Gigafactories need low-energy dehumidification

Jesper, a dehumidification expert at Cotes, shares why humidity in lithium-ion battery manufacturing is such an issue and how battery manufacturers can dramatically reduce the energy consumption of battery dry rooms and therefore, the overall battery production process.  Connect with Jesper on LinkedIn or write him an email at jlj@cotes.com. 

Marta: Let's start at the beginning. What do dehumidifiers do? 
Jesper: A dehumidifier essentially removes moisture from the air and helps you manage the humidity level of an enclosed space. There are different types of dehumidifiers – at Cotes we make adsorption dehumidifiers for industrial applications that can handle a large range of airflows and humidity levels energy-efficiently (learn more about adsorption dehumidifiers here). 

Marta: Why do we need dehumidifiers in Li-ion battery manufacturing? 
Jesper: With battery production, there is a lot of delicate chemistry involved that can react adversely to the presence of humidity. These hypersensitive processes require an environment with a very low dewpoint to ensure the quality and safety of the batteries, which is why you need a dehumidifier to keep the air very dry. We are also looking into the new technologies that are being developed for the future of battery production – and all types of battery production require partial or entire production environments to be extremely dry. 

Marta: What are the challenges faced by the battery industry when selecting dehumidifiers, and what process parameters at they looking for? 
Jesper: Battery manufacturers are hard-pressed to keep reducing energy costs and cutting the embedded carbon footprint of battery cell packs without sacrificing safety or product quality. The battery market is also getting more and more competitive, so reducing energy usage and costs is becoming business-critical in many instances. Battery dry rooms use a lot of energy. Up to 43% of total energy consumption in the battery manufacturing process is for keeping the dry rooms super dry — at dewpoints ranging from -40°C to -65°C equivalent to a relative humidity far below 1%. So, battery manufacturers have a choice: – save on CAPEX by buying a cheap high-temperature dehumidification system or reduce OPEX and embedded carbon by investing in a low-temperature dehumidification system. As we show in several case studies, investing in a low-temperature system, i.e., Cotes Ultradry, can result in massive cost and carbon savings with a very short pay-back time (ROI). And in the current energy market in Europe with gas being phased out and very high electricity prices, Cotes Ultradry Dehumidification makes a very attractive business proposition. 

Marta: What makes Cotes Ultradry dehumidifiers such an attractive business proposition for battery manufacturers? 
Jesper: The patented Cotes Exergic Technology we use in Cotes Ultradry dehumidifiers enables low-temperature dehumidification which means you don’t need to burn gas to reach high temperatures or use a lot of electricity. In fact, all you need is a hot water supply of 80-90°C. This allows the system to utilise more sustainable energy sources (such as solar, thermal, waste heat, district heating, or an energy-efficient heat pump if you are willing to replace the chiller with a heat pump). Furthermore, running the system on heated water provides a high level of flexibility in terms of energy sourcing, making the drying system far more future-proof. 

Marta: 80-90°C seems like a very low temperature to extract humidity. What is the catch? How is Cotes’ technology so energy-efficient? 
Jesper: I know it sounds a bit fantastical, but it is true – and backed up by data. We are seeing savings of up to 92% in net energy usage in battery dry rooms, depending on the project specifications. There are jaw-dropping results from recent installations at some of the biggest gigafactories in Europe, and leading research facilities are confirming the data. In a specific case, Cotes Ultradry dehumidifiers saved 85% of the battery dry room energy usage compared to our closest competitor. That is equal to 49% net energy savings for the whole battery manufacturing plant and represents a *7.8% reduction of the total embedded CO₂ footprint of batteries produced at this facility. Consider that for a second. We calculate the ROI for the dehumidifiers is just under 6 months and when you look at the lifetime of the factory, that is a massive cost saving and carbon footprint reduction. 

*Currently, 19% of the energy demand for a lithium battery pack stem from battery cell production (page 18 at ivl.se). 

Marta: What does the future have in store for Cotes Ultradry? 
Jesper: When we look at the trends and the technology that is being developed, we foresee a big demand for low-energy dehumidification.  
 
Marta: Thank you for your time, Jesper. 
 
For more case studies of Cotes Ultradry Solutions and Lithium-ion battery manufacturing:  

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