Which thermal management factors impact your battery performances?
In this blog post, we will succinctly summarize the main factors that come into play in battery performance: Thermal Management, Thermal Shock, Fast Charging and Battery Capacity & Lifespan and choice of Thermal Interface Materials (TIMs). At the end of this article, we’ll also look at an important consumer requirement: the pleasure of driving.
Battery Performances and Thermal Management
Thermal Management Systems (TMS)
The term ‘Thermal Management’ is used in its widest sense, including thermodynamics, heat and power transfer, insulation, conduction, convection, condensation, radiation, etc.
This is the main challenge: maintaining battery cells within their optimal ambient temperature, between 15°C & 35°C, where they perform best. At any higher temperature, performance declines and batteries age more quickly, losing power potential over time.
When functioning, the battery itself generates heat. Added to that, it’s important to factor in outside climate variations, from intense tropical or summertime heat to freezing temperatures in Arctic or wintertime conditions.
So, the first decision material engineers and battery specialists need to make is what TIMs best meet their specific needs. In this initial phase of decision-making, silicones should definitely be considered since they offer several advantages, especially for dealing with extreme conditions and providing reliable operation of the power system and long-term performance.
Batteries basically lose their charge more quickly due to two main factors: driving at high speeds on highways and stop-and-start urban driving conditions. And, of course, many of today’s battery packs have a limited capacity to store energy for a full day of driving, although this is rapidly progressing. It is therefore essential to be able to recharge battery power at high speed charging stations. We can now totally recharge a battery in 30 minutes or less, while shopping at the supermarket or while taking a break for a quick snack or meal. The fact is that the faster you recharge, the more heat your battery generates. This is why carmakers are working on controlling this excess heat and silicones are an essential component in evacuating the heat (thermal conductivity) or insulate each cell from each other to prevent thermal runaway. Learn more about these thermal management methods by downloading by getting our eBook:
Battery Capacity & Lifespan
One of the major challenges in the generalization of all-electric cars has, for the last few years, been the capacity of batteries to provide enough autonomy for intensive use or for driving long distances. This is being dealt with in several ways, in particular by designing a new generation of power packs with better performance and fast-charging stations. In all of these advances, Temperature Management Systems (TMS) and Thermal Interface Materials (TIMs) are key factors and silicones should be considered for their ability to control temperatures and ensure optimal performance. Battery lifespan is also improving, an important factor in optimizing the cost of electric vehicles in the long run commonly called “Total Cost of Ownership” (TCO). To summarize, batteries are more durable if they stay within a specific temperature range and, of course, this is the main contribution that silicone materials can potentially make in that regard.
The Pleasure of Driving
The driving experience is not just about technical performance; it’s also about the sheer pleasure of driving. Anyone who’s ever been in an all-electric car has felt the pleasure of its smooth ride, the silence of its motors and the incredible feel of acceleration without gear changes. Carmakers and battery designers are today working hard on ensuring the right balance between providing an exhilarating and safe drive coupled to dependable, energy-saving and eco-friendly systems. Thermal Management of battery packs, in this regard, is also a key factor.
All the factors mentioned in this overview can be integrated upstream into the design of your battery pack and downstream in the manufacturing process. At any given point, you might need to identify a specific TMS solution. We invite you to do our Quick Materials Checklist to pinpoint your main requirements.
Definition of Thermal Interface Materials
Thermal Management Systems are critical in ensuring battery performance, reliability and lifespan, by controlling heat generated by battery operation and external factors, such as outside temperature. This is achieved by using Thermal Interface Materials (TIMs) that can be made of various materials in the form of pads, greases, liquid gap fillers, adhesives, etc. Increasingly, silicone is being used as the material of choice, either on its own in specially designed silicone elastomeric formulations or in composites that include specific fillers.