CoSe Nanoparticles Encapsulated by Nitrogen-Enriched Hierarchically Porous Carbon for High-Performance Lithium-Ion Batteries.

Coordination compound derivates (CCDs) have been widely applied in lithium-ion batteries (LIBs). However, the functionalization of CCDs with open structure and heteroatomic doping is still challenging. Herein, an effective functionalization strategy is presented to prepare a kind of CCD, where CoSe nanoparticles are encapsulated by nitrogen-enriched hierarchically porous carbon (CS/NPC) based on the heat treatment of a cobalt-complexed hexamethylolmelamine-polyvinylpyrrolidone resin (Co/HPR). The abundant free volume and enriched N species of the HPR are responsible for the hierarchically porous configuration and high N-doping of the composites. By controlling the content of cobalt salt and the heating rate, high specific surface area (440.7 m g), high N-doping (8.54 atom %), and suitable mass loading of CoSe (55.5%) were simultaneously achieved in CS-2/NPC-5, which delivers high reversible capacity (758.5 mAh g at 0.1 A g), outstanding rate capability (401.7 mAh g at 5 A g), and excellent cycling durability (638.4 mAh g at 1 A g after 200 cycles), suggesting a promising candidate for LIB anode materials.