V for NCF cathode with a fixed capacity of 500 m Ah g^(-1)was obtained in lithium oxygen batteries.The introduction of Ag crystals into NCF facilitates the oxygen reduction reaction/oxygen evolution reaction kinetics.X-ray diffraction analysis coupled with Raman spectroscopy confirmed that Ag/NCF cathode could reversibly catalyze Li_(2)O_(2)formation and decomposition.The NCF matrix offers a conductive network to realize rapid mass transfer and the encapsulated Ag nanocrystals supplied effective catalytic active sites.The combined action between both contributes to the superior electrocatalytic performance.展开更多
基金supported by the MOST(Grant nos.2013CB934000and 2014DFG71590)Beijing Municipal Program(Grant no.YETP0157)
文摘Boron-doped Ketjenblack is attempted as cathode catalyst for non-aqueous rechargeable Li–O2 batteries. The boron-doped Ketjenblack delivers an extremely high discharge capacity of 7193 m Ah/g at a current density of 0.1 m A/cm2, and the capacity is about 2.3 times as that of the pristine KB. When the batteries are cycled with different restricted capacity, the boron-doped Ketjenblack based cathodes exhibits higher discharge platform and longer cycle life than Ketjenblack based cathodes. Additionally, the boron-doped Ketjenblack also shows a superior electrocatalytic activity for oxygen reduction in 0.1 mol/L KOH aqueous solution. The improvement in catalytic activity results from the defects and activation sites introduced by boron doping.
基金supported by the Beijing Municipal Science and Technology Project(Grant No.Z181100004518003)GRINM Youth Foundation Funded Project(Contract No.QGL20190060 or Grant No.69963)。
文摘Li–O2 batteries have attracted significant interest in the past decade owing to their superior high specific energy density in contrast to conventional lithium ion batteries.An 8.7-Ah Li–O2 pouch cell with768.5 Wh kg^-1 was fabricated and characterized in this investigation and the factors that influenced the electrochemical performance of the Li–O2 pouch cell were studied.In contrast to coin/Swagelok-type Li–O2 cells,it was demonstrated that the high-loading air electrode,pulverization of the Li anode,and the large-scale inhomogeneity of the large pouch cell are the major reasons for the failure of Li–O2 batteries with Ah capacities.In addition,safety tests of large Li–O2 pouch cells were conducted for the first time,including nail penetration,crushing,and thermal stability.It was indicated that a self-limiting mechanism is a key safety feature of these batteries,even when shorted.In this study,Li–O2 batteries were investigated in a new size and capacity-scale,which may provide useful insight into the development of practical pouch-type Li–O2 batteries.
基金supported by National Key R&D Program of China(2016YFB0100500)Special fund of key technology research and development projects(20180201097GX)(20180201099GX)(20180201096GX)+5 种基金Jilin Province Science and Technology Department.The R&D Program of power batteries with low temperature and high energy,Science and Technology Bureau of Changchun(19SS013)Key Subject Construction of Physical Chemistry of Northeast Normal UniversityGeneral Financial Grant from the China Postdoctoral Science Foundation(Grant 2016M601363)Fundamental Research Funds for the Central Universities(Grant2412017QD011)Jilin Scientific and Technological Development Program(Grant 20180520143JH)National Natural Science Foundation of China(Grant 21805030)。
文摘The conventional Li–O2 battery(LOB)has hardly been considered as a next-generation flexible electronics thus far,since it is bulk,inflexible and limited by the absence of an adjustable cell configuration.Here,we present a flexible Li–O2 cell using N-doped carbon nanocages grown onto the carbon textiles(NCNs/CTs)as a self-standing and binder-free O2 electrode.The highly flexible NCNs/CTs exhibits an excellent mechanic durability,a promising catalytic activity towards the ORR and OER,a considerable cyclability of more than 70 cycles with an overpotential of 0.36 V on the 1 stcycle at a constant current density of 0.2 m A/cm2,a good rate capability,a superior reversibility with formation and decomposition of desired Li2 O2,and a highly electrochemical stability even under stringent bending and twisting conditions.Our work represents a promising progress in the material development and architecture design of O2 electrode for flexible LOBs.
基金partially supported by National Natural Science Foundation of China(21673116,21633003,51602144)National Key Research and Development Program of China(2016YFB0100203)+2 种基金Natural Science Foundation of Jiangsu Province of China(BK20160068)Fundamental Research Funds for the Central Universities(021314380130)PAPD of Jiangsu Higher Education Institutions
文摘Li–O_2 batteries have attracted much attention because of their high specific energy. However, safety problem generated mainly from the flammable organic liquid electrolytes have hindered the commercial use of Li–O_2 batteries. One of the competitive alternatives is polymer electrolytes due to their flexibility and non-flammable property. Moreover, the hybrid polymer electrolyte with enhanced electrochemical properties would be achieved by incorporating inorganic filler, liquid plasticizer and redox mediator into the polymer. While most researches of the hybrid polymer electrolyte focused on Li-ion batteries, few of them took account into its application in Li–O_2 batteries. In this review, we mainly discuss hybrid polymer electrolytes for Li–O_2 batteries with different composition. The critical issues including conductivity and stability of electrolytes are also discussed in detail. Our review provides some insights of hybrid polymer electrolytes for Li–O_2 batteries and offers necessary guidelines for designing the suitable hybrid polymer electrolyte for Li–O_2 batteries as well.
基金supported by the National Natural Science Foundation of China(52006208)the National Innovative Talents Program(GG2090007001)+2 种基金Chinese Academy of Sciences Program(KJ2090130001)USTC Startup Program(KY2090000044)USTC Tang Scholar(KY2090000065)。
基金Postdoctoral Science Foundation(Grant No.172731)Key R&D and Transformation Projects in Qinghai Province(No.2021-HZ-808)the Talents Project of Beijing Municipal Committee Organization Deparment(No.2018000021223ZK21)。
文摘Electrocatalysts with high efficiency are crucial for improving the storage capacity and electrochemical stability of lithium–oxygen batteries(LOBs).In this work,through a facile hydrothermal method,cobalt–nitrogen-doped carbon nanocubes(Co–N/C),the calcination products of zeolitic imidazolate framework(ZIF–67)are encapsulated by ultrathin C–MoS_(2) nanosheets to obtain Co–N/C@C–MoS_(2) composites which are used as host materials for the oxygen cathode.The synergistic effect between Co–N_(x) active sites and Mo–N coupling centers effectively promotes the formation and decomposition of Li_(2)O_(2) during repeated discharge and charge process.The mesoporous C–MoS_(2) nanosheets with delicately designed morphology facilitate charge transfer and account for improved reaction kinetics and more importantly,suppressed side reactions between the carbon materials and the electrolyte.The oxygen cathode with the Co–N/C@C–MoS_(2)host shows a high initial discharge specific capacity of 21197 mAh g^(-1)and a long operation life of 332 cycles.Theoretical calculation provides in-depth explanation for the reaction mechanism and offers insights for the rational design of electrocatalysts for LOBs.
基金financial support from an Australian Research Council(ARC)Discovery Project(DP180101453)The Distinguished Young Scientists Program of the National Natural Science Foundation of China(No.51425301)+1 种基金the National Natural Science Foundation of China(No.52002171,No.52002050)the Natural Science Foundation of Jiangsu Province(No.BK20200696,No.BK20200768,No.20KJB430019)are greatly appreciated
文摘A facile synthesis of Ag nanocrystals encapsulated in nitrogen-doped carbon fiber(NCF)is proposed,based on the simultaneous reaction between pyrrole and Ag^(+)ions in an aqueous solvent followed by a heat treatment.The as-prepared Ag/NCF demonstrated superior catalytic behavior toward ORR and OER.Besides improved cycling stability,a much lower discharge/charge gap of 0.89 V(vs Li/Li^(+))compared with 1.38 V for NCF cathode with a fixed capacity of 500 m Ah g^(-1)was obtained in lithium oxygen batteries.The introduction of Ag crystals into NCF facilitates the oxygen reduction reaction/oxygen evolution reaction kinetics.X-ray diffraction analysis coupled with Raman spectroscopy confirmed that Ag/NCF cathode could reversibly catalyze Li_(2)O_(2)formation and decomposition.The NCF matrix offers a conductive network to realize rapid mass transfer and the encapsulated Ag nanocrystals supplied effective catalytic active sites.The combined action between both contributes to the superior electrocatalytic performance.
