Rechargeable batteries based on solid-state electrolytes are of great interest and importance for the next-generation energy storage due to their high energy output and improved safety.For building the solid-state bat...Rechargeable batteries based on solid-state electrolytes are of great interest and importance for the next-generation energy storage due to their high energy output and improved safety.For building the solid-state batteries,Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)represents a promising candidate as it features high chemical stability against air exposure and a high Na^(+)conductivity.NZSP pellets were usually calcined at a high temperature,and the high volatility of Na and P elements easily led to the formation of impurity phase.In this work,the effects of calcination temperature and stoichiometry on the phase purity and ionic conductivity of the NZSP electrolyte were studied.At an elevated sintering temperature,the NZSP electrolyte showed a high ionic conductivity owing to decreased porosity,and the highest ionic conductivity at 30℃was observed to be 2.75×10^(-5)S·cm^(-1)with an activation energy of 0.41 eV.For the stoichiometry,the introduction of 5 mol%excessive P results in formation of more Na_(3)PO_(4) and glass-like phase at the grain boundary,which caused the blurred grain boundary and reduced grain barrier,and effectively suppressed Na dendrite growth,then accounted for improved cycling performance of a Na‖Na symmetric cell.Our work provided insights on reasonable design and preparation of NZSP electrolyte towards practical realization of solid-state Na-metal batteries.展开更多
The recovery and utilization of carbon dioxide(CO_(2))is the key to achieve the targets of peak carbon dioxide emissions and carbon neutrality.The Na-CO_(2)battery made with cheap alkali metal sodium and greenhouse ga...The recovery and utilization of carbon dioxide(CO_(2))is the key to achieve the targets of peak carbon dioxide emissions and carbon neutrality.The Na-CO_(2)battery made with cheap alkali metal sodium and greenhouse gas CO_(2)is an effective strategy to consume CO_(2)and store clean renewable energy.However,the liquid electrolyte volatilization in the open battery system and inevitable dendrite growth restrict the application of Na-CO_(2)batteries.In this work,magnesium-doped Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)was studied as a solid electrolyte for solid-state Na-CO_(2)batteries.The ionic conductivity of Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)reaches 1.16 mS cm^(−1)at room temperature by replacing Zr ions in Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)with Mg ions,and the structural changes are analyzed by neutron powder diffraction.The composite electrolyte consisting of highly conductive Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)and high processability poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)is utilized for the first time to assemble a solid-state Na-CO_(2)battery.The cell shows a full discharge capacity of 7720 mAh g^(−1)at 200 mA g^(−1).The middle gap voltage is lower than 2 V after 120 cycles at 200 mA g^(−1)and at a cut-off capacity of 500 mAh g^(−1).This work demonstrates a promising strategy to design high-performance solid-state Na-CO_(2)batteries.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51902238 and 52172234)the Fundamental Research Funds for the Central Universities(Nos.2020IVA069,2020IVB043 and 2021IVA020B)
文摘Rechargeable batteries based on solid-state electrolytes are of great interest and importance for the next-generation energy storage due to their high energy output and improved safety.For building the solid-state batteries,Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)represents a promising candidate as it features high chemical stability against air exposure and a high Na^(+)conductivity.NZSP pellets were usually calcined at a high temperature,and the high volatility of Na and P elements easily led to the formation of impurity phase.In this work,the effects of calcination temperature and stoichiometry on the phase purity and ionic conductivity of the NZSP electrolyte were studied.At an elevated sintering temperature,the NZSP electrolyte showed a high ionic conductivity owing to decreased porosity,and the highest ionic conductivity at 30℃was observed to be 2.75×10^(-5)S·cm^(-1)with an activation energy of 0.41 eV.For the stoichiometry,the introduction of 5 mol%excessive P results in formation of more Na_(3)PO_(4) and glass-like phase at the grain boundary,which caused the blurred grain boundary and reduced grain barrier,and effectively suppressed Na dendrite growth,then accounted for improved cycling performance of a Na‖Na symmetric cell.Our work provided insights on reasonable design and preparation of NZSP electrolyte towards practical realization of solid-state Na-metal batteries.
基金supported by Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(Grant No.2022-K15)China University of Mining&Technology(Beijing),Beijing National Laboratory for Condensed Matter Physics,and the National Natural Science Foundation of China(No.51672029 and 51372271)the Spanish Ministry of Science,Innovation to the project MAT2017-84496-R.CAL acknowledges ANPCyT,UNSL for financial support(projects PICT2017-1842,PROICO 2-2016),Argentine.
文摘The recovery and utilization of carbon dioxide(CO_(2))is the key to achieve the targets of peak carbon dioxide emissions and carbon neutrality.The Na-CO_(2)battery made with cheap alkali metal sodium and greenhouse gas CO_(2)is an effective strategy to consume CO_(2)and store clean renewable energy.However,the liquid electrolyte volatilization in the open battery system and inevitable dendrite growth restrict the application of Na-CO_(2)batteries.In this work,magnesium-doped Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)was studied as a solid electrolyte for solid-state Na-CO_(2)batteries.The ionic conductivity of Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)reaches 1.16 mS cm^(−1)at room temperature by replacing Zr ions in Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)with Mg ions,and the structural changes are analyzed by neutron powder diffraction.The composite electrolyte consisting of highly conductive Na_(3.2)Zr_(1.9)Mg_(0.1)Si_(2)PO_(12)and high processability poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)is utilized for the first time to assemble a solid-state Na-CO_(2)battery.The cell shows a full discharge capacity of 7720 mAh g^(−1)at 200 mA g^(−1).The middle gap voltage is lower than 2 V after 120 cycles at 200 mA g^(−1)and at a cut-off capacity of 500 mAh g^(−1).This work demonstrates a promising strategy to design high-performance solid-state Na-CO_(2)batteries.
