Research on the Preparation of High Nitrogen-Doped Anode Materials and Their Low-Temperature Performance

Abstract

Electrode materials are crucial factors influencing the low-temperature performance of lithium-ion batteries. On the anode side, the diffusion of lithium ions in graphite anodes is one of the significant bottlenecks restricting the low-temperature performance of lithium batteries. Compared with graphite materials, amorphous carbon materials possess good ion diffusion properties and are a preferred type of anode materials for low-temperature lithium-ion batteries. In this paper, high nitrogen-doped amorphous carbon materials were obtained through the carbonization of g-C₃N₄ assisted by asphalt. The synergistic system of its unique microstructure and electrochemical properties achieved a dual improvement in low-temperature performance. When the ratio of asphalt to g-C₃N₄ was 1:1, the prepared amorphous carbon material had a high nitrogen doping content (9.33%), a relatively large specific surface area (106.38 m²/g), and abundant pore volume (0.295 cm³/g). At a current density of 0.2 C, the specific discharge capacities at test temperatures of -20 °C, -40 °C and -60 °C reached 288, 235 and 161 mAh/g respectively. This dual-carbon composite material with nitrogen doping in amorphous carbon significantly improves the low-temperature performance of lithium-ion batteries and provides an effective solution for the development of the application of amorphous carbon in low-temperature lithium-ion batteries.

Keywords: electrode material, low-temperature performance, amorphous carbon materials, nitrogen doping, dual-carbon composite material