Single Atom Array Mimic on Ultrathin MOF Nanosheets Boosts the Safety and Life of Lithium-Sulfur Batteries

Yiju Li; Shuangyan Lin; Dandan Wang; Tingting Gao; Jianwei Song; Peng Zhou; Zhikun Xu; Zhenghao Yang; Ni Xiao; Shaojun Guo

doi:10.1002/adma.201906722

Single Atom Array Mimic on Ultrathin MOF Nanosheets Boosts the Safety and Life of Lithium-Sulfur Batteries

Adv Mater. 2020 Feb;32(8):e1906722. doi: 10.1002/adma.201906722. Epub 2020 Jan 19.

Authors

Yiju Li^{1

2}, Shuangyan Lin³, Dandan Wang⁴, Tingting Gao⁵, Jianwei Song⁶, Peng Zhou¹, Zhikun Xu³, Zhenghao Yang¹, Ni Xiao¹, Shaojun Guo^{1

2}

Affiliations

¹ Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, P. R. China.
² BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, P. R. China.
³ Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, P. R. China.
⁴ Key Laboratory of Functional Materials Physics and Chemistry, Ministry of Education, College of Physics, Jilin Normal University, Siping, 136000, P. R. China.
⁵ Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, 201620, P. R. China.
⁶ State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an, 710049, P. R. China.

PMID: 31957092
DOI: 10.1002/adma.201906722

Abstract

The development of Li-S batteries is largely impeded by the growth of Li dendrites and polysulfide shuttling. To solve these two problems simultaneously, herein the study reports a "single atom array mimic" on ultrathin metal organic framework (MOF) nanosheet-based bifunctional separator for achieving the highly safe and long life Li-S batteries. In the designed separator, the periodically arranged cobalt atoms coordinated with oxygen atoms (CoO₄ moieties) exposed on the surface of ultrathin MOF nanosheets, "single atom array mimic", can greatly homogenize Li ion flux through the strong Li ion adsorption with O atoms at the interface between anode and separator, leading to stable Li striping/plating. Meantime, at the cathode side, the Co single atom array mimic serves as "traps" to suppress polysulfide shuttling by Lewis acid-base interaction. As a result, the Li-S coin cells with the bifunctional separator exhibit a long cycle life with an ultralow capacity decay of 0.07% per cycle over 600 cycles. Even with a high sulfur loading of 7.8 mg cm^-2 , an areal capacity of 5.0 mAh cm^-2 can be remained after 200 cycles. Moreover, the assembled Li-S pouch cell displays stable cycling performance under various bending angles, demonstrating the potential for practical applications.

Keywords: chemical adsorption; lithium anodes; lithium-sulfur batteries; metal-organic framework; separators.

Abstract

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