Li 2 S@C/CNT composite cathode with botryoidal conductive network for advanced lithium–sulfur batteries

Lithium sulfide (Li 2 S) is a promising alternative cathodic material for lithium–sulfur batteries, which can alleviate the volume expansion of sulfur‑based cathodes. As a fully lithiated cathode, Li 2 S can be paired with Li-free anodes, thereby increasing the selectivity of anodic materials. Nevertheless, Li 2 S cathode is hindered by its high cost, harsh preparation conditions, and inadequate conductivity, which impose limitations on its practical application. Hence, the crucial factor in enabling the practicality of Li 2 S cathode is the development of low-cost and facile synthetic methods to produce highly conductive Li 2 S material. Herein, a high‑conductivity Li 2 S@C/CNT composite cathode is prepared using low-cost Li 2 SO 4 as a lithium source through a facile spray drying technique combined with carbothermal reduction method. Benefiting from the high-speed three-dimensional pathway for electron transport provided by the in-situ formed botryoidal highly conductive network, the Li 2 S@C/CNT cathode exhibits ultrahigh initial discharge capacity (1028.5 mA h g − 1 @1 C), superior cycle stability (520.6 mA h g − 1 after 200 cycles), and remarkable rate capability (301.8 mA h g − 1 @5 C). This work not only presents a simple and feasible approach for the low-cost preparation of high‑performance Li 2 S cathode, but also proposes an innovative idea for advancing the development of high energy density lithium–sulfur batteries.