In Situ Separator Modification with an N-Rich Conjugated Microporous Polymer for the Effective Suppression of Polysulfide Shuttle and Li Dendrite Growth

Yanfei Yang; Peng Mu; Bucheng Li; An Li; Junping Zhang

doi:10.1021/acsami.2c15812

In Situ Separator Modification with an N-Rich Conjugated Microporous Polymer for the Effective Suppression of Polysulfide Shuttle and Li Dendrite Growth

ACS Appl Mater Interfaces. 2022 Nov 2;14(43):49224-49232. doi: 10.1021/acsami.2c15812. Epub 2022 Oct 19.

Authors

Yanfei Yang¹, Peng Mu², Bucheng Li¹, An Li³, Junping Zhang¹

Affiliations

¹ Center of Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 730000Lanzhou, P. R. China.
² College of Chemistry and Chemical Engineering, Northwest Normal University, 730070Lanzhou, P. R. China.
³ Department of Chemical Engineering, College of Petrochemical Engineering, Lanzhou University of Technology, 730050Lanzhou, P. R. China.

PMID: 36260419
DOI: 10.1021/acsami.2c15812

Abstract

Lithium-sulfur (Li-S) batteries are very promising high-energy-density electrochemical energy storage devices, but suffer from serious Li polysulfide (LiPS) shuttle and uncontrollable Li dendrite growth. Here, we show in situ polyolefin separator modification with an N-rich conjugated microporous polymer (NCMP) for advanced Li-S battery. In situ polymerization generates an ultrathin NCMP coating on the whole external surface and the internal surface of the separator, which is substantially different from the conventional approaches with thick coatings only on the external surface. The NCMP coating with abundant N-containing groups (-NH₂ and -N═), uniform nanopores (12.294 Å), and π-conjugated structure can simultaneously inhibit LiPS shuttle and regulate uniform nucleation and growth of Li dendrites. Consequently, the NCMP-based separator endows the Li-S battery with significantly enhanced cycling stability at high S loading (5.4 mg cm^-2), lean electrolyte (E/S = 6.3 μL mg^-1), and limited Li excess (50 μm).

Keywords: Li−S batteries; conjugated microporous polymer; polymerization; separator; surface chemistry.