Nickel(Ni)-rich layered oxides have drawn great attention as cathode for lithium batteries due to their high capacity,high working voltage and competitive cost.Unfortunately,the operation of Ni-rich cathodes suffers f...Nickel(Ni)-rich layered oxides have drawn great attention as cathode for lithium batteries due to their high capacity,high working voltage and competitive cost.Unfortunately,the operation of Ni-rich cathodes suffers from the notorious structural degradation and interfacial side reactions with electrolytes and thus incurs premature failure,especially at high charge cut-off voltages(≥4.4 V).For this,various structural and interphase regulation strategies(such as coating modification,element doping,and electrolyte engineering)are developed to enhance the cycling survivability of Ni-rich cathodes.Among them,electrolyte engineering by changing solvation structure and introducing additives has been considered an efficient method for constructing robust cathode-electrolyte interphases(CEI),inhibiting the formation of harmful species(such as HF and H_(2)O)or restraining the dissolution of transition metal ions.However,there is still an absence of systematic guidelines for selecting and designing competitive electrolyte systems for Ni-rich layered cathodes.In this review,we comprehensively summarize the recent research progress on electrolyte engineering for Ni-rich layered cathodes according to their working mechanisms.Moreover,we propose future perspectives of improving the electrolyte performance,which will provide new insights for designing novel electrolytes toward high-performance Ni-rich layered cathodes.展开更多
Composite solid-state electrolytes have received significant attention due to their combined advantages as inorganic and polymer electrolytes.However,conventional ceramic fillers offer limited ion conductivity enhance...Composite solid-state electrolytes have received significant attention due to their combined advantages as inorganic and polymer electrolytes.However,conventional ceramic fillers offer limited ion conductivity enhancement for composite solid-state electrolytes due to the space-charge layer between the polymer matrix and ceramic phase.In this study,we develop a ferroelectric ceramic ion conductor(LiTaO_(3))as a func-tional filler to simultaneously alleviate the space-charge layer and provide an extra Li+transport pathway.The obtained composite solid-state electrolyte comprising LiTaO_(3)filler and poly(vinylidene difluoride)matrix(P-LTO15)achieves an ionic conductivity of 4.90×10^(−4)S cm−1 and a Li+transference number of 0.45.The polar-ized ferroelectric LiTaO_(3)creates a uniform electric field and promotes homogenous Li plating/stripping,providing the Li symmetrical batteries with an ultrastable cycle life for 4000 h at 0.1 mA cm^(−2)and a low polar-ization overpotential(~50 mV).Furthermore,the solid-state NCM811/P-LTO15/Li full batteries achieve an ultralong cycling performance(1400 cycles)at 1 C and a high discharge capacity of 102.1 mAh g^(−1)at 5 C.This work sheds light on the design of functional ceramic fillers for composite solid-state electrolytes to effec-tively enhance ion conductivity and battery performance.展开更多
The low ionic conductivity of composite solid-state electrolytes due to the lack of free Li-ions and Li dendrite growth induced by the low transference number seriously hinder their application.Herein,we find that the...The low ionic conductivity of composite solid-state electrolytes due to the lack of free Li-ions and Li dendrite growth induced by the low transference number seriously hinder their application.Herein,we find that the giant dielectric ceramic of Li_(0.3)Ti_(0.02)Ni_(0.68O)(LTNO)with ultra-high dielectric constant can greatly promote the dissociation of Li salt to generate abundant movable Li-ions and realize a high room-temperature ionic conductivity(4.09×10^(-4) S cm^(-1))as well as a low activation energy(0.16 eV).The oxygen vacancies on the surface of LTNO can effectively immobi-lize the anions to achieve a high Li transference number(0.61).Furthermore,the enhanced dielectric properties of the composite electrolyte induce homogenous Li plating/stripping to suppress the growth of Li dendrites.As a result,the Li||Li symmetric cells exhibit long lifespan of 2400 h and 1150 h at 0.1 mA cm^(-2) and 0.2 mA cm-2,respec-tively.The Li||LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)solid-state full cells show a high capacity retention of 83%after 430 cycles at 2C.This work highlights the critical role of high dielectric property and oxygen defects of fillers in composite solid-state elec-trolytes,and provides a demonstration for the application of giant dielectric materials in solid-state Li metal batteries.展开更多
基金supported by the National Key Research and Development Program of China(2021YFF0500600)National Natural Science Foundation of China(Nos.U2001220,52203298 and 523B2022)+2 种基金National Science Fund for Distinguished Young Scholars(No.52325206)Shenzhen Technical Plan Project(Nos.RCJC20200714114436091,JCYJ20220530143012027,JCYJ20220818101003008 and JCYJ20220818101003007)Tsinghua Shenzhen International Graduate School-Shenzhen Pengrui Young Faculty Program of Shenzhen Pengrui Foundation(No.SZPR2023006).
文摘Nickel(Ni)-rich layered oxides have drawn great attention as cathode for lithium batteries due to their high capacity,high working voltage and competitive cost.Unfortunately,the operation of Ni-rich cathodes suffers from the notorious structural degradation and interfacial side reactions with electrolytes and thus incurs premature failure,especially at high charge cut-off voltages(≥4.4 V).For this,various structural and interphase regulation strategies(such as coating modification,element doping,and electrolyte engineering)are developed to enhance the cycling survivability of Ni-rich cathodes.Among them,electrolyte engineering by changing solvation structure and introducing additives has been considered an efficient method for constructing robust cathode-electrolyte interphases(CEI),inhibiting the formation of harmful species(such as HF and H_(2)O)or restraining the dissolution of transition metal ions.However,there is still an absence of systematic guidelines for selecting and designing competitive electrolyte systems for Ni-rich layered cathodes.In this review,we comprehensively summarize the recent research progress on electrolyte engineering for Ni-rich layered cathodes according to their working mechanisms.Moreover,we propose future perspectives of improving the electrolyte performance,which will provide new insights for designing novel electrolytes toward high-performance Ni-rich layered cathodes.
基金supported by the National Natural Science Foundation of China(No.52325206,U2001220 and 52203298)Key-Area Research and Development Program of Guangdong Province(No.2020B090919001)+2 种基金Shenzhen.Shenzhen Outstanding Talents Training FundAll-Solid-State Lithium Battery Electrolyte Engineering Research Center(XMHT20200203006)Shenzhen Technical Plan Project(Nos.RCJC20200714114436091,YJ20220530143012027,JCYJ20220818101003007,JCYJ20220818101003008).
文摘Composite solid-state electrolytes have received significant attention due to their combined advantages as inorganic and polymer electrolytes.However,conventional ceramic fillers offer limited ion conductivity enhancement for composite solid-state electrolytes due to the space-charge layer between the polymer matrix and ceramic phase.In this study,we develop a ferroelectric ceramic ion conductor(LiTaO_(3))as a func-tional filler to simultaneously alleviate the space-charge layer and provide an extra Li+transport pathway.The obtained composite solid-state electrolyte comprising LiTaO_(3)filler and poly(vinylidene difluoride)matrix(P-LTO15)achieves an ionic conductivity of 4.90×10^(−4)S cm−1 and a Li+transference number of 0.45.The polar-ized ferroelectric LiTaO_(3)creates a uniform electric field and promotes homogenous Li plating/stripping,providing the Li symmetrical batteries with an ultrastable cycle life for 4000 h at 0.1 mA cm^(−2)and a low polar-ization overpotential(~50 mV).Furthermore,the solid-state NCM811/P-LTO15/Li full batteries achieve an ultralong cycling performance(1400 cycles)at 1 C and a high discharge capacity of 102.1 mAh g^(−1)at 5 C.This work sheds light on the design of functional ceramic fillers for composite solid-state electrolytes to effec-tively enhance ion conductivity and battery performance.
基金supported by National Natural Science Foundation of China(No.U2001220,52203298 and 523B2022)National Science Fund for Distinguished Young Scholars(No.52325206)and Shenzhen Technical Plan Project(RCJC20200714114436091,JCYJ20220530143012027,JCYJ20220818101003008,JCYJ20220818101003007 and WDZC20231126160733001)Tsinghua Shenzhen International Graduate School-Shenzhen Pengrui Young Faculty Program of Shenzhen Pengrui Foundation(No.SZPR2023006).
文摘The low ionic conductivity of composite solid-state electrolytes due to the lack of free Li-ions and Li dendrite growth induced by the low transference number seriously hinder their application.Herein,we find that the giant dielectric ceramic of Li_(0.3)Ti_(0.02)Ni_(0.68O)(LTNO)with ultra-high dielectric constant can greatly promote the dissociation of Li salt to generate abundant movable Li-ions and realize a high room-temperature ionic conductivity(4.09×10^(-4) S cm^(-1))as well as a low activation energy(0.16 eV).The oxygen vacancies on the surface of LTNO can effectively immobi-lize the anions to achieve a high Li transference number(0.61).Furthermore,the enhanced dielectric properties of the composite electrolyte induce homogenous Li plating/stripping to suppress the growth of Li dendrites.As a result,the Li||Li symmetric cells exhibit long lifespan of 2400 h and 1150 h at 0.1 mA cm^(-2) and 0.2 mA cm-2,respec-tively.The Li||LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)solid-state full cells show a high capacity retention of 83%after 430 cycles at 2C.This work highlights the critical role of high dielectric property and oxygen defects of fillers in composite solid-state elec-trolytes,and provides a demonstration for the application of giant dielectric materials in solid-state Li metal batteries.
