Noncombustible 7 µm-thick solid polymer electrolyte for highly energy density solid state lithium batteries

• Published in: Nano energy Vol. 112; p. 108448
• Main Authors: Han, Longfei, Liu, Yongyu, Liao, Can, Zhao, Yonghui, Cao, Yukun, Kan, Yongchun, Zhu, Jixin, Hu, Yuan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2023
• Subjects: NH4PF6; PA6 nanofiber; PEO polymer electrolyte; Safe solid electrolyte; PEO polymer electrolyte; PA6 nanofiber; Safe solid electrolyte; NH4PF6
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2023.108448

Solid polymer electrolytes have attracted significant attention due to their outstanding properties. Determining how to further improve the energy density, ionic conductivity and safety of batteries is key to industrialization. Here, we prepared an ultra-thin, highly safe PEO/LiTFSI/3% NH4PF6 @PA6 polymer solid electrolyte. Compared with conventional electrolytes, this polymer electrolyte can be up to 7 µm thick, leading to lower cell impedance and higher energy density. The Li//PEO/LiTFSI/3% NH4PF6 @PA6//Li cell can cycle for more than 2000 h at 60 °C. Besides, PEO-based electrolytes with only 3 wt% addition of NH4PF6 exhibits high fire safety. The pouch cell assembled using this electrolyte does not short-circuit under bending and cutting and does not burn even in a thermal runaway test. [Display omitted] •Low addition of high efficiency flame retardants (3 wt% NH4PF6) can make the polymer electrolyte noncombustible.•Mechanism of PA6 nanofibers film improving the electrochemistry performance of the ultra-thin polymer electrolyte is analyzed.•The simulation and experiments are shown the inhibition effect of high mechanical strength polymer electrolyte on lithium dendrite.•A new instrument is designed to monitor the heat, temperature, gas composition changes of battery during testing.•The flame-retardant mechanism of the polymer electrolyte is analyzed by the combination of various instruments.