At present,developing a simple strategy to effectively solve the shackles of volume expansion,poor conductivity and interface compatibility faced by Si-C anode in lithium batteries(LIBs)is the key to its commercializa...At present,developing a simple strategy to effectively solve the shackles of volume expansion,poor conductivity and interface compatibility faced by Si-C anode in lithium batteries(LIBs)is the key to its commercialization.Here,low-cost nano-Si powders were prepared from Si-waste of solar-cells by sanding treatment,which can effectively reduce the commercialization cost for Si-C anode.Furthermore,micro-nano structured Gr@Si/C/TiO_(2) anode materials with graphite(Gr)as the inner core,TiO_(2)-doped and carbon-coated Si as the outer coating-layer,were synthesized at kilogram-scale per milling batch.Comprehensive characterization results indicate that TiO_(2)-doped carbon layer can improve the interface compatibility with the electrolyte,further promote the reduction of electrode polarization,and finally enhance the battery performance for the Gr@Si/C/TiO_(2) anodes.Accordingly,Gr@Si/C/TiO_(2) composites can output excellent LIB performance,especially with high initial coulombic efficiency(ICE)of 82.51%and large average reversible capacity of~810 mA h g^(-1) at 0.8 A g^(-1) after 1000 cycles.Moreover,Gr@Si/C/TiO_(2)‖NCM811 pouch full cells deliver impressive performance especially with high energy density of~489.3 W h kg^(-1) based on the total weight of active materials,suggesting its promising application in the high performance LIBs.展开更多
Nanocomposites of graphene quantum dots(GQDs)modified gadolinium oxide(Gd_(2)O_(3))particles were successfully synthesized.In addition,the effects of the amount of GQDs and the particle size of Gd_(2)O_(3)on the prope...Nanocomposites of graphene quantum dots(GQDs)modified gadolinium oxide(Gd_(2)O_(3))particles were successfully synthesized.In addition,the effects of the amount of GQDs and the particle size of Gd_(2)O_(3)on the properties of nanocomposites were investigated.The structures and properties of nanoparticles were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,field emission scanning electron microscopy,transmission electron microscopy,photoluminescence spectrometry,and magnetic resonance imaging.The results show that the synthesized particles Gd_(2)O_(3)/GQD are spherical with a diameter of approximately 40 nm and have excellent fluorescence and magnetic property,and its relaxation rate(r_(1)=25.18(mmol/L)^(-1)/s)is higher than that of the typical commercial contrast agents Gd-DTPA(r_(1)=4.5(mmol/L)^(-1)/s),The fluorescence property of Gd_(2)O_(3)/GQD is optimized by varying the V_(GQDs):V_(Gd2O3)ratio,and 1:1 ratio of V_(GQDs):V_(Gd2O3)results in the best fluorescence property.The large particles of Gd_(2)O_(3)improve the relaxation property of nanocomposites.Therefore,the nanocomposites Gd_(2)O_(3)/GQD with magnetic and fluorescence characteristics can be used in biological imaging,drug targeting,and in-vivo diagnostic analysis.展开更多
基金jointly supported by the Natural Science Foundations of China(22179020,12174057)the Fujian Natural Science Foundation for Distinguished Young Scholars(2020J06042)+1 种基金the Foreign Science and Technology Cooperation Project of Fuzhou Science and Technology Bureau(2021-Y-086)the Cultivation plan of outstanding young scientific research talents of Fujian Education Department(J1-1323)。
文摘At present,developing a simple strategy to effectively solve the shackles of volume expansion,poor conductivity and interface compatibility faced by Si-C anode in lithium batteries(LIBs)is the key to its commercialization.Here,low-cost nano-Si powders were prepared from Si-waste of solar-cells by sanding treatment,which can effectively reduce the commercialization cost for Si-C anode.Furthermore,micro-nano structured Gr@Si/C/TiO_(2) anode materials with graphite(Gr)as the inner core,TiO_(2)-doped and carbon-coated Si as the outer coating-layer,were synthesized at kilogram-scale per milling batch.Comprehensive characterization results indicate that TiO_(2)-doped carbon layer can improve the interface compatibility with the electrolyte,further promote the reduction of electrode polarization,and finally enhance the battery performance for the Gr@Si/C/TiO_(2) anodes.Accordingly,Gr@Si/C/TiO_(2) composites can output excellent LIB performance,especially with high initial coulombic efficiency(ICE)of 82.51%and large average reversible capacity of~810 mA h g^(-1) at 0.8 A g^(-1) after 1000 cycles.Moreover,Gr@Si/C/TiO_(2)‖NCM811 pouch full cells deliver impressive performance especially with high energy density of~489.3 W h kg^(-1) based on the total weight of active materials,suggesting its promising application in the high performance LIBs.
基金Project supported by Guizhou Provincial Education Department Project(2017016)Guizhou Science and Technology Project(20192165)。
文摘Nanocomposites of graphene quantum dots(GQDs)modified gadolinium oxide(Gd_(2)O_(3))particles were successfully synthesized.In addition,the effects of the amount of GQDs and the particle size of Gd_(2)O_(3)on the properties of nanocomposites were investigated.The structures and properties of nanoparticles were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,field emission scanning electron microscopy,transmission electron microscopy,photoluminescence spectrometry,and magnetic resonance imaging.The results show that the synthesized particles Gd_(2)O_(3)/GQD are spherical with a diameter of approximately 40 nm and have excellent fluorescence and magnetic property,and its relaxation rate(r_(1)=25.18(mmol/L)^(-1)/s)is higher than that of the typical commercial contrast agents Gd-DTPA(r_(1)=4.5(mmol/L)^(-1)/s),The fluorescence property of Gd_(2)O_(3)/GQD is optimized by varying the V_(GQDs):V_(Gd2O3)ratio,and 1:1 ratio of V_(GQDs):V_(Gd2O3)results in the best fluorescence property.The large particles of Gd_(2)O_(3)improve the relaxation property of nanocomposites.Therefore,the nanocomposites Gd_(2)O_(3)/GQD with magnetic and fluorescence characteristics can be used in biological imaging,drug targeting,and in-vivo diagnostic analysis.