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Nano Research

Article Title

Three-dimensional spongy framework as superlyophilic, strongly absorbing, and electrocatalytic polysulfide reservoir layer for high-rate and long-cycling lithium-sulfur batteries

Authors

Lianbo Ma, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Guoyin Zhu, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Wenjun Zhang, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Peiyang Zhao, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Yi Hu, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Yanrong Wang, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Lei Wang, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Renpeng Chen, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Tao Chen, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Zuoxiu Tie, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
Jie Liu, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China Department of Chemistry, Duke University, Durham, NC 27708, USA
Zhong Jin, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China

Keywords

lithium-sulfur batteries, composite spongy framework, polysulfide reservoir layer, chemisorption and absorbability, electrocatalytic effect

Abstract

ABSTRACT In the development of lithium-sulfur (Li-S) batteries, various approaches have been adopted to enhance the electronic conductivity of the sulfur cathode and alleviate the shuttle effect of polysulfides; however, the strategies providing efficient solutions are still limited. To further improve the electrochemical performance of Li-S batteries, in this work we propose a new strategy involving the incorporation of a three-dimensional functional spongy framework as polysulfide reservoir layer, with strong absorbability and electrocatalytic activity towards sulfur species. The spongy framework has a hierarchical architecture composed of highly conductive Ni foam/graphene/carbon nanotubes/MnO2 nanoflakes (NGCM). The strongly interconnected Ni foam, graphene, and carbon nanotubes of the NGCM sponge facilitate electron transfer during discharge/charge processes; moreover, the superlyophilic properties of the NGCM sponge ensure good wettability and interface contact with the Li-S electrolyte, and the porous MnO2 nanoflakes provide strong chemisorptive and electrocatalytic effects on polysulfides (as confirmed theoretically and experimentally). The NGCM sponge, serving as a polysulfide reservoir layer attached on a conventional sulfur-mixed carbon nanotubes (S/CNTs) cathode, can provide improved reversible capacity, rate capability (593 mAh·g–1 at 3.0 C), and cycling stability. In addition, the self-discharge rate is greatly reduced, owing to the efficient conservation of polysulfides in the NGCM spongy framework.

Graphical Abstract

Publisher

Tsinghua University Press

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