Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the...Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the cathode side,which strictly requires the development of high voltage,high capacity,and earth-abundant cathode material.Ni-Fe-Mn ternary layered oxide has been recognized as one of the most promising standard type of cathodes.However,the composition and phase structure on high-voltage characteristics have not been well investigated.Herein,selecting the typically high-voltage cathode of P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)as a parent material,we fabricate ten Ni-Fe-Mn ternary layered oxides through replacing the Ni,Mn,or both Ni and Mn by Fe.The thermodynamically stable phase diagram for those materials is presented.The electrochemical properties for all the samples are investigated in detail.Three potential Ni-Fe-Mn ternary layered oxides are picked up considering the energy density,cycle stability,kinetics,cost price,and working voltage,which demonstrate great potential for surpassing the performance of lithium iron phosphate.The related electrochemical reaction and fading mechanism are well revealed.This work provides some new foundational Ni-Fe-Mn ternary layered materials for high-voltage sodium-ion batteries.展开更多
Modern engineering has long been in demand for high-performance additive manufactured materials for harsh working conditions.The idea of high entropy alloy(HEA),medium entropy alloy(MEA),and multi-principal-element al...Modern engineering has long been in demand for high-performance additive manufactured materials for harsh working conditions.The idea of high entropy alloy(HEA),medium entropy alloy(MEA),and multi-principal-element alloy(MPEA)provides a new way for alloy design.In this work,we develop a Co42 Cr20 Ni30 Ti4 Al4 quinary MEA which exhibits a superiority of mechanical properties over a wide tem-perature ranging from 77 to 873 K via selective laser melting(SLM)and post-heat treatment.The present MEA achieves an excellent ultimate tensile strength(UTS)of 1586 MPa with a total elongation(TE)of 22.7%at 298 K,a UTS of 1944 MPa with a TE of 22.6%at 77 K,and a UTS of 1147 MPa with a TE of 9.1%at 873 K.The excellent mechanical properties stem from the microstructures composed of partially refined grains and heterogeneously precipitated L12 phase due to the concurrence of recrystallization and precipitation.The grain boundary hardening,precipitation hardening,and dislocation hardening con-tribute to the high YS at 298 and 77 K.Interactions of nano-spaced stacking faults(SFs)including SFs networks,Lomer-Cottrell locks(L-C locks),and anti-phase boundaries(APBs)induced by the shearing of L12 phase are responsible for the high strain hardening rate and plasticity at 77 K.Our work provides a new insight for the incorporation of precipitation hardening and additive manufacturing technology,paving the avenue for the development of high-performance structural materials.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.52402215)the Anhui Provincial Natural Science Foundation(2408085QB036)+1 种基金the Natural Science Research Project of Anhui Province Education Department(Grant Nos.2022AH050334,2022AH030046,2023AH051119)the Scientific Research Foundation of Anhui University of Technology for Talent Introduction(DT2200001211)。
文摘Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the cathode side,which strictly requires the development of high voltage,high capacity,and earth-abundant cathode material.Ni-Fe-Mn ternary layered oxide has been recognized as one of the most promising standard type of cathodes.However,the composition and phase structure on high-voltage characteristics have not been well investigated.Herein,selecting the typically high-voltage cathode of P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)as a parent material,we fabricate ten Ni-Fe-Mn ternary layered oxides through replacing the Ni,Mn,or both Ni and Mn by Fe.The thermodynamically stable phase diagram for those materials is presented.The electrochemical properties for all the samples are investigated in detail.Three potential Ni-Fe-Mn ternary layered oxides are picked up considering the energy density,cycle stability,kinetics,cost price,and working voltage,which demonstrate great potential for surpassing the performance of lithium iron phosphate.The related electrochemical reaction and fading mechanism are well revealed.This work provides some new foundational Ni-Fe-Mn ternary layered materials for high-voltage sodium-ion batteries.
基金supported by the National Natural Science Foundation of China(No.52020105013).
文摘Modern engineering has long been in demand for high-performance additive manufactured materials for harsh working conditions.The idea of high entropy alloy(HEA),medium entropy alloy(MEA),and multi-principal-element alloy(MPEA)provides a new way for alloy design.In this work,we develop a Co42 Cr20 Ni30 Ti4 Al4 quinary MEA which exhibits a superiority of mechanical properties over a wide tem-perature ranging from 77 to 873 K via selective laser melting(SLM)and post-heat treatment.The present MEA achieves an excellent ultimate tensile strength(UTS)of 1586 MPa with a total elongation(TE)of 22.7%at 298 K,a UTS of 1944 MPa with a TE of 22.6%at 77 K,and a UTS of 1147 MPa with a TE of 9.1%at 873 K.The excellent mechanical properties stem from the microstructures composed of partially refined grains and heterogeneously precipitated L12 phase due to the concurrence of recrystallization and precipitation.The grain boundary hardening,precipitation hardening,and dislocation hardening con-tribute to the high YS at 298 and 77 K.Interactions of nano-spaced stacking faults(SFs)including SFs networks,Lomer-Cottrell locks(L-C locks),and anti-phase boundaries(APBs)induced by the shearing of L12 phase are responsible for the high strain hardening rate and plasticity at 77 K.Our work provides a new insight for the incorporation of precipitation hardening and additive manufacturing technology,paving the avenue for the development of high-performance structural materials.
