膨胀碳微球/氧化锡复合材料的制备及其电化学性能

Preparation and electrochemical properties of expanded mesocarbon microbeads/SnO_2 composite

为了提高锂离子电池的能量密度,利用低温氧化-水热法成功制备了锡/碳复合材料,并采用SEM、TEM、XRD和恒流充放电分析表征锡/碳复合材料的性能.结果表明:利用锡/碳复合材料的协同效应能够提升锂离子电池的容量和循环寿命,当锡/碳复合比为1∶1时,复合材料展现出了最优的循环性能,同时保持高的比容量,在220次循环后,电流密度100 m A/g下,电池比容量为550 m Ah/g,容量保持率达到95%以上,远大于石墨理论比容量372 m Ah/g,说明锡/碳复合材料能够有效提高锂离子电池的能量密度,并具有良好的循环性能.

In order to improve the energy density of lithium-ion batteries, the tin/carbon composite was successfully prepared by low temperature oxidation-hydrothermal method. SEM, TEM, X-Ray diffraction （XRD） and galvanostatic charge-discharge experiments were used to characterize the tin/carbon composite. The results show that the synergistic effect of tin/carbon composite can enhance the capacity and cycle life of lithium-ion batteries. When the tin/carbon composite ratio is 1 颐 1, the material exhibits the best cycle performance while maintaining a high capacity, after 220 cycles it delivers the reversible capacity of 550 mAh/g, and the capacity retention of 95% at the current density of 100 mA/g. The capacity is much larger than the graphite theoretical specific capacity of 372 mAh/g. It illustrates that the tin/carbon composite materials can effectively improve the energy density of lithium-ion batteries, and has a good cycle performance.