All-solid-state Li metal battery has been regarded as a promising battery technology due to its high energy density based on the high capacity of lithium metal anode and high safety based on the all solid state electr...All-solid-state Li metal battery has been regarded as a promising battery technology due to its high energy density based on the high capacity of lithium metal anode and high safety based on the all solid state electrolyte without inflammable solvent.However,challenges still exist mainly in the poor contact and unstable interface between electrolyte and electrodes.Herein,we demonstrate an asymmetric design of the composite polymer electrolyte with two different layers to overcome the interface issues at both the cathode and the anode side simultaneously.At the cathode side,the polypropylene carbonate layer has enough viscosity and flexibility to reduce the inter-facial resistance,while at the Li anode side,the polyethylene oxide layer modified with hexagonal boron nitride has high mechanical strength to suppress the Li dendrite growth.Owing to the synergetic effect between different components,the asprepared double layer composite polymer electrolyte demonstrates a large electrochemical window of5.17 V,a high ionic conductivity of 6.1×10~(-4) S/cm,and a transfe rence number of 0.56,featuring excellent ion transport kinetics and good chemical stability.All-solid-state Li metal battery assembled with LiFePO_4 cathode and Li anode delivers a high capacity of 150.9 mAh/g at 25℃ and 0.1 C-rate,showing great potential for practical applications.展开更多
All solid-state lithium metal batteries(ASSLMBs)based on polymer solid electrolyte and lithium metal anode have attracted much attention due to their high energy density and intrinsic safety.However,the low ionic cond...All solid-state lithium metal batteries(ASSLMBs)based on polymer solid electrolyte and lithium metal anode have attracted much attention due to their high energy density and intrinsic safety.However,the low ionic conductivity at room temperature and poor mechanical properties of the solid polymer electrolyte result in increased polarization and poor cycling stability of the Li metal batteries.In order to improve the ionic conductivity at room temperature while maintaining mechanical strength,we combine the conductivity of short chain polyethylene oxide(PEO)and strength of styrene-maleic anhydride copolymer(SMA)to obtain a grafted block copolymer with nanophase separation structure,which has room temperature ionic conductivity up to 1.14×10^(-4)S/cm and tensile strength up to 1.4 MPa.Li||Li symmetric cell can work stably for more than 1500 h under the condition of 0.1 mA/cm^(2).Li||LiFePO_(4)full cells can deliver a high capacity of 151.4 mAh/g at 25℃and 0.2 C/0.2 C charge/discharge conditions,showing 85.6%capacity retention after 400 cycles.Importantly,the all solid state Li||LiFePO_(4)pouch cell shows excellent safety performance under different abuse conditions.These results demonstrate that the nanophase separated,grafted alternate copolymer electrolyte has huge potential for application in Li metal batteries.展开更多
Rechargeable aqueous zinc ion batteries(AZIBs)based on manganese dioxide(MnO_(2))have received much attention for large-scale energy storage applications,however,their energy density is mainly limited by the one-elect...Rechargeable aqueous zinc ion batteries(AZIBs)based on manganese dioxide(MnO_(2))have received much attention for large-scale energy storage applications,however,their energy density is mainly limited by the one-electron reaction of Mn4+/Mn3+redox.Herein,Mo dopedδ-MnO_(2)(Mo-MnO_(2))is prepared and used as a high-performance cathode for AZIBs,which delivers an⇌⇌ultrahigh specific capacity of 652 mAh·g^(−1)at 0.2 A·g^(−1)based on the two-step two-electron redox reaction of Mn^(4+)Mn^(3+)Mn^(2+).Ex-situ structural analysis and density functional theory calculation reveal that the Mo^(5+)dopant plays an important role in enhancing the electronic conductivity of Mo-MnO_(2)and promoting Jahn–Teller distortion of octahedral[MnO_(6)]in ZnMn_(2)O_(4),which facilitates the second step redox reaction of Mn^(3+)/Mn_(2+).This work provides a novel cathode materials design with multi-electron redox chemistry to achieve high energy density in AZIBs.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2016YFB0700604 and 2018YFB1105700)the Natural Science Foundation of Beijing(Nos.2192018,2192037)+1 种基金Beijing University of Chemical Technology(Start-up Grant No.buctrc201901)National Natural Science Foundation of China(Nos.21673008,21774090)。
文摘All-solid-state Li metal battery has been regarded as a promising battery technology due to its high energy density based on the high capacity of lithium metal anode and high safety based on the all solid state electrolyte without inflammable solvent.However,challenges still exist mainly in the poor contact and unstable interface between electrolyte and electrodes.Herein,we demonstrate an asymmetric design of the composite polymer electrolyte with two different layers to overcome the interface issues at both the cathode and the anode side simultaneously.At the cathode side,the polypropylene carbonate layer has enough viscosity and flexibility to reduce the inter-facial resistance,while at the Li anode side,the polyethylene oxide layer modified with hexagonal boron nitride has high mechanical strength to suppress the Li dendrite growth.Owing to the synergetic effect between different components,the asprepared double layer composite polymer electrolyte demonstrates a large electrochemical window of5.17 V,a high ionic conductivity of 6.1×10~(-4) S/cm,and a transfe rence number of 0.56,featuring excellent ion transport kinetics and good chemical stability.All-solid-state Li metal battery assembled with LiFePO_4 cathode and Li anode delivers a high capacity of 150.9 mAh/g at 25℃ and 0.1 C-rate,showing great potential for practical applications.
基金financially supported by the National Natural Science Foundation of China(Nos.21771018,21875004,22108149)Beijing University of Chemical Technology(No.buctrC_(2)01901)+1 种基金Beijing Municipal Natural Science Foundation-Xiaomi Innovation Joint Fund(No.L223011)supported by the program“Research on key technologies of solid-state batteries-research and development of organic-inorganic composite solid-state electrolytes”from China Three Gorges Corporation(No.202103036)。
文摘All solid-state lithium metal batteries(ASSLMBs)based on polymer solid electrolyte and lithium metal anode have attracted much attention due to their high energy density and intrinsic safety.However,the low ionic conductivity at room temperature and poor mechanical properties of the solid polymer electrolyte result in increased polarization and poor cycling stability of the Li metal batteries.In order to improve the ionic conductivity at room temperature while maintaining mechanical strength,we combine the conductivity of short chain polyethylene oxide(PEO)and strength of styrene-maleic anhydride copolymer(SMA)to obtain a grafted block copolymer with nanophase separation structure,which has room temperature ionic conductivity up to 1.14×10^(-4)S/cm and tensile strength up to 1.4 MPa.Li||Li symmetric cell can work stably for more than 1500 h under the condition of 0.1 mA/cm^(2).Li||LiFePO_(4)full cells can deliver a high capacity of 151.4 mAh/g at 25℃and 0.2 C/0.2 C charge/discharge conditions,showing 85.6%capacity retention after 400 cycles.Importantly,the all solid state Li||LiFePO_(4)pouch cell shows excellent safety performance under different abuse conditions.These results demonstrate that the nanophase separated,grafted alternate copolymer electrolyte has huge potential for application in Li metal batteries.
基金supported by the National Natural Science Foundation of China(Nos.21935001 and 22101015)the National Key Research and Development Program of China(No.2018YFA0702002)the Program for Changjiang Scholars and Innovation Research Team in the University(No.IRT1205).
文摘Rechargeable aqueous zinc ion batteries(AZIBs)based on manganese dioxide(MnO_(2))have received much attention for large-scale energy storage applications,however,their energy density is mainly limited by the one-electron reaction of Mn4+/Mn3+redox.Herein,Mo dopedδ-MnO_(2)(Mo-MnO_(2))is prepared and used as a high-performance cathode for AZIBs,which delivers an⇌⇌ultrahigh specific capacity of 652 mAh·g^(−1)at 0.2 A·g^(−1)based on the two-step two-electron redox reaction of Mn^(4+)Mn^(3+)Mn^(2+).Ex-situ structural analysis and density functional theory calculation reveal that the Mo^(5+)dopant plays an important role in enhancing the electronic conductivity of Mo-MnO_(2)and promoting Jahn–Teller distortion of octahedral[MnO_(6)]in ZnMn_(2)O_(4),which facilitates the second step redox reaction of Mn^(3+)/Mn_(2+).This work provides a novel cathode materials design with multi-electron redox chemistry to achieve high energy density in AZIBs.
