聚席夫碱/碳纳米管复合材料的制备及储锂性能

Preparation and lithium storage properties of poly(Schiff base)/carbon nanotubes composites

为解决席夫碱单体在锂离子电池应用中因活性物质溶解而导致的容量降低问题,以对苯二甲醛和对苯二胺为原料,采用一步缩合法制备以C=N键连接的聚席夫碱(PI)。向PI中掺入碳纳米管(CNTs),进一步制备导电性能较强的聚席夫碱/碳纳米管(PI/CNT)复合材料。采用FT-IR,SEM,XRD,TG,XPS及电化学工作站对制备的聚席夫碱材料的成分、结构、微观形貌及电化学性能进行分析。结果表明:加入5%CNTs(质量分数)的PI/CNT-3材料为三维框架结构,表现出优异的电化学性能。PI/CNT-3材料首次放电比容量为209.9 mAh·g^(-1),200次循环后,循环保持率为60.5%;当充放电倍率分别为0.1 C,0.2 C,0.5 C,1 C,0.1 C时,PI/CNT-3电极材料的比容量分别为182.4,150.8,129.8,101.3,156.4 mAh·g^(-1),具有良好的循环稳定性和倍率性能。

In order to solve the problem of capacity reduction of Schiff base monomer in lithium-ion batteries due to the dissolution of active substances,the Schiff base polymer(PI)with C=N bond was prepared by one-step condensation method using p-benzaldehyde and p-phenylenediamine as raw materials.Poly(Schiff base)/carbon nanotubes(PI/CNTs)composites with high conductivity were prepared by doping carbon nanotubes(CNTs).The composition,structure,micro morphology and electrochemical properties of the prepared materials were analyzed by using FT-IR,SEM,XRD,TG,XPS and electrochemical workstation.The results indicate that the PI/CNT material with 5%CNTs(mass fraction)is a three-dimensional frame structure,and shows excellent electrochemical performance.The first specific capacity of PI/CNT-3 material is 209.9 mAh·g^(-1).After 200 cycles,the cycle retention rate is 60.5%.When the rate of charge and discharge is 0.1 C,0.2 C,0.5 C,1 C and 0.1 C,the specific capacity of PI/CNT-3 electrode materials is 182.4,150.8,129.8,101.3 mAh·g^(-1) and 156.4 mAh·g^(-1) respectively,which has good cycle stability and rate performance.