Synthetic graphite is a carbon material that is manufactured through the high-temperature treatment of carbon precursors, often petroleum-based materials or coal tar pitch. It is used as the anode material in lithium ion batteries, as crucibles in foundries, and many other applications in between. Synthetic graphite oxidation refers to the process by which synthetic graphite materials react with oxygen in the presence of heat, such as when graphite is used in the steelmaking process. Oxidation leads to the formation of various oxidation products which can degrade properties of graphite that make it such an attractive material in the first place. Over time, oxidation can affect the thermal and mechanical properties of graphite, causing graphite components to require repair or replacement. Replacing graphite components can be costly. Whether a company is in the business of steelmaking, constructing parts for rockets going to space, or any other venture where graphite components are exposed to high-heat environments, that company can benefit from several oxidation mitigation strategies. We at Semco are graphite experts who can help you take steps to protect your graphite components from oxidation.
Synthetic Graphite and Oxidation
When synthetic graphite is exposed to elevated temperatures in the presence of oxygen, oxidation reactions can occur, resulting in the transformation of carbon atoms into carbon dioxide (CO2) or other carbon oxides. The rate and extent of oxidation depends on factors such as temperature, oxygen concentration, and the specific structure and purity of the synthetic graphite.
Synthetic graphite is generally highly stable and resistant to oxidation, especially at lower temperatures. However, at very high temperatures, such as those encountered in extreme industrial or aerospace applications, or in the presence of certain catalysts, oxidation can occur.
In industries that require extremely high-temperature processes, such as steelmaking or advanced material synthesis, the oxidation of synthetic graphite components can be a concern. It can lead to the degradation of equipment and affect the efficiency of processes.
In aerospace applications, such as spacecraft reentry or rocket nozzles, the extreme heat generated during reentry can cause synthetic graphite components to oxidize. This can affect the performance and structural integrity of the components. While this example demonstrates the very high stakes of protecting graphite from oxidation–no one wants to see a spacecraft fail–the same dangers facing rocket nozzles passing through Earth’s atmosphere can affect more mundane graphite components that face similar heat-intensive conditions.
Synthetic graphite is also used as an anode material in lithium-ion batteries. While the primary concern in battery applications is not oxidation but rather intercalation of lithium ions during charging and discharging cycles, high temperatures and exposure to oxygen can still impact the material's stability over time.
Protecting Graphite Components from Oxidation
To mitigate or control synthetic graphite oxidation, various strategies can be employed. These strategies, which Semco is happy to consult with you about, can involve everything from using protective coatings, to selecting high-quality graphite grades with lower susceptibility to oxidation, to controlling the operating conditions to minimize exposure to high temperatures and oxygen-rich environments. If your manufacturing set-up depends on graphite components that frequently require replacement, or if you have experienced an unexpected failure of a graphite component due to degradation of the material, reach out to us. Our graphite experts can work with you to select more appropriate graphite grades or protective coatings. Custom graphite solutions are our business, and we are ready to assist wit