Preferential lattice expansion of polypropylene in a trilayer polypropylene/polyethylene/polypropylene microporous separator in Li-ion batteries.

ABSTRACT: The abnormal lattice expansion of commercial polypropylene (PP)/polyethylene (PE)/polypropylene (PP) separator in lithium-ion battery under different charging current densities was observed by in-situ X-ray diffraction. Significant lattice changes of both PP and PE were found during the low current density charging. The capacity fading and the resistance value of the cell measured at 0.025 C (5th retention, 92%) is unexpectedly larger than that at 1.0 C (5th retention, 97.3%) from the electrochemical impedance spectroscopic data. High-resolution scanning electron microscopy is employed to witness the pore changes of the trilayered membrane. Density functional theory calculations were used to investigate the mechanism responsible for the irregular results. The calculations revealed that the

SUBMITTER: Hsu WD 

PROVIDER: S-EPMC7820226 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature