US researchers have published a study showing that the lifespan of electric car batteries is often underestimated.
The SLAC-Stanford Battery Center, a collaboration between Stanford University’s Precourt Institute for Energy and SLAC National Accelerator Laboratory, has unveiled promising findings on the ageing of lithium-ion batteries, crucial components for electric vehicles.
By simulating real-world driving conditions, the study shows that battery lifespan can be up to 38% higher than that measured using a constant rate of decharge in standard laboratory testing. This corresponds to a significant increase in battery operating life of up to 314,000 km.
The tests show that these dynamic discharge cycles play a decisive role in slowing the rate of battery degradation. In short, standard testing protocols are based on a uniform driving style, whereas real-world driving is quite different. To reach these conclusions, the researchers used 92 commercial lithium-ion cells, all tested under realistic conditions in a 35°C environment.
This research, carried out over two years, highlights the importance of the multiple micro-cycles characteristic of real-life use. Contrary to popular belief, acceleration peaks do not affect the longevity of battery cells – quite the contrary. It does affect range, but not the overall lifespan.
It goes without saying that the life of your vehicle battery will depend very much on the conditions of use (charging frequency, ambient temperature, average mileage, etc), as well as the type of roads and driving style adopted. Over the course of several cycles, the battery's capacity degrades, but much less rapidly than previously assumed.
Ultimately, this study calls into question traditional battery testing methods, which are often based on simplified protocols. It paves the way for more realistic tests, to more accurately meet the needs of motorists, whether or not they have already taken the plunge and opted for an electric vehicle. This research is published in the journal, Nature Energy.
Today, the average lifespan of an electric car battery is generally estimated at between 8 and 10 years, bearing in mind that a battery can withstand around 1,000 charge cycles before losing significant capacity. – AFP Relaxnews
