The structure evolution of fluorinated graphite （CFx） upon the Li/Na intercalation has been studied by first- principles calculations. The Li/Na adsorption on single CF layer and intercalated into bulk CF have been ...The structure evolution of fluorinated graphite （CFx） upon the Li/Na intercalation has been studied by first- principles calculations. The Li/Na adsorption on single CF layer and intercalated into bulk CF have been calculated. The better cycling performance of Na intercalation into the CF cathode, comparing to that of Li intercalation, is attributed to the different strength and characteristics of the Li-F and Na-F interactions. The interactions between Li and F are stronger and more localized than those between Na and E The strong and localized Coulomb attraction between Li and F atoms breaks the C-F bonds and pulls the F atoms away, and graphene sheets are formed upon Li intercalation.展开更多
A highly stable zinc metal anode modified with a fluorinated graphite nanosheets(FGNSs)coating was designed.The porous structure of the coating layer effectively hinders lateral mass transfer of Zn ions and suppresses...A highly stable zinc metal anode modified with a fluorinated graphite nanosheets(FGNSs)coating was designed.The porous structure of the coating layer effectively hinders lateral mass transfer of Zn ions and suppresses dendrite growth.Moreover,the high electronegativity exhibited by fluorine atoms creates an almost superhydrophobic solid-liquid interface,thereby reducing the interaction between solvent water and the zinc substrate.Consequently,this leads to a significant inhibition of hydrogen evolution corrosion and other side reactions.The modified anode demonstrates exceptional cycling stability,as symmetric cells exhibit sustained cycling for over 1400 h at a current density of 5 mA/cm^(2).Moreover,the full cells with NH_(4)V_(4)O_(10)cathode exhibit an impressive capacity retention rate of 92.2%after undergoing 1000 cycles.展开更多
Chromium oxides(CrO_(x))and fluorinated graphite(CF_(x))are two typical cathode materials for lithium primary batteries.The former owns the highest theoretical energy density,but suffers from poor low practical capaci...Chromium oxides(CrO_(x))and fluorinated graphite(CF_(x))are two typical cathode materials for lithium primary batteries.The former owns the highest theoretical energy density,but suffers from poor low practical capacity and inferior rate capability;the latter has the highest theoretical discharge capacity,but fails to fast discharge.It is desirable to combine the merits of the two cathodes by designing a composite cathode.However,the electrochemical performance of the composite cathode is still far from satisfactory.In this work,we identified that by regulating the overlapped discharge potential of these two cathodes,the F atom will migrate from CF_(x) to CrO_(x),thus leading to a homogeneous distribution of LiF and improved ionic and electronic conductivity,eventually enhancing the high-rate discharge performance.Benefiting from the synergetic effect,the CrO_(x)/10%eCF_(x) composite exhibits a considerably high energy density of 496.59 Wh kg^(−1) at a power density of 49.7 kW kg^(−1)(50C),which is far superior to the pure CrO_(x) and CF_(x) electrodes.We believe that the high-performance CrO_(x)/eCF_(x) composite cathode will justify its practical application in revitalizing advanced lithium primary batteries.展开更多
基金support of National High Technology Research and Development Program of China ("863" Program) (2015AA034201)the National Natural Science Foundation of China (11234013 and 11264014)+1 种基金Natural Science Foundation of Jiangxi Province (20133ACB21010, 20142BAB212002,20132BAB212005)Foundation of Jiangxi Education Committee (GJJ14254 and KJLD14024)
文摘The structure evolution of fluorinated graphite （CFx） upon the Li/Na intercalation has been studied by first- principles calculations. The Li/Na adsorption on single CF layer and intercalated into bulk CF have been calculated. The better cycling performance of Na intercalation into the CF cathode, comparing to that of Li intercalation, is attributed to the different strength and characteristics of the Li-F and Na-F interactions. The interactions between Li and F are stronger and more localized than those between Na and E The strong and localized Coulomb attraction between Li and F atoms breaks the C-F bonds and pulls the F atoms away, and graphene sheets are formed upon Li intercalation.
基金supported by Young Elite Scientists Sponsorship Program by CAST,China(No.2023QNRC001)the Science and Technology Innovation Program of Hunan Province,China(No.2022RC1078)+1 种基金the Natural Science Foundation of Hunan Province,China(No.2023JJ10060)the Scientific Research Fund of Hunan Provincial Education Department,China(No.23A0003)。
文摘A highly stable zinc metal anode modified with a fluorinated graphite nanosheets(FGNSs)coating was designed.The porous structure of the coating layer effectively hinders lateral mass transfer of Zn ions and suppresses dendrite growth.Moreover,the high electronegativity exhibited by fluorine atoms creates an almost superhydrophobic solid-liquid interface,thereby reducing the interaction between solvent water and the zinc substrate.Consequently,this leads to a significant inhibition of hydrogen evolution corrosion and other side reactions.The modified anode demonstrates exceptional cycling stability,as symmetric cells exhibit sustained cycling for over 1400 h at a current density of 5 mA/cm^(2).Moreover,the full cells with NH_(4)V_(4)O_(10)cathode exhibit an impressive capacity retention rate of 92.2%after undergoing 1000 cycles.
基金financially supported by the Defense Industrial Technology Development Program(JCKY2021211B014)。
文摘Chromium oxides(CrO_(x))and fluorinated graphite(CF_(x))are two typical cathode materials for lithium primary batteries.The former owns the highest theoretical energy density,but suffers from poor low practical capacity and inferior rate capability;the latter has the highest theoretical discharge capacity,but fails to fast discharge.It is desirable to combine the merits of the two cathodes by designing a composite cathode.However,the electrochemical performance of the composite cathode is still far from satisfactory.In this work,we identified that by regulating the overlapped discharge potential of these two cathodes,the F atom will migrate from CF_(x) to CrO_(x),thus leading to a homogeneous distribution of LiF and improved ionic and electronic conductivity,eventually enhancing the high-rate discharge performance.Benefiting from the synergetic effect,the CrO_(x)/10%eCF_(x) composite exhibits a considerably high energy density of 496.59 Wh kg^(−1) at a power density of 49.7 kW kg^(−1)(50C),which is far superior to the pure CrO_(x) and CF_(x) electrodes.We believe that the high-performance CrO_(x)/eCF_(x) composite cathode will justify its practical application in revitalizing advanced lithium primary batteries.
