The “dual-layer sulfur cathode” strategy: An In2S3/Bi2S3@rGO heterostructure as an interlayer/modified separator for boosting the areal capacities of lithium-sulfur batteries

• Published in: Journal of colloid and interface science Vol. 654; pp. 753 - 763
• Main Authors: Al-Tahan, Mohammed A., Miao, Baoji, Xu, Sankui, Cao, Yange, Hou, Mengyao, Shatat, Mohamed R., Asad, Muhammad, Luo, Yanwei, Shrshr, Aml E., Zhang, Jianmin
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.01.2024
• Subjects: Bimetal sulfide; Dual-layer cathode; Electrocatalyst; Lithium–sulfur battery; Polysulfide; Polysulfide; Dual-layer cathode; Bimetal sulfide; Electrocatalyst; Lithium–sulfur battery
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2023.10.081

The strategy of the Li-S cell with a dual-layer sulfur cathode (integrated thin layer of In2S3/Bi2S3@rGO between two thick-layer of sulfur) coupled with a coated layer on the separator could stop the shuttle effect happening on the bottom layer of sulfur and adsorb the polysulfide from the face side of the upper layer of sulfur. [Display omitted] The specific energies and energy densities of lithium–sulfur (Li-S) batteries are influenced by various cell parameters, including the sulfur loading, the sulfur weight percentage in the cathode, and the electrolyte/sulfur ratio. An In2S3/Bi2S3@rGO heterostructure was obtained by growing indium sulfide nanoparticles on the surface of bismuth sulfide nanoflowers in a graphene oxide (GO) solution via a one-step solvothermal approach. This structure was introduced as a modified separator/dual-layer sulfur cathode for Li-S batteries. The Bi2S3/In2S3 heterointerfaces act as active sites to speed up interfacial electron transfer, along with the entrapment, diffusion, and transformation of lithium polysulfides. A Li-S cell containing a dual-layer sulfur cathode (thin layer of In2S3/Bi2S3@rGO sandwiched between two thick layers of sulfur) and coupled with an In2S3/Bi2S3@rGO-coated separator suppressed the polysulfide shuttle effect. The cell based on the dual-layer sulfur cathode technology and operated at a current rate of 0.3C achieved a high capacity (7.1 mAh cm−2) after the 200th cycle, giving an electrolyte/sulfur ratio (10 µL mg−1) under a high sulfur loading (11.53 mg cm−2). These results demonstrate the unique nature of the dual-layer sulfur cathode technique, which can yield high energy density Li-S batteries with high sulfur loadings and low electrolyte/sulfur ratios.