High-performance Li-S batteries enabled by polysulfide-infiltrated free-standing 3D carbon cloth with CeO2 nanorods decoration

Abstract

To achieve scale-up commercialization of Li-S batteries, parasitic shuttle effect, leading to low utilization of active material and fast capacity decay, has to be resolved effectively. Herein, we prepared CeO2 nanorods decorated interwoven 3-D carbon cloth via facile one-step hydrothermal reaction and Li2S6-containing polysulfide as starting material to successfully improve the electrochemical performance of Li-S battery. First, strong chemical interaction toward polysulfides was successfully constructed by polar CeO2 nanorods and numerous oxygen vacancies on their surface acting as efficient polysulfides anchoring sites significantly enhanced the utilization of active material sulfur. Second, interwoven freestanding carbon cloth can considerably enhance redox kinetics through a 3-D interconnected network with abundant long-range electron transfer channels and can significantly improve redox kinetics by easy accessibility to electrolyte and abundant ion transport pathways. Third, the utilization of Li2S6-containing catholyte leads to uniform distribution of active material and improves sulfur utilization. Benefiting from the aforementioned advantages, free-standing 3-D carbon cloth with CeO2 nanorods decoration combined with Li2S6-containing catholyte (CC@CeO2@Li2S6) electrode delivered an initial discharge capacity of 1311 mA h g−1 at 0.2C and approximately 95% of the initial discharge capacity was remained after 100 galvanostatic cycles, manifesting superior capacity retention with minimal capacity fading of 0.050% per cycle.