The effect of the heat treatment to Co-N-C derived from ZIF-67 on the electrochemical performance of lithium-sulfur battery

Abstract

The composite of porous carbon obtained from MOFs loading sulfur has been regard as promising candidate for lithium-sulfur batteries cathode material due to the large specific surface area, high porosity, diversity of types, and designable structures large specific surface area, high porosity, diversity of types, and designable structures. However, the production processes of MOFs materials play a pivotal role on the lithium-sulfur batteries performance. Herein, the effect of key process parameters such as heat treatment temperature, heat treatment time, and heat treatment atmosphere on the electrochemical performance of lithium-sulfur batteries were systematically studied. The results show that at a heating rate of 5 ℃·min ^−1 , heat preservation at 900 ℃ for 3 h, and treatment with CO _2 airflow for 1 h, the composite material has the best electrochemical performance. The first discharge specific capacity of the lithium-sulfur battery reached 1060.32 mAh·g ^−1 , and after 50 cycles it reached 614.29 mAh·g ^−1 . This heat treatment research method based on MOFs-derived materials can be used as a reference for related research in other energy storage and conversion fields.

Keywords

• Li-S battery
• MOFs
• heat treatment
• carbon composite