The coupling of model batteries and surface-sensitive techniques provides an indispensable platform for interrogating the vital surface/interface processes in battery systems.Here,we report a sandwich-format nanopore-...The coupling of model batteries and surface-sensitive techniques provides an indispensable platform for interrogating the vital surface/interface processes in battery systems.Here,we report a sandwich-format nanopore-array model battery using an ultrathin graphite electrode and an anodized aluminum oxide(AAO)film.The porous framework of AAO regulates the contact pattern of the electrolyte with the graphite electrode from the inner side,while minimizing contamination on the outer surface.This model battery facilitates repetitive charge-discharge processes,where the graphite electrode is reversibly intercalated and deintercalated,and also allows for the in-situ characterizations of ion intercalation in the graphite electrode.The ion distribution profiles indicate that the intercalating Li ions accumulate in both the inner and outer surface regions of graphite,generating a high capacity of~455 mAh·g^(-1)(theory:372 mAh·g^(-1)).The surface enrichment presented herein provides new insights towards the mechanistic understanding of batteries and the rational design strategies.展开更多
As a hybrid energy storage device of lithium-ion batteries and supercapacitors,lithium-ion capacitors have the potential to meet the demanding needs of energy storage equipment with both high power and energy density....As a hybrid energy storage device of lithium-ion batteries and supercapacitors,lithium-ion capacitors have the potential to meet the demanding needs of energy storage equipment with both high power and energy density.In this work,to solve the obstacle to the application of lithium-ion capacitors,that is,the balancing problem of the electrodes kinetic and capacity,two electrodes are designed and adequately matched.For the anode,we introduced in situ carbon-doped and surface-enriched unsaturated sulfur into the graphene conductive network to prepare transition metal sulfides,which enhances the performance with a faster lithium-ion diffusion and dominant pseudocapacitive energy storage.Therefore,the lithium-ion capacitors anode material delivers a remarkable capacity of 810 mAh·g^(−1) after 500 cycles at 1 A·g^(−1).On the other hand,the biomass-derived porous carbon as the cathode also displays a superior capacity of 114.2 mAh·g^(−1) at 0.1 A·g^(−1).Benefitting from the appropriate balance of kinetic and capacity between two electrodes,the lithium-ion capacitors exhibits superior electrochemical performance.The assembled lithium-ion capacitors demonstrate a high energy density of 132.9 Wh·kg^(−1) at the power density of 265 W·kg^(−1),and 50.0 Wh·kg^(−1) even at 26.5 kW·kg^(−1).After 10000 cycles at 1 A·g^(−1),lithium-ion capacitors still demonstrate the high energy density retention of 81.5%.展开更多
基金supported by the National Key Research and Development(R&D)Program of China(No.2021YFA1502800)the National Natural Science Foundation of China(Nos.21825203,22288201,and 91945302)+2 种基金Photon Science Center for Carbon Neutrality,LiaoNing Revitalization Talents Program(No.XLYC1902117)the Dalian National Laboratory for Clean Energy(DNL)Cooperation Fund(No.DNL201907)the Youth Innovation Fund of Dalian Institute of Chemical Physics(No.DICP I202125).
文摘The coupling of model batteries and surface-sensitive techniques provides an indispensable platform for interrogating the vital surface/interface processes in battery systems.Here,we report a sandwich-format nanopore-array model battery using an ultrathin graphite electrode and an anodized aluminum oxide(AAO)film.The porous framework of AAO regulates the contact pattern of the electrolyte with the graphite electrode from the inner side,while minimizing contamination on the outer surface.This model battery facilitates repetitive charge-discharge processes,where the graphite electrode is reversibly intercalated and deintercalated,and also allows for the in-situ characterizations of ion intercalation in the graphite electrode.The ion distribution profiles indicate that the intercalating Li ions accumulate in both the inner and outer surface regions of graphite,generating a high capacity of~455 mAh·g^(-1)(theory:372 mAh·g^(-1)).The surface enrichment presented herein provides new insights towards the mechanistic understanding of batteries and the rational design strategies.
基金supported by the National Natural Science Foundation of China(Grant Nos.51772205 and 51772208)the General Program of Municipal Natural Science Foundation of Tianjin(Grant Nos.17JCYBJC17000 and 17JCYBJC22700).
文摘As a hybrid energy storage device of lithium-ion batteries and supercapacitors,lithium-ion capacitors have the potential to meet the demanding needs of energy storage equipment with both high power and energy density.In this work,to solve the obstacle to the application of lithium-ion capacitors,that is,the balancing problem of the electrodes kinetic and capacity,two electrodes are designed and adequately matched.For the anode,we introduced in situ carbon-doped and surface-enriched unsaturated sulfur into the graphene conductive network to prepare transition metal sulfides,which enhances the performance with a faster lithium-ion diffusion and dominant pseudocapacitive energy storage.Therefore,the lithium-ion capacitors anode material delivers a remarkable capacity of 810 mAh·g^(−1) after 500 cycles at 1 A·g^(−1).On the other hand,the biomass-derived porous carbon as the cathode also displays a superior capacity of 114.2 mAh·g^(−1) at 0.1 A·g^(−1).Benefitting from the appropriate balance of kinetic and capacity between two electrodes,the lithium-ion capacitors exhibits superior electrochemical performance.The assembled lithium-ion capacitors demonstrate a high energy density of 132.9 Wh·kg^(−1) at the power density of 265 W·kg^(−1),and 50.0 Wh·kg^(−1) even at 26.5 kW·kg^(−1).After 10000 cycles at 1 A·g^(−1),lithium-ion capacitors still demonstrate the high energy density retention of 81.5%.
