Can a lithium‑battery factory use oil‑lubricated air compressors?

Requirements for Compressed Air Quality in Lithium-Ion Battery Production

The manufacturing process of lithium batteries places extremely stringent demands on the production environment. In critical operations such as coating, winding, and electrolyte injection, compressed air comes into direct contact with electrode sheets or the interior of battery cells. If the compressed air contains oil, moisture, or solid particles, it can compromise the battery’s chemical stability, leading to internal short circuits, capacity degradation, and even thermal runaway—serious safety hazards. Consequently, lithium‑battery factories impose exceptionally strict purity requirements on their compressed air, typically demanding zero oil content, an ultra‑low dew point, and dust‑free conditions.

Application Risks of Oil-Lubricated Air Compressors in Lithium-Battery Factories

During operation, oil‑lubricated air compressors inevitably introduce lubricating oil into the compressed air. Even after purification by downstream treatment equipment, it is difficult to achieve completely oil‑free air. Should even trace amounts of oil enter a lithium‑battery production line, they can pose the following serious risks:

• Polarizing electrode and electrolyte: Oils can alter the physicochemical properties of the electrode surface, impair electrolyte wetting, increase internal resistance, and shorten cycle life.
• Cause safety hazards: Oil contamination inside the battery can act as an impurity, puncturing the separator and triggering a microshort circuit. During charging and discharging, this极易 leads to thermal runaway, resulting in fire or explosion.
• Increase production costs: An increase in the defect rate caused by oil and gas contamination can significantly raise scrap disposal costs and material waste.

Differentiated Management of Core and Non-Core Processes

When assessing whether oil-lubricated air compressors are suitable, it is necessary to differentiate between the various air‑consumption processes within the plant:

• Core production process: Such processes as coating, winding, electrolyte injection, and formation—operations that involve direct contact with the battery cell—The use of oil-lubricated air compressors is strictly prohibited., a compressed air source that meets Class 0 oil-free standards must be used.
• Non-core support processes: In processes such as pneumatic tool operation, external equipment cleaning, and finished-product packaging—where there is no direct contact with the battery cells—oil-lubricated air compressors can, in theory, be used.

However, in practical plant planning, to prevent pipeline misconnections, cross-contamination, and reduce management complexity, the vast majority of lithium‑battery manufacturers opt for a plant‑wide, unified oil‑free compressed air system.

Recommendations for Selecting Air Compressors for Lithium-Ion Battery Factories

To ensure product quality and production safety, lithium‑battery factories should adhere to the following principles when selecting air compressors:

• Prioritize oil-free models.: In core gas‑using areas, oil‑free screw or oil‑free centrifugal air compressors should be selected to eliminate oil contamination at the source.
• Improve the post-processing systemIn addition to an oil-free compressor, it is also necessary to equip the system with high-efficiency refrigerated dryers, desiccant dryers, and precision filters to ensure that the compressed air meets the required dew point and cleanliness standards.
• Independent piping designIf there are non-core areas within the plant that necessarily require oil-lubricated air compressors, a completely independent compressed-air distribution network must be established, and any physical connection to the core production‑grade air network is strictly prohibited.