Nitrogen and Oxygen Dual-Doped Carbon as High-Rate Long-Cycle-Life Anode Materials for Lithium-Ion Batteries

Abstract

Defect-type carbon, doped with nitrogen and oxygen, is synthesized using the high-temperature solid-phase method. X-ray photoelectron spectroscopy analysis reveals the presence of nitrogen, including pyridine nitrogen, pyrrole nitrogen, and graphitized nitrogen, incorporated into the carbon structure. Additionally, oxygen is introduced into carbon, with both CO and CO functionalities are observed. Transmission electron microscopy and scanning electron microscopy indicate that all samples exhibit a morphology of carbon microblocks with localized turbocharged lattice regions. Electrochemical tests demonstrate that the nitrogen- and oxygen-doped carbon microblocks exhibit excellent cycling performance and high rate capacity. Specifically, at current densities of 1 and 2 A g⁻¹, the rate capacity remains at 385.6 and 214.4 mA h g⁻¹, respectively. Furthermore, the discharge capacity at 5 A g⁻¹ remains at 58.3 mA h g⁻¹ on the 3500th cycle. The defects introduced by nitrogen and oxygen doping not only enhance reactivity and electronic conductivity but also improve lithium-ion diffusion dynamics.