Lithium battery
production, takes place in controlled environment rooms now commonly referred to as “Dry
Rooms”. Classified as requiring relative humidity (RH) <1% or dewpoints (tdp) of minus 20.0°Cdp and below. Requirements are often expressed in dewpoints as the equivalent relative humidity is close to zero. Low dew point dehumidification systems are the crucial element required in lithium battery production. Dewpoint requirements within dry rooms currently range from
minus 35.0˚Cdp to as low as minus 60.0°Cdp, this point is measured in the return air stream as represents the average across the room. At critical areas such as electrolyte fill the supply dewpoint required can be as low as minus 70.0°Cdp.
Low dew point dehumidification systems are the crucial factor required to prevent the lithium from absorbing moisture vapor from the air.
Violations
of parameters, particularly at critical stages of production, such as
electrolyte fill, will lead to a decrease in the quality of the Li-ion battery. To
maximise product quality, microclimates are often created at critical production
points, where the moisture level in the air should be close to zero as possible.
The next
generation of batteries currently in design, are showing an increasing demand
for even lower dewpoints of minus 75.0°C and below, as such, energy consumption
for maintaining the dry rooms, will continue to form a significant part of the
cost of producing lithium-ion batteries.
To
minimise this production cost, the dry rooms should be constructed in a manner
to reduce infiltration, to as low as practicable. Crucially the room air drying
systems, should be designed to be as energy efficient as possible, and should be
able to react quickly to changing external conditions.
Dryair's focus is the deployment of energy efficient dual rotor, desiccant dehumidifier technology to provide the continuous supply of low dewpoint air into dry rooms.
These innovative designs are now the new benchmark across the battery
industry.
