TCNQ-derived N/S dual-doped carbon cube electrocatalysts with built-in CoS₂ nanoparticles for high-rate lithium-oxygen batteries

Nitrogen/Sulfur dual-doped carbon cubes with built-in CoS₂ nanoparticles (CoS₂@NS-C cubes) as an electrocatalyst are developed to improve the high-rate and long-term performance of lithium-oxygen batteries. The CoS₂@NS-C cubes were synthesized by coprecipitation between a cobalt salt and 7,7,8,8-tetracyanoquinodimethane (TCNQ) and subsequent thermal sulfidation. TCNQ acted as the coordination polymer for a cube shape and as the nitrogen source for nitrogen-dopants. The CoS₂@NS-C cubes comprise uniformly distributed CoS₂ nanoparticles in a nitrogen/sulfur dual-doped carbon matrix, providing fast catalytic activity for oxygen reduction/evolution reactions. The CoS₂@NS-C cubes exhibited a high-rate performance of 5000 mA g⁻¹ as well as long-term performance of > 100 cycles with a current density of 2000 mA g⁻¹. These results confirmed the enhanced performance of the lithium-oxygen battery, with fast charging capability.