Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering th...Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering them incapable of effectively inhibiting the exchange reaction between lithium ions and transition metal ions in the electrolyte.Consequently,nearly all lithium ions within the SEI film are replaced by transition metal ions,resulting in an increase in interphacial impedance and a decrease in stability.Herein,we demonstrate that the SEI film,constructed by fluoroethylene carbonate(FEC)additive rich in crystalline Li F,effectively inhibits the undesired Li^(+)/Co^(2+)ion exchange reaction,thereby suppressing the deposition of cobalt compounds and metallic cobalt.Furthermore,the deposited cobalt compounds exhibit enhanced structural stability and reduced catalytic activity with minimal impact on the interphacial stability of the graphite anode.Our findings reveal the crucial influence of SEI film composition and structure on the deposition and hazards associated with transition metal ions,providing valuable guidance for designing next-generation electrolytes.展开更多
Developing wide-temperature and high-safety lithium-ion batteries(LIBs)presents significant challenges attributed to the absence of suitable solvents possessing broad liquid range and non-flammability properties.γ-Bu...Developing wide-temperature and high-safety lithium-ion batteries(LIBs)presents significant challenges attributed to the absence of suitable solvents possessing broad liquid range and non-flammability properties.γ-Butyrolactone(GBL)has emerged as a promising solvent;however,its incompatibility with graphite anode has hindered its application.This limitation necessitates a comprehensive investigation into the underlying mechanisms and potential solutions.In this study,we achieve a molecular-level understanding of the perplexing interphase formation process by employing in-situ spectroelectrochemical techniques and density function calculations.Our findings reveal that,even at high salt concentrations,GBL consistently occupies the primary Li^(+)solvation sheath,leading to extensive GBL decomposition and the formation of a high-impedance and inorganic-poor solid-electrolyte interphase(SEI)layer.Contrary to manipulating solvation structures,our research demonstrates that the utilization of filmforming additives with higher reduction potential facilitates the pre-establishment of a robust SEI film on the graphite anode.This approach effectively inhibits GBL decomposition and significantly enhances the battery's lifespan.This study provides the first reported intrinsic understanding of the unique GBLgraphite incompatibility and offers valuable insights for the development of wide-temperature and high-safety LIBs.展开更多
Macro-and micro-interface instability of SiO_(x)anode caused by its dramatic volume variation during cycling will result in low Coulombic efficiency and rapid capacity degradation.In this work,an organic-inorganic com...Macro-and micro-interface instability of SiO_(x)anode caused by its dramatic volume variation during cycling will result in low Coulombic efficiency and rapid capacity degradation.In this work,an organic-inorganic composite interfacial layer rich in benzene ring groups,polyisocyanates,and LiF was obtained on SiO_(x)anode by the introduction of 4-fluorophenyl isocyanate(FPI)and fluoroethylene carbonate(FEC)co-additives in electrolyte.The SiO_(x)anode material shows a capacity retention of 69.2%after 100 cycles at a current density of 1 A g^(-1)and rate capacity of 523 m A h g^(-1)at the current density of 3A g^(-1),while the SiO_(x)anode cycling in reference electrolyte has almost no capacity.展开更多
Lithium-ion batteries with polymer electrolytes(PEs)are promising candidates for high safety performance batteries.However,conventional PEs suffer from poor compatibility and high impedance of electrolyte-electrode in...Lithium-ion batteries with polymer electrolytes(PEs)are promising candidates for high safety performance batteries.However,conventional PEs suffer from poor compatibility and high impedance of electrolyte-electrode interfaces.Herein,we present a method of the interfacial modification for PEs to inhibit lithium dendrites based on the solution to the interfacial compatibility.Our strategy is to improve the interfacial properties and inhibit the dendrite generation by coating a modified layer on PEs of the anode side with acetylene black(AB)and MXene.The mixed conductive layer(MCL)can promote the generation of Li3N and LiF with a uniform arrangement of electrons to form a dense solid electrolyte interphase layer and the even lithium-ion deposition for improving the performance and stability of the battery during cycling.After adding the MCL,the discharge capacity of solid lithium-ion batteries(SLIBs)with lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)/organic modified montmorillonite(OMMT)/soybean isolate protein(SPI)/poly(vinylidene fluoride)(PVDF)(LOSP)PE from 74.2 mAh g^(-1)up to 111.1 mAh g^(-1)(AB-LiTFSI/OMMT/SPI/PVDF(AB-LOSP))and 111.6 mAh g^(-1)(AB/MXene-LiTFSI/OMMT/SPI/PVDF(AB/MXene-LOSP)).The polarization voltage dropped by 0.06 and 0.12 V,respectively.This work represents a milestone in the dendrite-free SLIBs with good performances.展开更多
基金supported by the National Natural Science Foundation of China(21972049,21573080)。
文摘Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering them incapable of effectively inhibiting the exchange reaction between lithium ions and transition metal ions in the electrolyte.Consequently,nearly all lithium ions within the SEI film are replaced by transition metal ions,resulting in an increase in interphacial impedance and a decrease in stability.Herein,we demonstrate that the SEI film,constructed by fluoroethylene carbonate(FEC)additive rich in crystalline Li F,effectively inhibits the undesired Li^(+)/Co^(2+)ion exchange reaction,thereby suppressing the deposition of cobalt compounds and metallic cobalt.Furthermore,the deposited cobalt compounds exhibit enhanced structural stability and reduced catalytic activity with minimal impact on the interphacial stability of the graphite anode.Our findings reveal the crucial influence of SEI film composition and structure on the deposition and hazards associated with transition metal ions,providing valuable guidance for designing next-generation electrolytes.
基金financially supported by the National Natural Science Foundation of China(21972049,22272175)the National Key R&D Program of China(2022YFA1504002)+3 种基金the“Scientist Studio Funding”from Tianmu Lake Institute of Advanced Energy Storage Technologies Co.,Ltd.Dalian Supports High-Level Talent Innovation and Entrepreneurship Projects(2021RD14)the Dalian Institute of Chemical Physics(DICP I202213)the 21C Innovation Laboratory,Contemporary Ampere Technology Ltd.by project No.21C-OP-202208。
文摘Developing wide-temperature and high-safety lithium-ion batteries(LIBs)presents significant challenges attributed to the absence of suitable solvents possessing broad liquid range and non-flammability properties.γ-Butyrolactone(GBL)has emerged as a promising solvent;however,its incompatibility with graphite anode has hindered its application.This limitation necessitates a comprehensive investigation into the underlying mechanisms and potential solutions.In this study,we achieve a molecular-level understanding of the perplexing interphase formation process by employing in-situ spectroelectrochemical techniques and density function calculations.Our findings reveal that,even at high salt concentrations,GBL consistently occupies the primary Li^(+)solvation sheath,leading to extensive GBL decomposition and the formation of a high-impedance and inorganic-poor solid-electrolyte interphase(SEI)layer.Contrary to manipulating solvation structures,our research demonstrates that the utilization of filmforming additives with higher reduction potential facilitates the pre-establishment of a robust SEI film on the graphite anode.This approach effectively inhibits GBL decomposition and significantly enhances the battery's lifespan.This study provides the first reported intrinsic understanding of the unique GBLgraphite incompatibility and offers valuable insights for the development of wide-temperature and high-safety LIBs.
基金financially supporting from the Key-Area Research and Development Program of Guangdong Province(2020B090919005)the Fundamental Research Funds for the Central Universities(HIT.OCEF.2021008)+2 种基金the Key Research and Development Program of Heilongjiang Province(GA21A102)the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0958)the National Natural Science Foundation of China(51772068)。
文摘Macro-and micro-interface instability of SiO_(x)anode caused by its dramatic volume variation during cycling will result in low Coulombic efficiency and rapid capacity degradation.In this work,an organic-inorganic composite interfacial layer rich in benzene ring groups,polyisocyanates,and LiF was obtained on SiO_(x)anode by the introduction of 4-fluorophenyl isocyanate(FPI)and fluoroethylene carbonate(FEC)co-additives in electrolyte.The SiO_(x)anode material shows a capacity retention of 69.2%after 100 cycles at a current density of 1 A g^(-1)and rate capacity of 523 m A h g^(-1)at the current density of 3A g^(-1),while the SiO_(x)anode cycling in reference electrolyte has almost no capacity.
基金supported financially by the National Natural Science Foundation of China(no.21706043).
文摘Lithium-ion batteries with polymer electrolytes(PEs)are promising candidates for high safety performance batteries.However,conventional PEs suffer from poor compatibility and high impedance of electrolyte-electrode interfaces.Herein,we present a method of the interfacial modification for PEs to inhibit lithium dendrites based on the solution to the interfacial compatibility.Our strategy is to improve the interfacial properties and inhibit the dendrite generation by coating a modified layer on PEs of the anode side with acetylene black(AB)and MXene.The mixed conductive layer(MCL)can promote the generation of Li3N and LiF with a uniform arrangement of electrons to form a dense solid electrolyte interphase layer and the even lithium-ion deposition for improving the performance and stability of the battery during cycling.After adding the MCL,the discharge capacity of solid lithium-ion batteries(SLIBs)with lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)/organic modified montmorillonite(OMMT)/soybean isolate protein(SPI)/poly(vinylidene fluoride)(PVDF)(LOSP)PE from 74.2 mAh g^(-1)up to 111.1 mAh g^(-1)(AB-LiTFSI/OMMT/SPI/PVDF(AB-LOSP))and 111.6 mAh g^(-1)(AB/MXene-LiTFSI/OMMT/SPI/PVDF(AB/MXene-LOSP)).The polarization voltage dropped by 0.06 and 0.12 V,respectively.This work represents a milestone in the dendrite-free SLIBs with good performances.
