Home and dry – battery cell production in drying chambers

Article of 29 November 2013 

Battery cell production in drying chambers

Pure electric vehicles are more expensive than cars with internal combustion engines, since the battery is a major cost factor and accounts for approximately 30 to 40% of the overall price. In order to reduce these costs, the automation industry has developed mass-market serial production of car batteries. Especially in the production of lithium-ion batteries, manufacturing the cells places a particularly high demand on production technology, as this is where the risk of damaging the sensitive cell structure is highest.

Preventing even the slightest contamination

Contamination with moisture from the air can reduce battery performance. In addition to regulating humidity conditions, care must be taken during battery production to ensure that the electrode material is not contaminated. In particular, contamination with copper, nickel and tin can cause the battery cell to ignite during the charge or discharge process. As a result, battery cell production must take place in a clean and dry atmosphere that offers optimal conditions for the process - the drying chamber. The atmosphere in a clean room contains even fewer impurities, although this is not generally necessary for battery cell production.

How a drying chamber works

The air in the drying chamber is cooled, thus removing humidity. Moisture content rises with temperature. When the air is cooled, the moisture condenses into water (commonly known as dew) and can be removed from the air. The so-called pressure dew point, which is expressed in minus degrees Celsius, is used to measure this. In general, the air to be used in a drying chamber is cooled to minus 70 degrees Celsius before being heated to room temperature and routed into the drying chamber.

Special requirements

Nevertheless, the very low humidity level presents special requirements for the automation technology: if it is not designed for drying chamber conditions, it may lead to ageing and the premature failure of automation components or even entire machines. Therefore, at Festo, automation technology products are regularly tested in the drying chamber. To date, full technical availability has been confirmed. Thus, the automated serial production of batteries is cut and dried.

Technology in 60 secondes: How are battery cells produced?