As the electric vehicle market demands higher performance, longer range and faster charging, improved thermal management becomes absolutely key. The technologies to the high energy density lithium-ion (Li-ion) batteries that most commonly powered battery electric vehicles (BEVs) are evolving all the time.
With that in mind, we’ve put together some of the most important considerations when it comes to thermal management for electric vehicle batteries.
Minimising the effects of thermal runaway
One of the most significant aspects of thermal management in electric vehicles is the risk of thermal runaway. Thermal runaway is a reaction that occurs when a battery cell breaks down, reaches a critical temperature and causes an unstoppable chain reaction resulting in fire and usually explosion. As electric vehicles have become more prominent in the global marketplace, the risk of thermal runaway has been a growing concern. Thermal runaway cannot be prevented, but the effects can be mitigated. The right solution is needed to slow down the reaction and buy the driver and passengers more time to safely exit the vehicle in the event it does occur. Using high- temperature insulation between the cells of the battery pack and surrounding the pack is key in this process.
Constant temperature changes throughout its lifecycle have an effect on the performance and range of an electric vehicle battery. The correct thermal management is key to extending the battery lifecycle and ensuring maximum effectiveness throughout its lifespan. Batteries can generate as much as 250% more heat after 10 years of use when compared to the start of their lifecycle – as this assuming consistent driving conditions and regular charge-discharge cycles. Further study is yet to be done into variable conditions around the use of an electric vehicle and the effects on the battery over its lifetime – and continued development in thermal management will be key in combating the effects of ageing on a battery.
Temperature and performance
As much as the battery “ageing process” has an effect on thermal management, the temperature can also have a direct impact on the lifecycle and performance of the battery. The service life of an electric vehicle battery begins to decreases faster at operating temperatures of 40°C or higher. Efficiency and output are much lower at temperatures below -10°C. High outside temperatures as well as momentary or temporary peaks caused by high current flow from things like recharging and boosting put the battery at risk of surpassing the critical 40°C.
At Elmelin, we’re working closely with the automotive sector to develop and produce solutions to support better thermal management in electric vehicles and for electric vehicle batteries. If you’d like to find out more about our solutions, get in touch.
Although the concept of electric vehicles is not a new one, our understanding of the technology surrounding them and what makes for better, more sustainable, safer and higher performing vehicles is evolving all the time. Obviously, a key component of an electric vehicle (EV) is its battery – this is quite literally what powers the car – so constant development in this area is key in making EVs suitable for the mass market.
Here’s a quick look at where we currently are with electric vehicle battery technology – and where we ideally need to be.
Currently, the leading battery type in electric vehicles is lithium-ion. Early EVs ran on lead-acid batteries due to their high availability and low cost, but as they require frequent maintenance and have a short lifecycle, they are not sustainable as an option if EVs are going to tackle the mass market. In addition, in order to make a lead-acid battery-powered EV comparable with the range and performance of an ICE vehicle, the battery would have to take up 25-50% of the vehicle.
Lithium-ion batteries were originally developed for use in consumer electronics such as laptops. They combine high energy density with a relatively long life cycle, and are relatively low profile compared to the alternatives. There have been previous challenges with li-ion batteries surrounding their response to high temperatures, and the risk of thermal runaway – but more recently, EV battery manufacturers have been working with variations on li-ion such as phosphates, titanates and spinels, that sacrifice specific power (Wh/kg) and specific energy (W/kg) in favour of providing more sustainable features – fire resistance, ecological efficiency, rapid charging and longer lifespans.
Despite the impetus behind the move to electric vehicles being the environmental gains, there is still some concern around the products and byproducts of their manufacture and the impact of those. In 10-15 years, with increased numbers of EVs on the roads, many EV batteries will be coming to the end of their useful lifecycle and will be ready to be replaced. This means that the old li-ion battery will need to be disposed over. Currently, it’s estimated that just 5% of li-ion batteries are recycled – and in some countries, it’s even less. Much of the substance that’s recovered when recycling a battery is what’s known as black mass – a mixture of lithium, manganese, cobalt and nickel – that needs energy-intensive processing to become usable again. It’s vital that manufacturers and the industry, in general, consider how to improve the recyclability of li-ion batteries.
Extending the useful lifecycle of EV batteries
Though li-ion EV batteries tend to have longer lifecycles when compared with alternatives, the lifecycle is still a challenge. EV batteries are reportedly designed to last for around 1500-2000 discharge cycles. Depending on the usage of the vehicle, this could represent anything from 10 to 20 years. Rapid charging, while a convenient concept during day-to-day use, can affect the overall lifecycle and the range that you get from the vehicle over time.
For that reason, it’s important to consider ways in which we can extend the useful life of EV batteries so that things like rapid charging can still be used without having long term effects.
Compression pads can be used to apply physical pressure on the battery pack whilst maintaining thermal and electrical connections, allowing for tolerance and expansion during charging and discharging, or when exposed to external factors such as high temperatures.
Elmelin EV battery solutions
We’re working closely with manufacturers in the battery and automotive markets to develop solutions that will help to improve the lifecycle, efficiency and performance of EV batteries. If you’d like to find out more, get in touch.
We will also be exhibiting at the Cenex-LCV 2021 event, 22nd-23rd September, at Millbrook Proving Ground – showcasing our latest innovations in insulation for automotive and battery technology. Find out more here.
As more industries and applications turn to battery technology in order to create sustainable energy solutions, ongoing research and development into making them safer is vital.
A significant risk to safety which is present particularly in high energy density batteries is thermal runaway. Thermal runaway can cause an unstoppable reaction that leads to incredibly high temperatures and fire which can be difficult if not impossible to extinguish by conventional methods.
So, the ongoing challenge and question is – can thermal runaway be prevented?
As the electric vehicle (EV) market gains momentum, and we creep ever closer to the 2030 deadline for an end to the sale of fossil fuel vehicles in the UK, innovation in the field of EV batteries is happening at a rapid pace.
Even closer deadlines include 2025 for Norway, meaning manufacturers must work to increase the storage capacity and life cycle of battery packs whilst balancing performance, cost and safety.
In this article, we’re going to examine why compression pads for electric vehicle batteries are useful in ensuring optimal performance, extending the life of the battery pack and increasing the safety of the vehicle occupants. …
As part of the global initiative to combat climate change, the sale of non-electric vehicles will be banned in 9 countries by 2030. In the UK, where the date is currently 2035, there has been talk of bringing this forward to 2030. Some countries have plans for earlier bans – such as Norway, which plans to phase them out by 2025, and Austria, who planned to stop the sale of them this year. These initiatives and benchmarks have proven to be the impetus behind legislation, innovation and movement in the electric vehicle market over the last couple of years.
The probability of an electric vehicle (EV) catching fire is significantly lower than that of an internal combustion engine (ICE) vehicle. According to the Fatality Analysis Reporting System, between 1993 and 2013 in the US, fires occurred in 2.6% of EVs, and in 4.4% of ICE vehicles. However, over the last few years as EVs have become more prominent, there have been well-publicised issues with fire occurring in electric vehicles – with Tesla being the worst hit.
Risk is abundant in any motor vehicle – but it’s essential to understand the unique risks involved with manufacturing and operating EVs, and how they can be mitigated.
Here are some electric vehicle safety concerns around battery damage and fire risk and how they can be addressed.…
Mica is an incredibly versatile and flexible material. Due to its unique physical, electrical and thermal properties, it makes an ideal insulation material. Across the broad requirements of industry, there are billions of machines, components and products that need to be insulated – all requiring a slightly different approach, and slightly different material. Because mica is so versatile, it can be adapted into various applications through cutting, shaping and combining with other substances to create unique insulation solutions.
Here are 3 ways in which mica is commonly adapted for use in various applications. …
Thermal runaway is a significant risk present in batteries. It occurs due to a battery cell failure of some kind, occasionally as simple as the separator between the anode and the electrolyte breaking down. This generates an increase in temperature, creating a chain reaction in which more energy is released, causing the electrolyte to break down into flammable gasses. Once the separator melts, the cathode of the battery breaks down further fuelling the fire with oxygen, triggering an uncontrolled positive feedback loop, often leading to a destructive result. The risk of thermal runaway begins at 60°C and becomes extremely critical at 100°C. Once the process has begun, temperatures rise rapidly within milliseconds – creating temperatures of around 400°C. It is particularly prevalent in lithium-ion batteries. …