Design and Construction of Sodium Polysulfides Defense System for Room-Temperature Na-S Battery

Tingting Yang; Bingshu Guo; Wenyan Du; Muhammad Kashif Aslam; Mengli Tao; Wei Zhong; Yuming Chen; Shu-Juan Bao; Xuan Zhang; Maowen Xu

doi:10.1002/advs.201901557

Design and Construction of Sodium Polysulfides Defense System for Room-Temperature Na-S Battery

Adv Sci (Weinh). 2019 Sep 30;6(23):1901557. doi: 10.1002/advs.201901557. eCollection 2019 Dec.

Authors

Affiliations

¹ Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University) Ministry of Education School of Materials and Energy Southwest University Chongqing 400715 P. R. China.
² Department of Nuclear Science and Engineering Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA.
³ Department of Materials Engineering KU Leuven Leuven 3001 Belgium.

Abstract

Room-temperature Na-S batteries are facing one of the most serious challenges of charge/discharge with long cycling stability due to the severe shuttle effect and volume expansion. Herein, a sodium polysulfides defense system is presented by designing and constructing the cathode-separator double barriers. In this strategy, the hollow carbon spheres are decorated with MoS₂ (HCS/MoS₂) as the S carrier (S@HCS/MoS₂). Meanwhile, the HCS/MoS₂ composite is uniformly coated on the surface of the glass fiber as the separator. During the discharge process, the MoS₂ can adsorb soluble polysulfides (NaPSs) intermediates and the hollow carbon spheres can improve the conductivity of S as well as act as the reservoir for electrolyte and NaPSs, inhibiting them from entering the anode to make Na deteriorate. As a result, the cathode-separator group applied to room-temperature Na-S battery can enable a capacity of ≈1309 mAh g^-1 at 0.1 C and long cycling life up to 1000 cycles at 1 C. This study provides a novel and effective way to develop durable room-temperature Na-S batteries.

Keywords: HCS/MoS2; defense sodium polysulfides; in situ Raman; room‐temperature Na–S batteries.