Benzene-1, 2-dithiolato complexes as cathode materials for rechargeable lithium batteries. (20th February 2021)

• Record Type: Journal Article
• Authors: Li, Fengli; Guo, Wei; Si, Yubing; Li, Zhongjun; Fu, Yongzhu
• Is Part Of: Electrochimica acta. Volume 370(2021)
• Publication Date: 2021-02-20
• Subjects: Organosulfide -- Metal-organic complex -- Benzenedithiol -- Lithium battery; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.137757
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: Benzene-1, 2-dithiolato complexes (M-BDTs) are synthesized and used as cathode materials. The M-BDTs are colored solids and insoluble in liquid ether electrolyte. The volumetric specific capacities and energy densities of M-BDTs are increased. The separate electron/lithium ion storage processes are highly reversible. Abstract: Organosulfides are a class of promising cathode materials for rechargeable lithium batteries. In order to overcome their disadvantages of solubility and low mass density, we prepare benzene-1, 2-dithiolato complexes with metal ions (Sn 4+ and Cu 2+ ) by a facile method, which are designated as Sn-(BDT)2 and Cu-BDT, respectively. The synthesized compounds are colored solids and insoluble in liquid ether electrolyte. Their mass densities are about 2.0 mg cm −3, which are much higher than that (1.2 mg cm −3 ) of the starting material 1, 2-benzenedithiol. When evaluated in Li half cells, Sn-(BDT)2 delivers a capacity of 221.2 mAh g −1 rendering a volumetric energy density of 973.2 Wh L −1 . Cu-BDT can deliver a capacity of 234.2 mAh g −1 and its volumetric energy density is 1044.5 Wh L −1 . Both volumetric capacities and energy densities are higher than those of the starting material. In the discharge, the metal ions serve as electron receptors and 1, 2-benzenedithiolate holds lithium ions. The separate electron/lithium ion storage process is highly reversible, which is evidenced by the cycling performances of 200 and 500 cycles for the Li/Sn-(BDT)2 and Li/Cu-BDT cells, respectively. This strategy is promising to overcome the intrinsic disadvantages of organosulfides as cathode materials for lithium batteries. Graphical abstract: Image, graphical abstract