Studying on the anode materials with high energy densities for next-generation lithium-ion batteries(LIBs) is the key for the wide application for electrochemical energy storage devices.Ti-based compounds as promising...Studying on the anode materials with high energy densities for next-generation lithium-ion batteries(LIBs) is the key for the wide application for electrochemical energy storage devices.Ti-based compounds as promising anode materials are known for their outstanding high-rate capacity and cycling stability as well as improved safety over graphite. However, Ti-based materials still suffer from the low capacity, thus largely limiting their commercialized application. Here, we present an overview of the recent development of Ti-based anode materials in LIBs, and special emphasis is placed on capacity enhancement by rational design of hybrid nanocomposites with conversion-/alloying-type anodes. This review is expected to provide a guidance for designing novel Ti-based materials for energy storage and conversion.展开更多
Transition-metal oxides （TMOs） have gradually attracted attention from resear- chers as anode materials for lithium-ion batteries （LIBs） and sodium-ion batteries （SIBs） because of their high theoretical capacity...Transition-metal oxides （TMOs） have gradually attracted attention from resear- chers as anode materials for lithium-ion batteries （LIBs） and sodium-ion batteries （SIBs） because of their high theoretical capacity. However, their poor cycling stability and inferior rate capability resulting from the large volume variation during the lithiation/sodiation process and their low intrinsic electronic con- ductivity limit their applications. To solve the problems of TMOs, carbon-based metal-oxide composites with complex structures derived from metal-organic frameworks （MOFs） have emerged as promising electrode materials for LIBs and SIBs. In this study, we adopted a facile interface-modulated method to synthesize yolk-shell carbon-based Co3O4 dodecahedrons derived from ZIF-67 zeolitic imida- zolate frameworks. This strategy is based on the interface separation between the ZIF-67 core and the carbon-based shell during the pyrolysis process. The unique yolk-shell structure effectively accommodates the volume expansion during lithiation or sodiation, and the carbon matrix improves the electrical conductivity of the electrode. As an anode for LIBs, the yolk-shell Co3O4/C dodecahedrons exhibit a high specific capacity and excellent cycling stability （1,100 mAh.g-1 after 120 cycles at 200 mA-g-1）. As an anode for S1Bs, the composites exhibit an outstand- ing rate capability （307 mAh-g-1 at 1,000 mA-g-1 and 269 mAh.g-1 at 2,000 mA-g-1）. Detailed electrochemical kinetic analysis indicates that the energy storage for Li＋ and Na＋ in yolk-sheU Co3O4/C dodecahedrons shows a dominant capacitive behavior. This work introduces an effective approach for fabricating carbon- based metal-oxide composites by using MOFs as ideal precursors and as electrode materials to enhance the electrochemical performance of LIBs and SIBs.展开更多
Transition metal oxides are promising candidates for the high-capacity anode material in lithium-ion batteries.The electrochemical performance of transition metal oxides can be improved by constructing suitable compos...Transition metal oxides are promising candidates for the high-capacity anode material in lithium-ion batteries.The electrochemical performance of transition metal oxides can be improved by constructing suitable composite architectures. Herein, we demonstrate a metal–organic framework(MOF)-assisted strategy for the synthesis of a hierarchical hybrid nanostructure composed of Fe_2O_3 nanotubes assembled in Co_3O_4 host. Starting from MOF composite precursors(Fe-based MOF encapsulated in a Cobased host matrix), a complex structure of Co_3O_4 host and engulfed Fe_2O_3 nanotubes was prepared by a simple annealing treatment in air. By virtue of their structural and compositional features, these hierarchical composite particles reveal enhanced lithium storage properties when employed as anodes for lithium-ion batteries.展开更多
SnO2 is a promising material for both Li-ion and Na-ion batteries owing to its high theoretical capacities. Unfortunately, the electrochemical performance of SnO2 is unsatisfactory because of the large volume change t...SnO2 is a promising material for both Li-ion and Na-ion batteries owing to its high theoretical capacities. Unfortunately, the electrochemical performance of SnO2 is unsatisfactory because of the large volume change that occurs during cycling, low electronic conductivity of inactive oxide matrix, and poor kinetics, which are particularly severe in Na-ion batteries. Herein, ultra-fine SnO2 nanocrystals anchored on a unique three-dimensional （3D） porous reduced graphene oxide （rGO） matrix are described as promising bifunctional electrodes for Li-ion and Na-ion batteries with excellent rate capability and long cycle life. Ultra-fine SnO2 nanocrystals of size -6 nm are well-coordinated to the graphene sheets that comprise the 3D macro-porous structure. Notably, superior rate capability was obtained up to 3 C （1In C is a measure of the rate that allows the cell to be charged/discharged in n h） for both batteries. In situ X-ray diffractometry measurements during lithiation （or sodiation） and delithiation （or desodiation） were combined with various electrochemical techniques to reveal the real-time phase evolution. This critical information was linked with the internal resistance, ion diffusivity （DLi＋ and DNa＋）, and the unique structure of the composite electrode materials to explain their excellent electrochemical performance. The improved capacity and superior rate capabilities demonstrated in this work can be ascribed to the enhanced transport kinetics of both electrons and ions within the electrode structure because of the well-interconnected, 3D macro-porous rGO matrix. The porous rGO matrix appears to play a more important role in sodium-ion batteries （SIBs）, where the larger mass/radius of Na-ions are marked concerns.展开更多
{3-[2-(2-methoxyethoxy) ethoxy]-propyl} triethoxysilane (TESM2) was synthesized and used as an electrolyte additive to improve the performances of lithium-ion batteries (LIBs). The electrochemical properties of the el...{3-[2-(2-methoxyethoxy) ethoxy]-propyl} triethoxysilane (TESM2) was synthesized and used as an electrolyte additive to improve the performances of lithium-ion batteries (LIBs). The electrochemical properties of the electrolyte (1 mol/L lithium hexafluorophosphate (LiPF 6 )/ethylene carbonate (EC):diethylene carbonate (DEC):dimethyl carbonate (DMC), 1:1:1) with different contents of TESM2 were characterized by ionic conductivity measurement, galvanostatic charge/discharge test of graphite/Li half cells, and electrochemical impedance spectroscopy. Both the cycling performances and C-rate capabilities of graphite/Li half cells were significantly improved with an optimized content of 15% TESM2 in the electrolyte. The graphite/Li half cell delivered a very high specific capacity of 370 mAh/g at 0.2C rate without any capacity loss for 60 cycles, and retained a capacity of 292 mAh/g at 2C rate. The solid electrolyte interphase (SEI) film on the surface of the graphite anode was investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), indicating that TESM2 was effectively involved in the formation of SEI film on the surface of graphite.展开更多
Close packed ZnO nanoparticles on carbon cloth were synthesized by repeating a facile hydrothermal route in this study. After characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, the ob...Close packed ZnO nanoparticles on carbon cloth were synthesized by repeating a facile hydrothermal route in this study. After characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, the obtained ZnO cloth was further studied for the applications in lithium （Li）-ion batteries （LIBs） and dye-sensitized solar cells （DSSCs）. When ZnO cloth annealed at 400℃ for 2 h were used as anodes of LIBs, it exhibited high capacity of 600mAh/g and outstanding cycling capability without significant fading after 130 cycles. Moreover, it was also found that our electrodes displayed good stabilities under various humidity and temperature. Furthermore, the obtained composites were calcined at higher temperature （800℃） to remove carbon and white pure ZnO cloth was formed. We transferred the as-formed ZnO cloth to fluorine-doped tin oxide （FTO） substrate to make DSSCs, exhibiting an improved efficiency of around 0.38% assisted by TiC14 treatment.展开更多
SnO2/ graphite nanocomposites with different SnO2 contents were successfully prepared by a co-precipitation method.The nanocomposites, used as the anode material for lithium-ion batteries( LIBs),were characterized by ...SnO2/ graphite nanocomposites with different SnO2 contents were successfully prepared by a co-precipitation method.The nanocomposites, used as the anode material for lithium-ion batteries( LIBs),were characterized by X-ray diffraction( XRD),thermogravimetric analysis( TGA), and transmission electron microscopy( TEM). The SnO2 particles had the average size of about 15 nm and their distribution on graphite matrix much depended on the contents of SnO2 in the nanocomposites. The galvanostatic charge-discharge cycles were used to investigate the effects of SnO2 contents on the electrochemical performance of these composites. The results show that the initial specific capacities increase with the SnO2 contents. However,the cyclic stabilities are determined by the distribution of SnO2 particles in composites. For55% by weight SnO2/ graphite composites, the initial specific capacity is 740 m Ah g- 1and 70% of the initial specific capacity( 518 m Ah·g- 1) can still be retained after 50 charge-discharge cycles.展开更多
The demand of higher energy density and higher power capacity of lithium（Li）-ion secondary batteries has led to the search for electrode materials whose capacities and performance are better than those available tod...The demand of higher energy density and higher power capacity of lithium（Li）-ion secondary batteries has led to the search for electrode materials whose capacities and performance are better than those available today. Carbon nanotubes（CNTs）, with their unique properties such as 1D tubular structure, high electrical and thermal conductivities, and extremely large surface area, have been used as materials to prepare cathodes for Li-ion batteries. The structure and morphology of CNTs were analyzed by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, and transmission electron microscopy（TEM）. The functional groups on the purified CNT surface such as –COOH, –OH were characterized by Fourier Transform infrared spectroscopy. The electrode materials were fabricated from LiMn2O4（LMO）, doped spinel LiNi0.5Mn1.5O4, and purified CNTs via solid-state reaction. The structure and morphology of the electrode were characterized using XRD, SEM, and TEM. Finally, the efficiency of the electrode materials using CNTs was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 51472137 and 51772163)
文摘Studying on the anode materials with high energy densities for next-generation lithium-ion batteries(LIBs) is the key for the wide application for electrochemical energy storage devices.Ti-based compounds as promising anode materials are known for their outstanding high-rate capacity and cycling stability as well as improved safety over graphite. However, Ti-based materials still suffer from the low capacity, thus largely limiting their commercialized application. Here, we present an overview of the recent development of Ti-based anode materials in LIBs, and special emphasis is placed on capacity enhancement by rational design of hybrid nanocomposites with conversion-/alloying-type anodes. This review is expected to provide a guidance for designing novel Ti-based materials for energy storage and conversion.
基金This work was supported by the National Key Research and Development Program of China （No. 2016YFA0202603）, the National Basic Research Program of China （No. 2013CB934103）, the National Natural Science Foundation of China （Nos. 51521001 and 51272197）, the National Natural Science Fund for Distinguished Young Scholars （No. 51425204）, the Fundamental Research Funds for the Central Universities （WUT： 22016III001, 2017IVA096） and the Foundation of National Excellent Doctoral Dissertation of PR China （No. 2016-YB-004） Prof. Liqiang Mai gratefully acknowledges the financial support from China Scholarship Council （No. 201606955096）.
文摘Transition-metal oxides （TMOs） have gradually attracted attention from resear- chers as anode materials for lithium-ion batteries （LIBs） and sodium-ion batteries （SIBs） because of their high theoretical capacity. However, their poor cycling stability and inferior rate capability resulting from the large volume variation during the lithiation/sodiation process and their low intrinsic electronic con- ductivity limit their applications. To solve the problems of TMOs, carbon-based metal-oxide composites with complex structures derived from metal-organic frameworks （MOFs） have emerged as promising electrode materials for LIBs and SIBs. In this study, we adopted a facile interface-modulated method to synthesize yolk-shell carbon-based Co3O4 dodecahedrons derived from ZIF-67 zeolitic imida- zolate frameworks. This strategy is based on the interface separation between the ZIF-67 core and the carbon-based shell during the pyrolysis process. The unique yolk-shell structure effectively accommodates the volume expansion during lithiation or sodiation, and the carbon matrix improves the electrical conductivity of the electrode. As an anode for LIBs, the yolk-shell Co3O4/C dodecahedrons exhibit a high specific capacity and excellent cycling stability （1,100 mAh.g-1 after 120 cycles at 200 mA-g-1）. As an anode for S1Bs, the composites exhibit an outstand- ing rate capability （307 mAh-g-1 at 1,000 mA-g-1 and 269 mAh.g-1 at 2,000 mA-g-1）. Detailed electrochemical kinetic analysis indicates that the energy storage for Li＋ and Na＋ in yolk-sheU Co3O4/C dodecahedrons shows a dominant capacitive behavior. This work introduces an effective approach for fabricating carbon- based metal-oxide composites by using MOFs as ideal precursors and as electrode materials to enhance the electrochemical performance of LIBs and SIBs.
文摘Transition metal oxides are promising candidates for the high-capacity anode material in lithium-ion batteries.The electrochemical performance of transition metal oxides can be improved by constructing suitable composite architectures. Herein, we demonstrate a metal–organic framework(MOF)-assisted strategy for the synthesis of a hierarchical hybrid nanostructure composed of Fe_2O_3 nanotubes assembled in Co_3O_4 host. Starting from MOF composite precursors(Fe-based MOF encapsulated in a Cobased host matrix), a complex structure of Co_3O_4 host and engulfed Fe_2O_3 nanotubes was prepared by a simple annealing treatment in air. By virtue of their structural and compositional features, these hierarchical composite particles reveal enhanced lithium storage properties when employed as anodes for lithium-ion batteries.
文摘SnO2 is a promising material for both Li-ion and Na-ion batteries owing to its high theoretical capacities. Unfortunately, the electrochemical performance of SnO2 is unsatisfactory because of the large volume change that occurs during cycling, low electronic conductivity of inactive oxide matrix, and poor kinetics, which are particularly severe in Na-ion batteries. Herein, ultra-fine SnO2 nanocrystals anchored on a unique three-dimensional （3D） porous reduced graphene oxide （rGO） matrix are described as promising bifunctional electrodes for Li-ion and Na-ion batteries with excellent rate capability and long cycle life. Ultra-fine SnO2 nanocrystals of size -6 nm are well-coordinated to the graphene sheets that comprise the 3D macro-porous structure. Notably, superior rate capability was obtained up to 3 C （1In C is a measure of the rate that allows the cell to be charged/discharged in n h） for both batteries. In situ X-ray diffractometry measurements during lithiation （or sodiation） and delithiation （or desodiation） were combined with various electrochemical techniques to reveal the real-time phase evolution. This critical information was linked with the internal resistance, ion diffusivity （DLi＋ and DNa＋）, and the unique structure of the composite electrode materials to explain their excellent electrochemical performance. The improved capacity and superior rate capabilities demonstrated in this work can be ascribed to the enhanced transport kinetics of both electrons and ions within the electrode structure because of the well-interconnected, 3D macro-porous rGO matrix. The porous rGO matrix appears to play a more important role in sodium-ion batteries （SIBs）, where the larger mass/radius of Na-ions are marked concerns.
基金supported by the National Natural Science Foundation of China (No. 50973112)the Hundred Talents Program of the Chinese Academy of Sciences (CAS), the CAS-Guangdong Collaboration Program (No. 20108)+1 种基金the Science & Technology Project of Guangzhou (No. 11A44061500)the Amperex Technology Ltd. (China)
文摘{3-[2-(2-methoxyethoxy) ethoxy]-propyl} triethoxysilane (TESM2) was synthesized and used as an electrolyte additive to improve the performances of lithium-ion batteries (LIBs). The electrochemical properties of the electrolyte (1 mol/L lithium hexafluorophosphate (LiPF 6 )/ethylene carbonate (EC):diethylene carbonate (DEC):dimethyl carbonate (DMC), 1:1:1) with different contents of TESM2 were characterized by ionic conductivity measurement, galvanostatic charge/discharge test of graphite/Li half cells, and electrochemical impedance spectroscopy. Both the cycling performances and C-rate capabilities of graphite/Li half cells were significantly improved with an optimized content of 15% TESM2 in the electrolyte. The graphite/Li half cell delivered a very high specific capacity of 370 mAh/g at 0.2C rate without any capacity loss for 60 cycles, and retained a capacity of 292 mAh/g at 2C rate. The solid electrolyte interphase (SEI) film on the surface of the graphite anode was investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), indicating that TESM2 was effectively involved in the formation of SEI film on the surface of graphite.
文摘Close packed ZnO nanoparticles on carbon cloth were synthesized by repeating a facile hydrothermal route in this study. After characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, the obtained ZnO cloth was further studied for the applications in lithium （Li）-ion batteries （LIBs） and dye-sensitized solar cells （DSSCs）. When ZnO cloth annealed at 400℃ for 2 h were used as anodes of LIBs, it exhibited high capacity of 600mAh/g and outstanding cycling capability without significant fading after 130 cycles. Moreover, it was also found that our electrodes displayed good stabilities under various humidity and temperature. Furthermore, the obtained composites were calcined at higher temperature （800℃） to remove carbon and white pure ZnO cloth was formed. We transferred the as-formed ZnO cloth to fluorine-doped tin oxide （FTO） substrate to make DSSCs, exhibiting an improved efficiency of around 0.38% assisted by TiC14 treatment.
基金the Scientific Research Foundation for the Returned Overseas Chinese Scholarsthe Shanghai Leading Academic Discipline Project,China(No.B603)the Programme of Introducing Talents of Discipline to Universities,China(No.111-2-04)
文摘SnO2/ graphite nanocomposites with different SnO2 contents were successfully prepared by a co-precipitation method.The nanocomposites, used as the anode material for lithium-ion batteries( LIBs),were characterized by X-ray diffraction( XRD),thermogravimetric analysis( TGA), and transmission electron microscopy( TEM). The SnO2 particles had the average size of about 15 nm and their distribution on graphite matrix much depended on the contents of SnO2 in the nanocomposites. The galvanostatic charge-discharge cycles were used to investigate the effects of SnO2 contents on the electrochemical performance of these composites. The results show that the initial specific capacities increase with the SnO2 contents. However,the cyclic stabilities are determined by the distribution of SnO2 particles in composites. For55% by weight SnO2/ graphite composites, the initial specific capacity is 740 m Ah g- 1and 70% of the initial specific capacity( 518 m Ah·g- 1) can still be retained after 50 charge-discharge cycles.
基金supported by a Grant Research of Vietnam National University,Ho Chi Minh City(No.B2012-20-10TD)
文摘The demand of higher energy density and higher power capacity of lithium（Li）-ion secondary batteries has led to the search for electrode materials whose capacities and performance are better than those available today. Carbon nanotubes（CNTs）, with their unique properties such as 1D tubular structure, high electrical and thermal conductivities, and extremely large surface area, have been used as materials to prepare cathodes for Li-ion batteries. The structure and morphology of CNTs were analyzed by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, and transmission electron microscopy（TEM）. The functional groups on the purified CNT surface such as –COOH, –OH were characterized by Fourier Transform infrared spectroscopy. The electrode materials were fabricated from LiMn2O4（LMO）, doped spinel LiNi0.5Mn1.5O4, and purified CNTs via solid-state reaction. The structure and morphology of the electrode were characterized using XRD, SEM, and TEM. Finally, the efficiency of the electrode materials using CNTs was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy.
