Electrochemical Performance of N-Doped Graphite @Carbon/ Red Phosphorous Composite for Lithium-Ion Secondary Batteries

Abstract

Lithium-ion batteries (LIBs) are well-known for having three key features: lightweight, extended cycle life, and high energy density. This makes them perfect for various uses like electric cars and portable electronics. Red phosphorus (P) is low-cost, easily available, and possesses an excellent theoretical specific capacity (2596 mAh g⁻¹) for use as the anode material in high-energy–density lithium-ion batteries (LIBs). However, P has poor conductivity (10^–12 Sm⁻¹), and colossal volume expansion during charging-discharging hinders its application in LIBs. Conversely, despite various reported anode materials, graphite remains the commercial choice for lithium-ion batteries. This study presents a nitrogen-doped graphite@carbon anode material composite with P that was designed and fabricated through a simple and scalable process. The nitrogen-doped graphite composite with carbon, NGC, effectively reduces harmful reactions between the electrolyte and graphite, ensuring stable electrode performance during charging and discharging. By incorporating optimized content of high-capacity phosphorus (P), NGC’s capacity and electronic conductivity improve, minimizing volume changes of raw red phosphorus through hybridization with the conductive carbon framework. The best optimized NGC/P2 composite shows a high initial discharge capacity of 1486 mAh g⁻¹ and a reversible capacity of 530 mAh g⁻¹ at a current density of 100 mA g⁻¹ after 100 cycles, outperforming conventional graphite. This highlights innovative strategies for sustainable and efficient energy storage solutions.