Related Experiment Video
Updated: Jun 25, 2025

Preparation of Graphene Liquid Cells for the Observation of Lithium-ion Battery Material
Published on: February 5, 2019
Development of composite separators by coating hydrochloric acid-treated halloysite nanotubes on polypropylene
Qinting Deng1, Xiuyun Chuan1, Yupeng Zhao1
1Key Laboratory of Orogen Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University Beijing 100871 China xychuan@pku.edu.cn.
Abstract:
In this study, polypropylene/halloysite nanotube (PP/HNT) composite separators were prepared by coating HNTs treated with hydrochloric acid (HCl) of different concentrations on both sides of a PP separator. The effect of HNTs treated with hydrochloric acid (HCl) of different concentrations on the properties of PP/HNT composite separators was investigated. The results indicate that the PP/HNT composite separator exhibits higher electrolyte uptake and wettability than a commercial PP separator, resulting in a better electrochemical performance in Li/LiFePO4 cells. In particular, the PP/HNTs-1.2 M composite separator with HNTs treated with 1.2 M HCl exhibits the highest electrolyte uptake (384%) and ionic conductivity (1.03 mS cm-1). The cells assembled with a PP/HNTs-1.2 M composite separator deliver discharge capacities of 166 mA h g-1 (0.5 C) and 131 mA h g-1 (3 C) with attractive cycling performance (87.6% capacity retention after 100 cycles). HNTs treated with HCl of appropriate concentrations can significantly improve the properties of PP/HNT composite separators for application in lithium-ion batteries.

