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Updated: Aug 5, 2026
07:23
Construction and Testing of Coin Cells of Lithium Ion Batteries
Published on: August 2, 2012
Janus Bilayer Separator With Opposite Charges for Lithium Metal Batteries
Xiaoyu Chen1, Yufei Yang1, Xiangyu Li1
1Key Laboratory of Material Chemistry For Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Ministry of Education, Huazhong University of Science and Technology, Wuhan, China.
Small (Weinheim an Der Bergstrasse, Germany)
|July 27, 2026
Summary
A novel Janus bilayer separator with opposing charges enhances lithium ion transport and prevents dendrite growth in lithium metal batteries (LMBs). This design boosts battery stability and safety for improved performance.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- Uncontrolled lithium ion transport and dendrite formation are critical issues affecting the stability and safety of lithium metal batteries (LMBs).
- Existing separators often struggle to balance ion conductivity with dendrite suppression, limiting battery performance and lifespan.
Purpose of the Study:
- To design and investigate a novel Janus bilayer separator with tailored ionic properties to enhance lithium ion transport and suppress dendrite growth in LMBs.
- To improve the cycling stability, safety, and overall performance of lithium metal batteries through advanced separator engineering.
Main Methods:
- Fabrication of a Janus bilayer separator comprising a sulfonated aramid nanofiber (S-ANF) layer and a quaternary ammonium-functionalized covalent organic framework (N-COF) layer.
- Characterization of the separator's ionic conductivity, lithium ion transference number, thermal stability, and electrochemical performance in Li||LiFePO4 and Li||Li symmetric cells.
Main Results:
- The S-ANF/N-COF separator exhibited a high lithium ion transference number (0.67) and enhanced ionic conductivity (1.39 mS cm⁻¹).
- The separator demonstrated exceptional thermal stability and suppressed lithium dendrite growth, enabling stable lithium plating/stripping for over 600 hours in symmetric cells.
- Li||LiFePO4 cells assembled with the S-ANF/N-COF separator achieved 72.6% capacity retention after 3000 cycles at 5C and 86.3% at 70°C after 100 cycles, outperforming conventional separators.
Conclusions:
- The developed Janus bilayer separator effectively regulates ion transport and suppresses dendrite growth, significantly enhancing the stability and safety of lithium metal batteries.
- This ion-regulated separator design strategy offers a promising approach for developing next-generation high-performance and safe lithium metal batteries.
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