Ultrahigh sulfur content up to 93 wt% encapsulated in multilayer nanoshell of V/V2O5 composite to suppress shuttle effect of lithium–sulfur battery with high-performance. (September 2019)

• Record Type: Journal Article
• Authors: Lin, Jin-Xia; Mo, Yu-Xue; Zhang, Peng-Fang; Li, Yu-Yang; Wu, Yi-Jin; Zhang, Shao-Jian; Gao, Zhen-Guang; Chen, Jian-De; Ren, Wen-Feng; Li, Jun-Tao; Zhou, Yao; Huang, Ling; Sun, Shi-Gang
• Is Part Of: Materials today energy. Volume 13(2019)
• Page Start: 267
• Page End: 276
• Publication Date: 2019-09
• Subjects: Lithium-sulfur batteries -- Ultrahigh sulfur content -- Multilayered porous composite nanoshell -- Chemical adsorption -- Shuttle effect suppression; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2019.05.014
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: Renowned for its high theoretical specific energy, lithium-sulfur (Li–S) batteries still suffer from the shuttle effect of polysulfides, the insulating nature of sulfur and severe volumetric variations, especially for cathodes with high sulfur contents. Herein, S microsphere encapsulated within a thickness-tunable multilayered thin V/V2 O5 nanoshell (S@V/V2 O5 ) was explored as a high-sulfur-content cathode (up to 93 wt%) for Li–S batteries. With a polar V2 O5 moiety the nanoshell could physically block and chemically adsorb polysulfides, while the metallic V could assure efficient electron transfer; this multilayered and porous nanoshell could also buffer the volumetric variations of the sulfur core and facilitate Li + transportation. Such S@V/V2 O5 electrode with a 87 wt% sulfur content delivers high specific capacity (1403 mAh g −1 ) and remarkable areal initial capacity (4.4 mAh cm −2 ) at 0.2 C, excellent cycling stability (819 mAh g −1 at 0.5 C after 300 cycles), superior high-rate capacity (804 mAh g −1 at 4 C), low self-discharge (759 mAh g −1 after resting 50 days) and a high coulombic efficiency above 90% in a LiNO3 -free electrolyte. A current collector-free S@V/V2 O5 cathode with sulfur content of 93 wt% is also achieved, which yields stable discharge capacity of 1000 mAh g −1 at 0.2 C after 100 cycles. Graphical abstract: Image 1 Highlights: Sulfur microsphere was encapsulated in a multilayered V/V2 O5 nanoshell (S@V/V2 O5, 93 wt% S) for Li-S batteries. The V/V2 O5 nanoshell could suppress the shuttle effect and the metallic V could enhance the interfacial conductivity. Thus S@V/V2 O5 cathodes could run stably for 500 cycles at 1 C and exhibit 804 mAh g −1 at 4 C. Low self-discharge of 759 mAh g −1 (rested 50 days) and high specific energy of 2576 Wh kg −1 could be achieved (4.1 mg). Such S@V/V2 O5 cathodes also show excellent performances with a LiNO3 -free electrolyte or without a current collector.