Lithium（Li） metal is an ideal anode material for rechargeable Li batteries, due to its high theoretical specific capacity（3860 mAh/g）, low density（0.534 g/cm3）, and low negative electrochemical potential（-3.040...Lithium（Li） metal is an ideal anode material for rechargeable Li batteries, due to its high theoretical specific capacity（3860 mAh/g）, low density（0.534 g/cm3）, and low negative electrochemical potential（-3.040 V vs. standard hydrogen electrode）. In this work, the concentrated electrolytes with dual salts, composed of Li[N（SO2F）2]（Li FSI） and Li[N（SO2CF3）2]（Li TFSI） were studied. In this dual-salt system, the capacity retention can even be maintained at 95.7%after 100 cycles in Li｜Li FePO4 cells. A Li｜Li cell can be cycled at 0.5 mA/cm2 for more than 600 h, and a Li｜Cu cell can be cycled at 0.5 m A/cm2 for more than 200 cycles with a high average Coulombi efficiency of 99%. These results show that the concentrated dual-salt electrolytes exhibit superior electrochemical performance and would be a promising candidate for application in rechargeable Li batteries.展开更多
A new concept of forming solid electrolyte interphases（SEI） in situ in an ionic conducting Li（1.5）Al（0.5）Ge（1.5）（PO4）3-polypropylene（LAGP-PP） based separator during charging and discharging is proposed and...A new concept of forming solid electrolyte interphases（SEI） in situ in an ionic conducting Li（1.5）Al（0.5）Ge（1.5）（PO4）3-polypropylene（LAGP-PP） based separator during charging and discharging is proposed and demonstrated. This unique structure shows a high ionic conductivity, low interface resistance with electrode, and can suppress the growth of lithium dendrite. The features of forming the SEI in situ are investigated by scanning electron microscopy（SEM） and x-ray photoelectron spectroscopy（XPS）. The results confirm that SEI films mainly consist of lithium fluoride and carbonates with various alkyl contents. The cell assembled by using the LAGP-coated separator demonstrates a good cycling performance even at high charging rates, and the lithium dendrites were not observed on the lithium metal electrode. Therefore, the SEI-LAGP-PP separator can be used as a promising flexible solid electrolyte for solid state lithium batteries.展开更多
All-solid-state batteries offer an attractive option for developing safe lithium-ion batteries.Among the various solid-state electrolyte candidates for their applications,sulfide solid electrolytes are the most suitab...All-solid-state batteries offer an attractive option for developing safe lithium-ion batteries.Among the various solid-state electrolyte candidates for their applications,sulfide solid electrolytes are the most suitable owing to their high ionic conductivity and facile processability.However,their performance is extensively lower compared with those of conventional liquid electrolyte-based batteries mainly because of interfacial reactions between the solid electrolytes and high capacity cathodes.Moreover,the kinetic evolution reaction in the composite cathode of all-solid-state lithium batteries has not been actively discussed.Here,electrochemical analyses were performed to investigate the differences between the organic liquid electrolyte-based battery and all-solid-state battery systems.Combined with electrochemical analyses and synchrotron-based in situ and ex situ X-ray analyses,it was confirmed that inhomogeneous reactions were due to physical contact.Loosely contacted and/or isolated active material particles account for the inhomogeneously charged regions,which further intensify the inhomogeneous reactions during extended cycles,thereby increasing the polarization of the system.This study highlighted the benefits of electrochemo-mechanical integrity for securing a smooth conduction pathway and the development of a reliable homogeneous reaction system for the success of solid-state batteries.展开更多
基金Project supported by the National Nature Science Foundation of China(Grant Nos.51222210,51472268,51421002,and 11234013)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA09010300)
文摘Lithium（Li） metal is an ideal anode material for rechargeable Li batteries, due to its high theoretical specific capacity（3860 mAh/g）, low density（0.534 g/cm3）, and low negative electrochemical potential（-3.040 V vs. standard hydrogen electrode）. In this work, the concentrated electrolytes with dual salts, composed of Li[N（SO2F）2]（Li FSI） and Li[N（SO2CF3）2]（Li TFSI） were studied. In this dual-salt system, the capacity retention can even be maintained at 95.7%after 100 cycles in Li｜Li FePO4 cells. A Li｜Li cell can be cycled at 0.5 mA/cm2 for more than 600 h, and a Li｜Cu cell can be cycled at 0.5 m A/cm2 for more than 200 cycles with a high average Coulombi efficiency of 99%. These results show that the concentrated dual-salt electrolytes exhibit superior electrochemical performance and would be a promising candidate for application in rechargeable Li batteries.
基金Project supported by the Beijing Science and Technology ProjectChina(Grant No.Z13111000340000)+1 种基金the National Basic Research Program of China(Grant No.2012CB932900)the National Natural Science Foundation of China(Grant Nos.51325206 and 51421002)
文摘A new concept of forming solid electrolyte interphases（SEI） in situ in an ionic conducting Li（1.5）Al（0.5）Ge（1.5）（PO4）3-polypropylene（LAGP-PP） based separator during charging and discharging is proposed and demonstrated. This unique structure shows a high ionic conductivity, low interface resistance with electrode, and can suppress the growth of lithium dendrite. The features of forming the SEI in situ are investigated by scanning electron microscopy（SEM） and x-ray photoelectron spectroscopy（XPS）. The results confirm that SEI films mainly consist of lithium fluoride and carbonates with various alkyl contents. The cell assembled by using the LAGP-coated separator demonstrates a good cycling performance even at high charging rates, and the lithium dendrites were not observed on the lithium metal electrode. Therefore, the SEI-LAGP-PP separator can be used as a promising flexible solid electrolyte for solid state lithium batteries.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2021M3H4A1A02045953 and No.NRF-2021R1C1C2007797)。
文摘All-solid-state batteries offer an attractive option for developing safe lithium-ion batteries.Among the various solid-state electrolyte candidates for their applications,sulfide solid electrolytes are the most suitable owing to their high ionic conductivity and facile processability.However,their performance is extensively lower compared with those of conventional liquid electrolyte-based batteries mainly because of interfacial reactions between the solid electrolytes and high capacity cathodes.Moreover,the kinetic evolution reaction in the composite cathode of all-solid-state lithium batteries has not been actively discussed.Here,electrochemical analyses were performed to investigate the differences between the organic liquid electrolyte-based battery and all-solid-state battery systems.Combined with electrochemical analyses and synchrotron-based in situ and ex situ X-ray analyses,it was confirmed that inhomogeneous reactions were due to physical contact.Loosely contacted and/or isolated active material particles account for the inhomogeneously charged regions,which further intensify the inhomogeneous reactions during extended cycles,thereby increasing the polarization of the system.This study highlighted the benefits of electrochemo-mechanical integrity for securing a smooth conduction pathway and the development of a reliable homogeneous reaction system for the success of solid-state batteries.
