用于锂离子电池的四嗪环连接的共轭微孔聚合物电极性能研究

Tetrazine-Linked Conjugated Microporous Polymers as Anode Materials for Li-Ion Battery

共轭微孔聚合物因其交联多孔的骨架及高度共轭的结构,在锂离子电池电极材料领域具有巨大的应用前景。以四嗪作为连接单元,构筑了具有氧化还原活性的共轭微孔聚合物TZF和TBFZ,并对该共轭微孔聚合物作为锂离子电池负极材料的性能进行了测试。结果表明,由于具有更丰富的活性单元四嗪环以及更低的最低未占分子轨道能级,TZF展现出比TBFZ更好的电化学性能。此外,在不同的电流密度下循环后,TZF比容量均有不同程度的提高。当电流密度为0.1C时,循环250次后比充电容量从62增加到108.6 mAh·g^(-1);电流密度为1.0C时,循环1000次后比充电容量从40提高到139 mAh·g^(-1),并且库伦效率始终接近100%,表明TZF作为锂离子电池负极材料具有良好的氧化还原活性及循环稳定性。

Conjugated microporous polymers exhibit great application prospects in lithium-ion battery electrode materials due to the cross-linked porous skeleton and highly conjugated structure.In this work,redox-active conjugated microporous polymers TZF and TBFZ were prepared by using tetrazine as the linking units,and their performances as anode materials for Li-ion batteries were tested.The results show that TZF exhibits better electrochemical performance than TBFZ owing to the richer active unit tetrazine ring and lower LUMO energy level of TZF.In addition,the specific capacity of TZF is improved in different degrees after cycling at various C-rates.The specific charge capacity increases from 62 to 108.6 mAh·g^(-1)after 250 cycles at 0.1C,when the charge and discharge rate raises to 1.0C,the capacity increases from 40 up to 139 mAh·g^(-1)after 1000 cycles,and its coulombic efficiency is always close to 100%,indicating that TZF as an anode material for lithium-ion batteries exhibits good redox activity,good rate performance and cycle stability.