Electric Vehicles (EVs) are the future of the automotive industry and the demand for lithium-ion(Li-ion) batteries for use in EVs is expected to reach 9300 GWh or 9TWh by2030.The manufacturing of Li-ion batteriesrequires specially designed“dry rooms”as the raw materials used in Li-ion batteries are highly reactive to moisture which can reduce the quality and performance of the product.Dehumidifiers are needed to remove the moisture content from the environment in which the batteries are manufactured.
Extremely low humidity levels are crucial forLi-ion battery manufacturers as lithiumeasilyreacts with any water vapour to form dangerous combinations of lithium hydroxide and hydrogen which reduce the quality of the batteries. For this reason,significant levels of energy are involved in Li-ion battery production forrunning the dehumidifiersthat keep the humidity levels well below 1% (-40°C dew point) in key dry room areas.
Cotes ExergicTechnology offers the world’s lowest carbon footprint for a battery dry room by making it possible to use a combination of low-cost and sustainable energy sources such as wind, hydro, solar, waste heat and Biogas. Cotes does not consider gas(used in many conventional dry rooms) as a sustainable sourceof energy.
An analysisdone by Cotes for a large battery manufacturer in WesternEurope using Cotes ExergicTechnology showed carbon emissions reductions of up to 95% and reducedcosts by 66%.This is very promising for the future of upcoming gigafactories to achieve economies of scale and to bring down the $/Kwh.
How Cotes Exergic Technology works:
First, fresh air is dried in two stages, then it is mixed with a large proportion of recirculated air from the dry room before the combined air is dried with the finalrotor. When the air is dried in stages, little by little, high temperatures are not necessary to remove moisture from the dehumidifier’s rotors.
While dehumidification solutions from other companies require temperatures of 130°C or more, Cotes Exergic Technology works with approximately 90°C to extract moisture from the silica rotors. The lower temperature makes it possible to choose a combination of sustainable heat sources. At the core of Cotes Exergic Technology, is the use of hot water to heat the air to 90°C. How manufacturersheat the water is up to them, making it possible for them choose from whatever range of sustainable energy sources are at theirdisposal. This enables huge savings in CO2 emissions for running dry rooms and in some European countries we are seeing carbon reductions of up to 95%.
“If you need 130°C on the heating side, you must bring in a lot of electricity. At 90°C, you can use both district heating and heat pump,” explains Thomas Rønnow, Business Development Manager and Owner of Cotes.
The drying process also requires cooling of the air down to approximately 10°Cbeforeit is circulated through each of the silica rotors. This makes the adsorption rotors more efficient, if a CO2 heat pump is installed both heating and cooling can be utilized, saving even more energy.
Cotes has delivered and installed more than 150 specialist dry room systems for use in Li-ion battery production around for a variety of setups. Cotes has also benchmarked several concepts for dry room dehumidification.