Natural Halloysite Nanotubes Coated Commercial Paper or Waste Newspaper as Highly‐Thermal‐Stable Separator for Lithium‐Ion Batteries

Abstract

Commercial polypropylene (PP) and polyethylene (PE) films are widely used as separators for lithium‐ion batteries (LIBs). However, owing to the poor thermal stability of PP and PE films, current LIBs suffer from serious safety risks in their practical applications. As an effective path, the design of novel high‐safety composite separators can significantly overcome the safety issues of LIBs. Herein, a universal and cost‐effective strategy is developed to fabricate highly‐thermal‐stable separators via coating natural halloysite nanotubes (HNTs) on both sides of commercial papers or waste newspaper. The resulted separators show superior properties, including thermal stability, heat conduction, wettability, and electrolyte uptake. Compared with commercial PP separators, both HNTs coated A4 paper and waste newspaper composite separators enable better cycling and rate performance for Li/LiFePO4 cells. Even after burning in fire or treating under 180 °C, the composite separators still present a normal structure, and the assembled cell can perform as regular. Furthermore, the nail penetration test of pouch cells illustrates that such separator significantly prevents thermal runaway of LIBs. The inexpensive and environmentally friendly materials with a facile coating process provide a highly‐thermal‐stable separator for commercial LIBs.

Eco-Friendly Lithium Separators: A Frontier Exploration of Cellulose-Based Materials

“…This separator exhibits better liquid absorption, interface stability, and ion conductivity. Similarly, Huang et al developed a universal and cost-effective strategy to manufacture a highly thermally stable separator by coating natural halloysite nanotubes (HNTs) on both sides of commercial paper or waste newspapers [168]. The obtained separator presented excellent performance, including thermal stability, thermal conductivity, wettability, and electrolyte absorption.…”

Development of composite separators by coating hydrochloric acid-treated halloysite nanotubes on polypropylene separators for lithium-ion batteries

“…Xie et al 20 coated HNTs on both sides of a PP separator to prepare a HNTs@PP separator, and the three-dimensional space structures and one-dimensional channels of HNTs promoted the transport of lithium ions and improved the cycle and rate performance. To test the universality of the action of HNTs, Huang et al 21 developed a highly thermally stable separator by coating HNTs on both sides of commercial papers or waste newspaper. Xu et al 22 prepared HNT/PVDF composite separators by a phase inversion method, which showed excellent electrolyte uptake and low interfacial impedance.…”