Lithium-ion batteries are at the core of driving the performance of EVs and make up the lion’s share of an electric vehicle’s cost. In this article, Deepak Pahwa – Chairman of Pahwa Group & Managing Director of Bry-Air, explains the need for deploying dehumidification solutions for cell manufacturing and battery assembly operations.
The Li-ion batteries come with a wide gamut of advantages entailing high energy efficiency, high power-to-weight ratio, exemplary high-temperature performance, and low self-discharge capacity. In addition to this, Li-ion batteries enjoy better energy storage density, requiring a smaller size. It is well adept at charging and discharging energy safely, along with the capacity to charge in the shortest period of time. Hence, the performance of the EV depends on the efficiency of the Li-ion batteries. It is imperative to lay a strong foundation for the resilient manufacturing of Li-ion batteries. Considering that a faulty battery can give rise to performance and safety issues in the EV, it can lead to the calling off of the vehicle from the market. Incidents such as EVs catching fire can be effectively curbed by the production of quality Li-ion batteries. Therefore, installing highly efficient Li-ion batteries can help the EV meet the specific demands of the market and ensure safety at the same time.
The need for dehumidification for Li-ion battery production
Lithium-ion batteries are affected by uncontrolled temperature and humidity. If the lithium battery is exposed to moisture during production, it may lead to impaired quality resulting in reduced product life, charging capacity and safety concerns.
To avoid that, Li-ion battery manufacturing requires very strict environmental conditions accompanied by constant real-time monitoring. The various materials in a battery are highly hygroscopic (tending to absorb moisture from the air) in nature, which necessitates continuous regulation of humidity level within a narrow range throughout the manufacturing and assembling of the battery. Maintaining the humidity at less than 0.5% in a stable environment is ideal for battery manufacturing.
For achieving stringent environmental conditions, installing a dry room helps in the production of quality batteries. The dry rooms need to ideally maintain the RH at less than 0.5 % during lithium cell manufacturing and 10% for the assembling process with the help of an environment control dehumidification system. At the same time, the moisture control equipment in dry rooms aids in achieving extremely low dew points, reaching up to -80°C which is ideal for processing hygroscopic and moisture-sensitive materials.
- Moisture level in Lithium-ion battery processing areas should have less than (-) 35°C (-31°F) dew-point and/or moisture content of 0.14 grams per kg of dry air.
- Room temperature should be maintained at recommended levels, around 25°C (77°F), with a tolerance of +/(-) 2°C (36°F) along with dew points in the range of (-) 35°C (-31°F). (0.14 g/kg).
- The air change rate in the production room should be 20 to 50 air changes per hour with the maintenance of minimum fresh air introduction for positive room pressure and ventilation for workers.
Considering the critical role desiccant dehumidification plays in manufacturing Li-ion batteries, installing efficient low dew point dehumidifiers becomes imperative to producing quality batteries. Lithium, as a material, is highly hygroscopic in nature. This poses a major challenge as the affinity of lithium to attract moisture can lead to faulty Li-ion battery manufacturing. Which, in extreme cases, can give rise to some serious safety issues such as explosion of vehicles and fire incidents. This requires the Li-ion batteries to be manufactured in a strict moisture-controlled environment with less than 0.5% RH which is achievable with the help of low dew point dehumidifiers. By installing high-performance desiccant dehumidifiers, companies can manufacture high-quality Li-ion batteries to boost the performance of EVs.
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