Nd2O3/KB-coated separator constructs adsorption-catalytic bifunctional framework to improve lithium-sulfur battery performance

Abstract

Lithium-sulfur batteries (LSBs) represent an innovative type of secondary battery poised to surpass lithium-ion batteries owing to the exceptionally high theoretical specific capacity. However, widespread adoption faces challenges such as reduced Coulombic efficiency from the shuttle effect and poor conductivity of Li₂S₂/Li₂S. These challenges can potentially be addressed effectively by using functional separator layers. In this work, we designed a novel PP separator with a coating of Nd₂O₃-doped Ketjen Black (Nd₂O₃/KB/PP). Nd₂O₃ contributes to chemical adsorption and catalytic conversion, while KB enhances physical adsorption. Together, these components form an adsorption-catalytic bifunctional framework network. The experimental results demonstrate that Nd₂O₃/KB/PP significantly improves the performance of LSBs. At 2 C, the specific discharge capacity reaches 861 mAh/g initially, with an average decay rate of only 0.043% per cycle. Additionally, with a high sulfur load of 5.8 mg/cm², the initial area specific capacity was 5.5 mAh/cm², with 4.1 mAh/cm² remaining after 100 cycles at 0.1 C. This research contributes valuable insights toward advancing the commercial viability of LSBs.