Dense-Stacking Porous Conjugated Polymer as Reactive-Type Host for High-Performance Lithium Sulfur Batteries

Xiaowei Wang; Yangyuchen Yang; Chen Lai; Runlai Li; Haomin Xu; Darren H S Tan; Kun Zhang; Wei Yu; Oeystein Fjeldberg; Ming Lin; Wei Tang; Ying Shirley Meng; Kian Ping Loh

doi:10.1002/anie.202016240

Dense-Stacking Porous Conjugated Polymer as Reactive-Type Host for High-Performance Lithium Sulfur Batteries

Angew Chem Int Ed Engl. 2021 May 10;60(20):11359-11369. doi: 10.1002/anie.202016240. Epub 2021 Apr 6.

Authors

Xiaowei Wang^{1

2}, Yangyuchen Yang³, Chen Lai⁴, Runlai Li¹, Haomin Xu^{1

5}, Darren H S Tan⁶, Kun Zhang¹, Wei Yu¹, Oeystein Fjeldberg⁶, Ming Lin⁵, Wei Tang⁴, Ying Shirley Meng^{6

3}, Kian Ping Loh¹

Affiliations

¹ Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore.
² NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 21 Lower Kent Ridge Road, 119077, Singapore, Singapore.
³ Materials Science and Engineering, University of California San Diego, La Jolla, CA, 92121, USA.
⁴ School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shannxi, China.
⁵ Institute of Materials Research and Engineering, A*STAR, 2 Fusionopolis Way, Innovis, 138634 Singapore, Singapore.
⁶ Department of NanoEngineering, University of California San Diego, La Jolla, CA, 92093, USA.

PMID: 33751750
DOI: 10.1002/anie.202016240

Abstract

Commercialization of the lithium-sulfur battery is hampered by bottlenecks like low sulfur loading, high cathode porosity, uncontrollable Li₂ S_x deposition and sluggish kinetics of Li₂ S activation. Herein, we developed a densely stacked redox-active hexaazatrinaphthylene (HATN) polymer with a surface area of 302 m² g^-1 and a very high bulk density of ca. 1.60 g cm^-3 . Uniquely, HATN polymer has a similar redox potential window to S, which facilitates the binding of Li₂ S_x and its transformation chemistry within the bulky polymer host, leading to fast Li₂ S/S kinetics. The compact polymer/S electrode presents a high sulfur loading of ca. 15 mg_s cm^-2 (200-μm thickness) with a low cathode porosity of 41 %. It delivers a high areal capacity of ca. 14 mAh cm^-2 and good cycling stability (200 cycles) at electrolyte-sulfur (E/S) ratio of 5 μL mg_s ^-1 . The assembled pouch cell delivers a cell-level high energy density of 303 Wh kg^-1 and 392 Wh L^-1 .

Keywords: bulky host; dense stacking; high areal capacity; high practical energy density; redox-induced polysulfide deposition.

Abstract

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