Vacuum Outgassing Thermal Schedules for Atomized Tool Steel Powders
Vacuum outgassing atomized tool steel powders between 180 and 650 degrees Celsius under high vacuum removes surface contaminants and prevents particle boundary failure.
Oxide Film Decomposition
Meaning
Thermal breakdown of the protective passivation layers on metallic surfaces or electrode powders alters the electrochemical stability and safety profile of a battery. The process of oxide film decomposition occurs at elevated temperatures, exposing highly reactive metals to the electrolyte or surrounding atmosphere. Controlling this decomposition is necessary for preventing thermal runaway in lithium-ion and other advanced batteries.
Breakdown Mechanism
High temperatures trigger chemical reactions that destabilize the metal-oxygen bonds, releasing oxygen and generating heat. This oxide film decomposition accelerates the degradation of the active materials and can lead to self-heating. Once this threshold is crossed, the battery enters a rapid, self-sustaining heat generation loop.
Sourcing Requirement
Procurement teams specify cathode materials with highly stable surface coatings to resist this thermal degradation. Resisting oxide film decomposition at higher voltages and temperatures enables the production of safer cells with longer cycle lives. Sourcing from suppliers with advanced surface modification technology reduces the risk of field failures.
Quality Control
Analytical techniques such as thermogravimetric analysis are used to measure the start temperature and energy release of this breakdown. If the oxide film decomposition occurs at too low a temperature, the batch of raw material is rejected. This rigorous screening ensures that only thermally stable materials enter the assembly line, protecting the manufacturer from the massive liability of producing cells that could fail under normal operating temperatures.