ZIF-67掺杂纸基锂离子电池隔膜的制备及其性能研究

Preparation and Properties of ZIF-67 Doped Paper-based Separator for Lithium-ion Batteries

关键词:  纸基电池隔膜  剑麻纤维  ZIF-67  羧甲基化  电化学性能

Key Words:paper-based separator  sisal fiber  ZIF-67  carboxymethylation  electrochemical properties

摘要:本研究将二甲基咪唑钴（ZIF-67）添加到剑麻浆料中，抽滤后制备ZIF-67掺杂纸基锂离子电池隔膜。结果表明，随着ZIF-67掺杂量由0增加至30%，纸基锂离子电池隔膜的孔隙率由74.5%降至45.5%，亲液性增加，离子电导率由0.29 mS/cm提高至2.58 mS/cm，界面电阻由467 Ω减小至210 Ω，电化学稳定窗口由4.6 V增加至5.2 V。当ZIF-67掺杂量为30%时，组装的锂离子电池在循环50次后容量保持率高达90%。剑麻纤维经羧甲基化改性后，纸基锂离子电池隔膜的孔隙率增加，各项电化学性能也有所提高，但由于其机械强度较差，导致其电池容量快速衰减。

Abstract:In the study， cobalt 2-methylimidazole （ZIF-67） was added into sisal pulp followed by filtration and then produced to ZIF-67 doped paper-based separator for lithium-ion batteries（LIBs）. The results showed that the porosity of paper-based separators for LIBs decreased from 74.5% to 45.5% with the increase of the ZIF-67 dosage from 0 to 30%， and the affinity of separators to liquid electrolyte enhanced， ionic conductivity increased from 0.29 mS/cm to 2.58 mS/cm， interfacial resistance decreased from 467 Ω to 210 Ω， and electrochemical stability window increased from 4.6 V to 5.2 V. When the doping content of ZIF-67 was 30%， the capacity retention rate of assembled LIBs was up to 90% after 50 cycles. When the sisal fibers were modified by carboxymethylation， the porosity of the paper-based separators for LIBs increased， and the electrochemical properties were also improved. However， the capacity of the separators rapidly decreased due to its poor mechanical strength.