China’s Contemporary Amperex Technology Co., Limited, better known by its acronym CATL, wants to calm any worries you may have about battery lifespan.
The largest EV battery manufacturer just released a new video claiming that its Long-Service-Life Battery packs can last up to 16 years or 1.24 million miles (2 million kilometers.) That’s a lot of driving. Assuming an EV with some 300 miles of range, we are talking about more than 4,000 full charge and discharge cycles.
Across the world, many automakers use batteries from CATL, including Tesla, BYD, Hyundai, Toyota, Volkswagen and others.
EV battery degradation
Typically, EV batteries gradually lose some capacity (and power) with time, cycle use, or other factors. Manufacturers often cover the packs with an 8-year warranty, but a battery is expected to last much longer (with a lower capacity and performance), potentially as long as the car itself.
CATL’s marketing video does not explain the details behind the Long-Service-Life Battery’s outstanding results. The company’s website clearly states that the battery warranty for passenger EVs is eight years, or about 500,000 miles (800,000 km). Also, the newly launched EV battery brand for commercial applications—CATL Tianxing—is covered by an eight-year/800,000-kilometer warranty.
We can then assume that the 16-year or 1.24 million mile level is a potential output rather than something guaranteed. At least some CATL batteries might reach such a level in relatively good condition.
The Chinese manufacturer briefly listed several technologies related to chemistry that enable significantly extending the lifespan of lithium-ion batteries.
First is its “low-lithium consumption technology,” which stabilizes the surface and structure of anode materials. In addition, a self-passivating film has been adapted for the cathode electrode— something it calls “FIC Coating technology.”
Third is “a bionic self-repairing electrolyte”, which can reverse some of the degradation within the solid electrolyte interphase (SEI) film. The electrolyte also has various layers, to help minimize degradation.
Moving outside the battery cells to the pack level, CATL also enhanced longevity with some mechanical solutions. According to CATL, the electrodes inside thicken as batteries get used, leading to increased swelling stress. The company developed a Flexible Expanding Force Management system to adaptively manage the cell expansion force and minimize the pressure.
We guess this concerns the company’s primary Lithium Iron Phosphate (LFP) lithium-ion chemistry, which is one of the best in terms of longevity.
For reference, last month we reported about the Tesla Model 3/Model Y with Long-Range batteries—most likely NCA or NCM chemistries—which had an average battery capacity degradation of 15% after 200,000 miles (322,000 km). Tesla covers its Long Range Model 3/Model Y with an 8-year or 120,000-mile warranty (whichever comes first).
