Due to the high capacity and moderate volume expansion of silicon protoxide SiO_(x)(160%)compared with that of Si(300%),reducing silicon dioxide SiO_(2)into SiO_(x)while maintaining its special nano-morphology makes i...Due to the high capacity and moderate volume expansion of silicon protoxide SiO_(x)(160%)compared with that of Si(300%),reducing silicon dioxide SiO_(2)into SiO_(x)while maintaining its special nano-morphology makes it attractive as an anode of Li-ion batteries.Herein,through a one-pot facile high-temperature annealing route,using SBA15 as the silicon source,and embedding tin dioxide SnO_(2)particles into carbon coated SiO_(x),the mesoporous SiO_(x)-SnO_(2)@C rod composite was prepared and tested as the anode material.The results revealed that the SnO_(2)particles were distributed uniformly in the wall,which could further improve their volume energy densities.The coated carbon plays a role in maintaining structural integrality during lithiation,and the rich mesopores structure can release the expanded volume and enhance Li-ion transfer.At 0.1 A·g^(-1),the gravimetric and volumetric capacities of the composite were as high as 1271 mAh·g^(-1)and 1573 mAh·cm^(-3),respectively.After 200 cycles,the 95%capacity could be retained compared with that upon the 2nd cycle at 0.5 A·g^(-1).And the rod morphology was well kept,except that the diameter of the rod was 3 times larger than its original size after the cell was discharged into 0.01 V.展开更多
文摘Due to the high capacity and moderate volume expansion of silicon protoxide SiO_(x)(160%)compared with that of Si(300%),reducing silicon dioxide SiO_(2)into SiO_(x)while maintaining its special nano-morphology makes it attractive as an anode of Li-ion batteries.Herein,through a one-pot facile high-temperature annealing route,using SBA15 as the silicon source,and embedding tin dioxide SnO_(2)particles into carbon coated SiO_(x),the mesoporous SiO_(x)-SnO_(2)@C rod composite was prepared and tested as the anode material.The results revealed that the SnO_(2)particles were distributed uniformly in the wall,which could further improve their volume energy densities.The coated carbon plays a role in maintaining structural integrality during lithiation,and the rich mesopores structure can release the expanded volume and enhance Li-ion transfer.At 0.1 A·g^(-1),the gravimetric and volumetric capacities of the composite were as high as 1271 mAh·g^(-1)and 1573 mAh·cm^(-3),respectively.After 200 cycles,the 95%capacity could be retained compared with that upon the 2nd cycle at 0.5 A·g^(-1).And the rod morphology was well kept,except that the diameter of the rod was 3 times larger than its original size after the cell was discharged into 0.01 V.
