High performance all-solid-state lithium-sulfur battery using a Li2S-VGCF nanocomposite. (10th March 2017)

• Record Type: Journal Article
• Authors: Eom, Minyong; Son, Seunghyeon; Park, Chanhwi; Noh, Sungwoo; Nichols, William T.; Shin, Dongwook
• Is Part Of: Electrochimica acta. Volume 230(2017)
• Page Start: 279
• Page End: 284
• Publication Date: 2017-03-10
• Subjects: Solid electrolyte -- Lithium sulfide -- Glass ceramics -- Lithium-sulfur battery -- All-solid-state battery; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.01.155
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: In lithium-sulfur batteries, cyclability is often strongly limited by a high interfacial resistance caused by poor contact between the active material and electron and lithium ion transporting materials. Here, we develop a Li2 S-VGCF (Vapor Grown Carbon Fiber) nanocomposite positive electrode for an all-solid-state lithium-sulfur battery that significantly improves cyclability. The Li2 S-VGCF nanocomposite is prepared by a solution-based technique with subsequent heat-treatment in order to control the formation of Li2 S nanocrystals within the VGCF electron conducting matrix. The small, well-dispersed Li2 S nanocrystals offer a large contact area with the solid electrolyte and electron conducting carbon in the composite cathode. To further improve conductivity, the composite cathode employs a multi-dimensional approach with long 1-D VGCF fibers supporting long distance electron transport and 0-D carbon powder enhancing the contact area with the Li2 S active material at lower total carbon content. In the all-solid-state batteries, the highest initial capacity of 469 mhA∙g −1 is obtained at conditions of 500 °C during heat-treatment. Activation of Li2 S is observed during the first 10 cycles. Subsequently, the capacity gradually increased up to 600 mAh∙g −1 (g of Li2 S). The optimized cell exhibits excellent cyclic performance through 20 cycles and a Coulombic efficiency of ∼100%.