New Delhi: As the world embraces the urgent need for green mobility solutions, global electric vehicle (EV) adoption has skyrocketed – revolutionising the future of transportation. Battery packs lie at the heart of this transformation and serve as the life force of EVs. This calls for a meticulous design and development process of EV batteries for their seamless functionality on the road. A few key aspects including spatial structure, electronic control, mechanical assemblies, and most importantly, thermal management systems are to be proficiently simulated for real-world usage conditions.EV battery modules are designed to operate within specific temperature thresholds during charging and discharging. Although cell manufacturers provide guidelines for safe operating temperatures based on extensive research and development (R&D), diverse climate conditions during usage can pose unique challenges. In countries like India, where weather conditions range from the extreme cold of sub-zero to scorching heat exceeding 50°C, maintaining batteries within the safe operating temperature becomes crucial. Most batteries are best maintained within the optimal operating points of 25°C to 30°C. Therefore, effective thermal management is imperative to ensure batteries perform at their best despite varying external conditions.Batteries generate heat even when they are charging. Compared to fixed battery systems, swappable battery systems offer the advantage of battery removal from the vehicle, allowing them to be cooled in temperature-controlled swap stations. This ensures that the charging process is done under optimal battery temperatures ensuring longer life and safety. Such a mechanism also provides greater flexibility for updating and upgrading thermal management technology.
The Indian electric mobility scenario is still at a nascent stage – making technological advancements crucial. Entrusting battery management solely to end-users, who may lack technical knowledge, increases the risk of overuse and overheating during continuous charging, discharging, or fast charging without appropriate breaks. Inbuilt technology should therefore enable user-friendly operations, allowing customers to safely use their batteries without requiring manual intervention. Furthermore, there is a need for improved cooling systems which significantly reduce cooling time to enable faster 0-100% charging. Such advancements in thermal management will ease EV usage and bolster confidence in battery reliability and performance.
Advantages of internal cooling systems
Internal cooling systems offer several performance advantages. They include extended battery life and range, enhanced safety and optimal performance.
Extended battery life and increased range: By maintaining the battery operating temperatures within set thresholds, internal cooling systems reduce capacity fade, ensuring that the battery module lasts longer without compromising its full charge capacity. This will allow EVs to travel farther on a single charge for a longer lifetime of the battery.
Enhanced safety: Continuous operation of battery packs at higher temperatures can eventually lead to thermal runaway, posing a significant safety risk. With a thermal management system, potential issues can be detected in advance to prevent battery fires. Stringent certification standards, like the AIS-156 Amendment 3, now mandate various tests – including thermal shocks and propagation to ensure battery safety.
Optimal performance: Maintaining batteries at the ideal temperature range through internal cooling systems optimises their performance. The overall efficiency of a battery pack increases when they are within the recommended temperature limits. Better performance directly translates to energy efficiency and enhanced user experience.
The significance of cooling systems in battery packs cannot be overstated, as they play a vital role in preventing fires and curbing other performance-related issues that can have a cascading effect on an EV’s overall functionality. Effective thermal management is key to maximising a battery’s life, range, and safety.
As an industry, we must forge ahead with increasingly energy-dense battery technologies with continuous R&D around thermal management systems. The focus must be on advancing technologies that can effectively operate diverse battery chemistries at varying ambient temperatures. By prioritising this, we can ensure the safe and widespread adoption of EVs, laying the foundation for sustainable and ever-evolving electrified transportation.
(Disclaimer: Gautham Maheswaran is co-founder of RACE Energy. Views are personal.)
