Preparation of Pitch Porous Nitrogen-doped Carbon and Its Low-temperature Lithium Storage Properties

The electrochemical performance of conventional lithium-ion batteries are significantly deteriorates at low temperatures, posing a significant challenge in the development of battery technology. This paper addresses this issue by focusing on the synthesis of a nitrogen-doped porous carbon material with fast lithium-ion diffusion and reaction kinetics at low temperatures. The material was prepared using pitch as a precursor, urea as a nitrogen source and blowing agent, and SiO₂ as a template. The obtained nitrogen-doped porous carbon material (denoted as PN-2) displayed a specific surface area of 167.64 m²/g and approximately five microcrystalline layers when the urea addition was 20%. Notably, at low temperatures, PN-2 demonstrated an impressive discharge specific capacity, with average values of 372, 295, 254, and 197 mAh/g at 25 °C, 0 °C, −20 °C, and −40 °C, respectively. The large specific surface area of the porous carbon material effectively increased the active sites for lithium ions, promoting rapid diffusion and improved lithium/delithium kinetics, thus enhancing the multiplicity performance at low temperatures. This research provides the valuable insights for the design of high-performance lithium-ion battery materials suitable for cold climate environments.