“Three‐in‐one” strategy: Heat regulation and conversion enhancement of a multifunctional separator for safer lithium–sulfur batteries
Kaiping Zhu,
Luhe Li,
Pan Xue,
Jun Pu,
Liyun Wu,
Gengde Guo,
Ran Wang,
Ye Zhang,
Huisheng Peng,
Guo Hong,
Qiang Zhang,
Yagang Yao
Affiliations
Kaiping Zhu
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China
Luhe Li
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China
Pan Xue
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China
Jun Pu
Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science Anhui Normal University Wuhu China
Liyun Wu
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China
Gengde Guo
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China
Ran Wang
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China
Ye Zhang
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China
Huisheng Peng
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Laboratory of Advanced Materials Fudan University Shanghai China
Guo Hong
Department of Materials Science and Engineering, College of Engineering City University of Hong Kong Hong Kong China
Qiang Zhang
Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering Tsinghua University Beijing China
Yagang Yao
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China
Abstract The safety problems encountered with lithium–sulfur batteries (LSBs) hinder their development for practical applications. Herein, a highly thermally conductive separator was constructed by cross‐weaving super‐aligned carbon nanotubes (SA‐C) on super‐aligned boron nitride@carbon nanotubes (SA‐BC) to create a composite film (SA‐BC/SA‐C). This separator was used to fabricate safe LSBs with improved electrochemical performance. The highly aligned separator structure created a uniform thermal field that could rapidly dissipate heat accumulated during continuous operation due to internal resistance, which prevented the development of extremely high temperatures. The array of boron nitride nanosheets endowed the composite separator with a large number of adsorption sites, while the highly graphitized carbon nanotube skeleton accelerated the catalytic conversion of high‐valence polysulfides into low‐valence polysulfides. The arrayed molecular brush design enabled the regulation of local current density and ion flux, and considerably alleviated the growth of lithium dendrites, thus promoting the smooth deposition of Li metal. Consequently, a battery constructed with the SA‐BC/SA‐C separator showed a good discharge capacity of 685.2 mAh g−1 over 300 cycles (a capacity decay of 0.026% per cycle) at 2 C and 60°C. This “three‐in‐one” multifunctional separator design strategy constitutes a new path forward for overcoming the safety problems of LSBs.
