硅/碳复合负极极片的退火改性

Annealing modification of silicon/carbon composite anode electrode

通过机械球磨-高温热解法制备硅/碳复合负极材料,对电极进行改性,研究低温退火处理对极片性能的影响。改性前后,材料的结构没有太大的改变,而电极的稳定性得到增强,硅/碳复合材料的电化学性能得到改善。在0.01~2.00V充放电,当电流为100mA/g时,改性前后材料的首次充电比容量分别为743.7mAh/g和712.3mAh/g,首次库仑效率分别为59.2%和62.9%,第50次循环的容量保持率分别为76.5%和85.8%;当电流为200mA/g时,改性后的电极首次可逆比容量为673.3mAh/g,高于改性前电极的466.4mAh/g;第100次循环时,改性后的电极可逆比容量为541.6mAh/g,高于改性前电极的438.8mA/g。

Through the mechanical ball milling combined high temperature pyrolysis technology to prepare silicon(Si)/carbon(C)composite,the effect of low temperature annealing treatment on the performance of the electrode was introduced to improve the electrode performance.The structure of Si/C composite had no obvious change before and after modification,while the stability of the electrode was enhanced and the electrochemical perfonnance of the composite was improved.When chaxged-discharged in 0.01-2.00 V and at a current of 100 mA/g,the initial charge specific capacity of the electrode before and after modification was 743.7 mAh/g and 712.3 mAh/g,respectively,the initial coulomb efficiency was 59.2%and 62.9%Respectively.The capacity retention rates were 76.5%and 85.8%after 50 cycles,respectively.The modified electrode delivered an initial reversible specific capacity of 673.3 mAh/g at 200 mA/g,which was higher than that of before modification(466.4 mAh/g).The modified electrode expressed a reversible specific capacity of 541.6 mA/g after 100 cycles,which was higher than that of before modification(438.8 mAh/g).