木材基凝胶聚合物电解质的制备及其性能研究

Preparation and Properties of Wood-based Gel Polymer Electrolyte

关键词:  轻木  凝胶聚合物电解质  锂离子电池  电化学性能

Key Words:balsa wood  gel polymer electrolyte  lithium-ion battery  electrochemical properties

摘要:本研究以轻木为原料，经碱处理、漂白、乙酰化、热压和浸渍电解液制备出一种新型木材基凝胶聚合物电解质（GPE）。结果表明，热压改性木片的结晶度为54.7%，机械强度为2.16 MPa，热稳定性高达300 ℃。经电解液润胀后，热压改性木片的孔隙率和吸液率分别为74.6%和719.0%，与热压前性能一致。同时，木材基GPE展现出优异的离子电导率（3.68 mS/cm）和电化学稳定窗口（5.0 V）。组装的Li/GPE/LiFePO₄锂离子电池在0.5 C下循环100圈后的容量由150.9 mAh/g仅衰减至146.1 mAh/g。但由于木材基GPE的孔径大，组装的锂离子电池的库伦效率仅为91%。

Abstract:In this study， balsa wood was used to prepare a novel wood-based gel polymer electrolyte （GPE） via alkali treatment， bleaching， acetylation， hot-pressing， and immersion of liquid electrolyte. The results showed that the crystallinity， mechanical strength， and thermal stability of hot-pressed modified wood was 54.7%， 2.16 MPa， and 300 ℃， respectively. After immersion of liquid electrolyte， the porosity and electrolyte uptake of modified wood were 74.6% and 719.0%， respectively， which were consistent with that before hot-pressing. Furthermore， the wood-based GPE exhibited good ionic conductivity （3.68 mS/cm） and wide electrochemical stability window （5.0 V）. The capacity of assembled Li/GPE/LiFePO₄ lithium-ion battery decayed from 150.9 mAh/g to 146.1 mAh/g at a rate of 0.5 C after 100 cycles. However， due to the large pore size of the wood-based gel polymer electrolyte， the coulombic efficiency of the assembled lithium-ion battery was only 91%.