The difficulties in charging electric vehicles have long put drivers off buying a new electric car, despite the environmental benefits they bring. However, a new electric vehicle battery, designed by a research team at Pennsylvania State University, can be fully charged in ten minutes.
An exciting development, it is hoped that this new technology will help bring more consumers to the electric car market.
Why is fast charging important?
Electric vehicle technology has developed exponentially in recent times, due to increased investment from the automotive industry and a conscious societal shift away from fossil fuels.
Companies that manufacture electric cars, such as Tesla and Nissan, attempt to replicate the consumer experience of combustion engines to try to encourage the transition to battery vehicles. However, combustion engines use well-established technologies and infrastructure, meaning they can be conveniently refuelled in minutes, and have high mile ranges.
Since the government’s aim is to end the sale of new petrol/diesel vehicles by 2030, how can electric car batteries change to appeal to everyone?
The current ‘range anxiety’ felt by drivers considering the change to electric vehicles could be soothed with reliable charging points, supported by high-speed cables and recharging car batteries. One of the main ways to achieve this is to design an electric car battery capable of recharging in minutes, so as to not leave drivers stranded mid-journey.
If the lack of trust in this aspect of electric vehicles was overcome, the country’s carbon emissions produced from transport could be significantly reduced.
What’s in the new car battery?
Pennsylvania’s research team, led by Dr Chao-Yang Wang, found that operating a lithium iron phosphate battery at 60oC created better lithium-ion diffusion, higher electrolyte conductivity, and lowered ionic resistance in the cathode.
The combination of these effects boosted the rate of charge transport in the battery, lowering the recharge time to ten minutes.
Previously, the high operating temperature was considered a cause for concern due to the observed accelerated degradation of hot batteries. However, the study proved that this electric car battery is only held at 60oC during operation which is a proportionally small amount of time (51 minutes out of a 24-hour day).
Better than a combustion engine?
If the battery operating temperature is set to 60oC, the performance of the car is weather-independent. Seriously cold weather, around -20oC, reduces the range of a conventional electric car battery by 62%. Overcoming this problem is essential in cold climate locations, which were previously considered unsuitable for electric vehicles.
The thermally modulated EV battery is projected to retain 70% rechargeable capacity after two million miles. This is greater than 16 times the distance under warranty for the Tesla Model 3, which retains 70% capacity at just 120,000 miles.
This suggests that an electric vehicle fitted with a lithium iron phosphate battery could fully replicate a combustion engine, and even surpass its abilities in certain circumstances
Overcoming a key flaw of lithium batteries
The 2019 Nobel prize in Chemistry was jointly awarded to John B Goodenough, M Stanley Whittingham and Akira Yoshino for their work on lithium-ion batteries. These batteries have since been heavily commercialised because of their superiority in compactness and rechargeability.
Recently, lithium-based batteries have made a controversial name for themselves – due to the Samsung phone recalls. The Galaxy Note 7’s from 2016 had a habit of blowing up and catching on fire. More recently, users have complained of their phone batteries swelling in size, breaking out and cracking the phone.
Researchers studying this have found that the formation of dendrites (affectionately called whiskers) could be to blame. The dendrites start from the build-up of lithium ions on the anode, similar to a stalagmite on the floor of a cave. It rapidly grows into a sharp projection than can break the separator in the battery.
This quickly short-circuits the system, but letting the reaction continue can lead to a fire. Dr Chao-Yang Wang’s team avoided this problem by operating the electric car battery at 60°C, which boosts the diffusivity mechanism and prevents the build-up of lithium on the anode.
What does the future hold for high-speed charging?
This research was published in 2021, and while it may take multiple years of in-vehicle testing to be mass marketed, there is little doubt it will one day be successfully used in electric vehicles. In addition, the current super-fast charging network in the UK is compatible with the use of this new battery. Car advertisement designers are probably already planning what slowed down the acoustic version of a song to put with a lithium iron phosphate battery.
How can the principle of a fast-charging battery be applied to smaller, more mobile technology? Going wireless for days on end with only short charging breaks could be game-changing for a number of portable products. Phone dead while travelling? Laptop on low power in the library? Charge back to 100% with inductive charging in under ten minutes. It could remove the modern inconvenience of being chained to a wall or plug socket.
However, as with many scientific discoveries, there is always the potential for more sinister applications. A drone that doesn’t have to return to its military base for days and is no longer range limited could be unimaginably dangerous. High energy weapons with short recharge times, due to a readily available power source, could have disastrous consequences.
It probably won’t end up in the wrong hands though, right? It’s only Elon Musk.