The simplest zeolite,sodalite(SOD),was synthesized iononic liquid-thermally from aqueous basic aluminosilicate precursor gels in an imidazolium-based ionic liquid,with 1-ethyl-3-methylimidazolium bromide as solvent.Th...The simplest zeolite,sodalite(SOD),was synthesized iononic liquid-thermally from aqueous basic aluminosilicate precursor gels in an imidazolium-based ionic liquid,with 1-ethyl-3-methylimidazolium bromide as solvent.The synthesis was carried out at a temperature between 50 and 150 ℃ at an ambient pressure.The effects of mass ratios of aqueous gel to ionic liquid,molar ratios of n(Si)/n(Al) in gel and crystallization temperature and time on the crystallization were investigated.The morphology and structure of the as-prepared products were characterized by X-ray diffraction and scanning electron microscopy.The results show that a mixture of sodalite and zeolite X was initially precipitated in ionic liquid at a ratio 1∶3 of aqueous gel to ionic liquid,and finally transformed in to pure sodalite as the crystallisation time is prolonged,and the crystallinity of sodalite increased with the increase of n(Si)/n(Al) from 1.1 to 10.Increasing the ratio of aqueous gel to ionic liquid,zeolite X was favorable to crystallize,and it became the only product under the hydrothermal condition.展开更多
以二乙醇胺乳酸盐为反应介质,采用离子热法在180℃制备LiFePO4和LiFe0.95Ni0.05PO4,利用蔗糖在650℃分解覆炭得到LiFe0.95Ni0.05PO4/C复合材料。结果表明:LiFePO4及其掺杂改性物均为橄榄石晶体结构,少量Ni的掺杂导致材料粒度和形貌变化...以二乙醇胺乳酸盐为反应介质,采用离子热法在180℃制备LiFePO4和LiFe0.95Ni0.05PO4,利用蔗糖在650℃分解覆炭得到LiFe0.95Ni0.05PO4/C复合材料。结果表明:LiFePO4及其掺杂改性物均为橄榄石晶体结构,少量Ni的掺杂导致材料粒度和形貌变化,短轴尺寸约为300nm的棒状材料变为尺寸约为200nm的纺锤体状复合材料。恒电流充放电测试结果表明:在室温及0.1C倍率下,LiFePO4、LiFe0.95Ni0.05PO4和LiFe0.95Ni0.05PO4/C首次放电比容量分别为135.2、140.1mA h/g和165.4 mA h/g,LiFe0.95Ni0.05PO4/C在不同倍率下循环30次均无明显衰减。展开更多
Co-crystalline zeolite FAU/LTA-0 was synthesized by hydrothermal method from lithium slag. To make the most of excess silicon and alkali sources in mother liquid derived from FAU/LTA-0, zeolite FAU/LTA-I b was synthes...Co-crystalline zeolite FAU/LTA-0 was synthesized by hydrothermal method from lithium slag. To make the most of excess silicon and alkali sources in mother liquid derived from FAU/LTA-0, zeolite FAU/LTA-I b was synthesized in the same method with the use of mother liquid by adding a certain amount of aluminum source. Influences of different adding ways of aluminum source and recycling dosages of mother liquid on synthesis of zeolites FALl/ LTA with mother liquid were investigated. The phase, microstructure and thermostability of FAU/LTA-0 and FAU/LTA-lb were characterized by XRD, SEM and TG-DTA. The calcium and magnesium cation exchange capacities （CECs） of the zeolites were determined. The results have shown that co-crystalline zeolite can be synthesized with the use of mother liquid by adding aluminum source after 2 h of reaction. Compared with FAU/LTA-0, the crystal twinning structure of FAU/LTA-lb became weaker, the grain size was smaller, and the thermostability was better. With a lower dosage of mother liquid, the content of P-type impurity in product decreased significantly, and the content of LTA phase increased. The reuse rate of mother liquid can reach 48%. The CECs of FAU/LTA-I b-150 can reach 343 mg CaCO3. g-1 and 180 mg MgC03. g-1, showing more excellent adsorption capacities than FAU/LTA-0 and commercial zeolite 4A. The full recycling use of mother liquid to synthesize zeolite FAU/LTA which can be applied for detergent not only improves resource utilization but also reduces oroduction cost.展开更多
A nano-Li3V2（PO4）3/C powder was successfully prepared by a thermal polymerization method. The particle sizes of the intermediate product powder and the final product Li3V2（PO4）3 are all less than 200 nm. The carbo...A nano-Li3V2（PO4）3/C powder was successfully prepared by a thermal polymerization method. The particle sizes of the intermediate product powder and the final product Li3V2（PO4）3 are all less than 200 nm. The carbon is partially coated on the surface of Li3V2（PO4）3 particles and the rest exists between particles with a total carbon content of 4.6wt%. This nano-Li3V2（PO4）3/C sample shows a discharge capacity of 124 mAh/g with-out capacity fading after 100 cycles at 0.1 C in the voltage rang of 3.0-4.3 V. Excellent rate performance is also achieved with a capacity of 80 mAh/g at 20 C in 3.0-4.3 V and 100 mAh/g at 10 C in 3.0-4.8 V. This study suggests that the thermal polymerization method is suitable to synthesize nano-Li3V2（PO4）3/C materials.展开更多
High yields of CoFe204, NiFe204 and CdFe204 hierarchical porous ball-in-ball hollow spheres have been achieved using hydrothermal synthesis followed by calcination. The mechanism of formation is shown to involve an in...High yields of CoFe204, NiFe204 and CdFe204 hierarchical porous ball-in-ball hollow spheres have been achieved using hydrothermal synthesis followed by calcination. The mechanism of formation is shown to involve an in situ carbonaceous-template process. Hierarchical porous CoFe2O4 hollow spheres with different numbers of shells can be obtained by altering the synthesis conditions. The electrochemical properties of the resulting CoFe2O4 electrodes have been compared, using different binders. The as-obtained CoFe2O4 and NiFe2O4 have relatively high reversible discharge capacity and good rate retention performance which make them promising materials for use as anode materials in lithium ion batteries.展开更多
[020]-oriented tin sulfide nanobelts with a length/thickness ratio of 100 have been synthesized by a facile hydrothermal method without any surfactants, and the nanobelts have shown good strain-accommodating propertie...[020]-oriented tin sulfide nanobelts with a length/thickness ratio of 100 have been synthesized by a facile hydrothermal method without any surfactants, and the nanobelts have shown good strain-accommodating properties as well as good electrochemical performance as the anode for Li-ion batteries. The formation of the nanobelts results from a precipitation-dissolution-transformation mechanism, and the [020] oriented growth can be ascribed to the {010} facet family having the lowest atomic density. In particular, SnS shows clear Li-Sn alloying/de-alloying reversible reactions in the potential range 0.1-1.0 V. Based on galvanostatic measurements and electrochemical impedance spectroscopy, SnS nanobelts have shown impressive rate performance. The post-cycled SnS nanobelts were completely transformed into metallic tin, and preserved the one-dimensional structure due to their flexibility which accommodates the large volumetric expansion.展开更多
文摘The simplest zeolite,sodalite(SOD),was synthesized iononic liquid-thermally from aqueous basic aluminosilicate precursor gels in an imidazolium-based ionic liquid,with 1-ethyl-3-methylimidazolium bromide as solvent.The synthesis was carried out at a temperature between 50 and 150 ℃ at an ambient pressure.The effects of mass ratios of aqueous gel to ionic liquid,molar ratios of n(Si)/n(Al) in gel and crystallization temperature and time on the crystallization were investigated.The morphology and structure of the as-prepared products were characterized by X-ray diffraction and scanning electron microscopy.The results show that a mixture of sodalite and zeolite X was initially precipitated in ionic liquid at a ratio 1∶3 of aqueous gel to ionic liquid,and finally transformed in to pure sodalite as the crystallisation time is prolonged,and the crystallinity of sodalite increased with the increase of n(Si)/n(Al) from 1.1 to 10.Increasing the ratio of aqueous gel to ionic liquid,zeolite X was favorable to crystallize,and it became the only product under the hydrothermal condition.
文摘以二乙醇胺乳酸盐为反应介质,采用离子热法在180℃制备LiFePO4和LiFe0.95Ni0.05PO4,利用蔗糖在650℃分解覆炭得到LiFe0.95Ni0.05PO4/C复合材料。结果表明:LiFePO4及其掺杂改性物均为橄榄石晶体结构,少量Ni的掺杂导致材料粒度和形貌变化,短轴尺寸约为300nm的棒状材料变为尺寸约为200nm的纺锤体状复合材料。恒电流充放电测试结果表明:在室温及0.1C倍率下,LiFePO4、LiFe0.95Ni0.05PO4和LiFe0.95Ni0.05PO4/C首次放电比容量分别为135.2、140.1mA h/g和165.4 mA h/g,LiFe0.95Ni0.05PO4/C在不同倍率下循环30次均无明显衰减。
基金Supported by the National Natural Science Foundation of China(51476074)
文摘Co-crystalline zeolite FAU/LTA-0 was synthesized by hydrothermal method from lithium slag. To make the most of excess silicon and alkali sources in mother liquid derived from FAU/LTA-0, zeolite FAU/LTA-I b was synthesized in the same method with the use of mother liquid by adding a certain amount of aluminum source. Influences of different adding ways of aluminum source and recycling dosages of mother liquid on synthesis of zeolites FALl/ LTA with mother liquid were investigated. The phase, microstructure and thermostability of FAU/LTA-0 and FAU/LTA-lb were characterized by XRD, SEM and TG-DTA. The calcium and magnesium cation exchange capacities （CECs） of the zeolites were determined. The results have shown that co-crystalline zeolite can be synthesized with the use of mother liquid by adding aluminum source after 2 h of reaction. Compared with FAU/LTA-0, the crystal twinning structure of FAU/LTA-lb became weaker, the grain size was smaller, and the thermostability was better. With a lower dosage of mother liquid, the content of P-type impurity in product decreased significantly, and the content of LTA phase increased. The reuse rate of mother liquid can reach 48%. The CECs of FAU/LTA-I b-150 can reach 343 mg CaCO3. g-1 and 180 mg MgC03. g-1, showing more excellent adsorption capacities than FAU/LTA-0 and commercial zeolite 4A. The full recycling use of mother liquid to synthesize zeolite FAU/LTA which can be applied for detergent not only improves resource utilization but also reduces oroduction cost.
文摘A nano-Li3V2（PO4）3/C powder was successfully prepared by a thermal polymerization method. The particle sizes of the intermediate product powder and the final product Li3V2（PO4）3 are all less than 200 nm. The carbon is partially coated on the surface of Li3V2（PO4）3 particles and the rest exists between particles with a total carbon content of 4.6wt%. This nano-Li3V2（PO4）3/C sample shows a discharge capacity of 124 mAh/g with-out capacity fading after 100 cycles at 0.1 C in the voltage rang of 3.0-4.3 V. Excellent rate performance is also achieved with a capacity of 80 mAh/g at 20 C in 3.0-4.3 V and 100 mAh/g at 10 C in 3.0-4.8 V. This study suggests that the thermal polymerization method is suitable to synthesize nano-Li3V2（PO4）3/C materials.
文摘High yields of CoFe204, NiFe204 and CdFe204 hierarchical porous ball-in-ball hollow spheres have been achieved using hydrothermal synthesis followed by calcination. The mechanism of formation is shown to involve an in situ carbonaceous-template process. Hierarchical porous CoFe2O4 hollow spheres with different numbers of shells can be obtained by altering the synthesis conditions. The electrochemical properties of the resulting CoFe2O4 electrodes have been compared, using different binders. The as-obtained CoFe2O4 and NiFe2O4 have relatively high reversible discharge capacity and good rate retention performance which make them promising materials for use as anode materials in lithium ion batteries.
基金Acknowledgements This work was supported by the State Key Project of Fundamental Research for Nanoscience and Nano- technology （Nos. 2011CB932401 and 2011CBA00500）, and the National Natural Science Foundation of China （Nos. 20921001 and 21051001）. We are grateful to Associate Professor Jiaping Wang and lab assistant Fei Zhao in the Tsinghua-Foxconn Nanocenter for their generous help in the fabrication of batteries.
文摘[020]-oriented tin sulfide nanobelts with a length/thickness ratio of 100 have been synthesized by a facile hydrothermal method without any surfactants, and the nanobelts have shown good strain-accommodating properties as well as good electrochemical performance as the anode for Li-ion batteries. The formation of the nanobelts results from a precipitation-dissolution-transformation mechanism, and the [020] oriented growth can be ascribed to the {010} facet family having the lowest atomic density. In particular, SnS shows clear Li-Sn alloying/de-alloying reversible reactions in the potential range 0.1-1.0 V. Based on galvanostatic measurements and electrochemical impedance spectroscopy, SnS nanobelts have shown impressive rate performance. The post-cycled SnS nanobelts were completely transformed into metallic tin, and preserved the one-dimensional structure due to their flexibility which accommodates the large volumetric expansion.
