Wang Zhiyan, Ma Junfeng, Cui Ping, Yao Xiayin
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, P. R. China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
ACS Appl Mater Interfaces. 2022 Aug 3;14(30):34649-34655. doi: 10.1021/acsami.2c06204. Epub 2022 Jul 19.
A flexible poly(vinylidene fluoride)-polyetherimide@poly(ethylene glycol) (PVDF-PEI@PEG) solid composite polymer electrolyte is prepared by an thermal curing approach. The homogeneous PVDF-PEI composite porous membrane with an optimized PVDF and PEI weight ratio increases the amorphous phase, while the fast lithium ion transport channels are formed through the filled PEG electrolytes. The optimized polymer electrolyte exhibits high ionic conductivity of 2.36 × 10 S cm at 60 °C and lithium ion transference number of 0.578 as well as excellent electrochemical stability window of 5.5 V. Moreover, the superior stability toward lithium metal anode enables over 3600 h cycling of the Li//Li symmetric cell at 0.1 mA cm. In particular, the LiFePO//Li battery delivers high specific capacities of 132.4 and 111.5 mAh g with a retention of 86.6% and 85.9% after 200 cycles at 2 C and 100 cycles at 3 C rate under 60 °C, respectively, demonstrating the feasibility as an energy storage device with high rate capability.
通过热固化方法制备了一种柔性聚偏氟乙烯-聚醚酰亚胺@聚乙二醇（PVDF-PEI@PEG）固体复合聚合物电解质。具有优化的PVDF和PEI重量比的均匀PVDF-PEI复合多孔膜增加了非晶相，同时通过填充的PEG电解质形成了快速锂离子传输通道。优化后的聚合物电解质在60℃时表现出2.36×10 S cm的高离子电导率、0.578的锂离子迁移数以及5.5 V的优异电化学稳定窗口。此外，对锂金属负极的优异稳定性使Li//Li对称电池在0.1 mA cm下能够循环超过3600 h。特别是，LiFePO//Li电池在60℃下以2 C倍率循环200次和以3 C倍率循环100次后，分别具有132.4和111.5 mAh g的高比容量，保留率分别为86.6%和85.9%，证明了其作为具有高倍率性能的储能装置的可行性。
