Fibrous Network of C@MoS2 Nanocapsule-Decorated Cotton Linters Interconnected by Bacterial Cellulose for Lithium- and Sodium-Ion Batteries.

Abstract

To protect the structure of MoS2 from collapse, a strong skeleton is expected to help maintain the integrity. In this study, cotton linters burdened with hollow C@MoS2 nanocapsules are added into nutrient medium for the growth of a bacterial cellulose membrane. Benefitting from good conductivity and structural integrity, the resultant fibrous membrane anode gives reversible capacities of 559 and 155 mAh g-1 for Li-ion batteries and Na-ion batteries after 100 cycles, respectively. The structural transformation and component evolution in lithiation-delithiation and sodiation-desodiation was elucidated by in situ Raman spectroscopy. After sodiation, the Na2 S did not transform back into MoS2 but was more likely converted into elemental sulfur during the conversion reaction. Layered semiconducting transition metal chalcogenides, such as molybdenum disulfide (MoS2 ), feature open 2 D ion-transport channels amenable to receive various guest ions with high theoretical capacities.[2] One serious challenge curtailing the applicability of such materials is their volume changes during discharge-charge processes.[3, 4] However, particular morphologies of MoS2 are proposed to improve the specific capacity.[5,6,7] Many works have focused on core-shell and hollow MoS2 micro- and nanostructures, and the results validate the advantages of shortening the lithium-ion diffusion distance and enhancing specific capacity.[8,9] Unfortunately, the issue of inferior capacity stability is not resolved, because the structure is not effectively protected and is prone to collapse.