Five kinds of multi - walled carbon nanotubes were prepared by CVD(Chemical Vapour Deposition)and puri - fied under the same conditions,then were used as electrodes for super capacitors in order to compare their per -...Five kinds of multi - walled carbon nanotubes were prepared by CVD(Chemical Vapour Deposition)and puri - fied under the same conditions,then were used as electrodes for super capacitors in order to compare their per - formance.The differences measured in terms of specific capacitance by galvanostatic cycling were presented,porosity measurements using nitrogen at77K made on carbon nanotubes allowd a better understanding of the electrochemical behavior of these carbon nanotubes.The experiment results show that pore diameter in the range of more than3nm is required to maximize the capacitance in the electrolyte of1.0mol · L -1 LiClO 4 /EC+DEC(V EC ∶ V DEC =1 ∶ 1),and the BET surface area contributed by this extent is almost linear with the specific capacitance,in which an average value is about0.11F · m -2 ,and the specific capacitance estimated from above is very close to the value by experiment.展开更多
Transition metal sulfides are considered promising anode materials for sodium-ion batteries(SIBs)due to their high theoretical capacity and low synthesis cost.However,is-sues such as poor cyclic stability and rate per...Transition metal sulfides are considered promising anode materials for sodium-ion batteries(SIBs)due to their high theoretical capacity and low synthesis cost.However,is-sues such as poor cyclic stability and rate performance,arising from volume expansion and structural degradation,remain sig-nificant challenges.We report a novel FeS_(2)/CoS_(2) heterostruc-ture embedded in a 3D carbon aerogel matrix(FeS_(2)/CoS_(2)@C)synthesized by a cross-linking and vulcanization process.The resulting core-shell structure,with bimetallic FeS_(2)/CoS_(2) nano-particles encapsulated in a conductive carbon shell,effectively reduces the adverse effects of volume changes during sodiation/desodiation cycles.The 3D porous carbon network increases both ion and electron diffusion,while preventing agglomeration of the active material and maintaining interface integrity.The FeS_(2)/CoS_(2)@C composite has an outstanding electrochemical performance,including a high specific capacity of 725 mAh g^(-1)at 0.5 A g^(-1)and an exceptional rate capability of 572 mAh g^(-1)at 10 A g^(-1).It also has remarkable cycling stability with no signific-ant capacity decay over 1000 cycles at 5 A g^(-1).展开更多
文摘Five kinds of multi - walled carbon nanotubes were prepared by CVD(Chemical Vapour Deposition)and puri - fied under the same conditions,then were used as electrodes for super capacitors in order to compare their per - formance.The differences measured in terms of specific capacitance by galvanostatic cycling were presented,porosity measurements using nitrogen at77K made on carbon nanotubes allowd a better understanding of the electrochemical behavior of these carbon nanotubes.The experiment results show that pore diameter in the range of more than3nm is required to maximize the capacitance in the electrolyte of1.0mol · L -1 LiClO 4 /EC+DEC(V EC ∶ V DEC =1 ∶ 1),and the BET surface area contributed by this extent is almost linear with the specific capacitance,in which an average value is about0.11F · m -2 ,and the specific capacitance estimated from above is very close to the value by experiment.
文摘Transition metal sulfides are considered promising anode materials for sodium-ion batteries(SIBs)due to their high theoretical capacity and low synthesis cost.However,is-sues such as poor cyclic stability and rate performance,arising from volume expansion and structural degradation,remain sig-nificant challenges.We report a novel FeS_(2)/CoS_(2) heterostruc-ture embedded in a 3D carbon aerogel matrix(FeS_(2)/CoS_(2)@C)synthesized by a cross-linking and vulcanization process.The resulting core-shell structure,with bimetallic FeS_(2)/CoS_(2) nano-particles encapsulated in a conductive carbon shell,effectively reduces the adverse effects of volume changes during sodiation/desodiation cycles.The 3D porous carbon network increases both ion and electron diffusion,while preventing agglomeration of the active material and maintaining interface integrity.The FeS_(2)/CoS_(2)@C composite has an outstanding electrochemical performance,including a high specific capacity of 725 mAh g^(-1)at 0.5 A g^(-1)and an exceptional rate capability of 572 mAh g^(-1)at 10 A g^(-1).It also has remarkable cycling stability with no signific-ant capacity decay over 1000 cycles at 5 A g^(-1).
文摘研究应用于锂二次电池阴极的新型高能量密度存贮材料 L i( Alx Co1- x) O2 的充放电特性 ,并与相同条件下制备的传统材料 L i Co O2 进行对比 .结果表明 ,70 0℃烧结的Li( Al0 .3 Co0 .7) O2 有较好的充放电平台 ,电化学容量大于同样条件下制备的 Li Co O2 .
