Introduction to High-Temperature and High-Pressure Method of Graphitization Furnace

2025-04-11 14:05:22

The high-temperature and high-pressure method for graphitization in a Graphitization furnace refers to a process that utilizes bituminous coal as a precursor. This involves initial carbonization followed by further high-temperature graphitization treatment at 2000–2800°C to synthesize graphite materials. Research indicates that the microstructure of synthetic graphite materials is strongly dependent on the graphitization temperature. When artificial graphite is graphitized at 2800°C in the furnace, it exhibits a fully ordered layered structure, high graphitization degree, large specific surface area, and well-developed mesopores. These characteristics provide an effective pathway for the electrochemical intercalation-deintercalation of lithium ions within the carbon matrix.

Due to its high-temperature resistance and mechanical strength, graphite is widely used in the metallurgical industry for manufacturing graphite crucibles and furnace linings. Notably, its excellent electrical conductivity makes it a preferred electrode material and a foundational component for composite materials, enabling high-value applications in advanced technological fields. With its high reversible capacity, favorable charge-discharge potential profile, and relatively low cost, graphite is extensively employed in energy storage devices. For instance, after graphitizing petroleum coke at 2600°C in a graphitization furnace, the graphitization degree reaches 78.8%. When used as an anode material in lithium-ion batteries, it delivers a specific discharge capacity of 326.1 mA·h·g⁻¹ and a Coulombic efficiency of 78.8%, demonstrating superior electrochemical performance.

In another study, two types of anthracite with distinct properties were heat-treated within a temperature range of 2400–2800°C in a graphitization furnace to produce graphite, and their electrochemical performance as anodes in lithium-ion batteries was evaluated. The crystal parameters of the graphite materials derived from both anthracites exhibited strong linear correlations. This method enables large-scale graphite production using Acheson furnaces at high temperatures, yielding graphite with satisfactory crystallinity. However, this approach requires temperatures exceeding 2000°C, resulting in high energy consumption and atmospheric pollution due to waste by-products.

Moreover, this graphitization method is selective toward raw materials. It is only applicable to carbonaceous materials with layered carbon atom arrangements in their basic structural units, such as petroleum coke and pitch coke. Conversely, hard carbons like resin carbons or glass-like carbons, which exhibit porous and disordered turbostratic structures, cannot be graphitized even at temperatures above 2000°C.