2018 Toyota Prius
Toyota continues to stay the course with nickel-metal hydride battery cells for many of its hybrid vehicles, even though most other hybrid vehicles from other brands have moved on to using lithium-ion cells exclusively.
According to Prius chief engineer Shoichi Kaneko, in an interview this past week at the LA Auto Show, most of Toyota’s current hybrid lineup are capable of easily trading off between the two battery types for one chief reason: flexibility. In being compatible with either one, the company can more smoothly react at a factory or vehicle level to supply shortages or price pinches—for raw materials like lithium or nickel, for instance.
Toyota has sold more than 12 million hybrids worldwide and confirmed that they are a profitable part of the automaker’s business—certainly not a claim that can be made by all companies offering a hybrid. As of September, Toyota sold 34 different hybrid models.
Starting with the 2015 model year, the Prius has used lithium-ion batteries for some Prius models, while others use nickel metal hydride batteries. With the refreshed 2019 Prius lineup that will remain the case, Kaneko confirmed.
2018 Toyota Prius
Current NiMH batteries can handle sudden power demands just as quickly as lithium-ion batteries—which is partly why certain areas of consumer electronics have stuck with NiMH. But the strength of lithium-ion packs is their ability to perform long charge cycles. That’s why all plug-in hybrids, like the Prius Prime, have li-ion cells.
On the other hand, Toyota’s all-wheel-drive hybrids, like the 2019 Toyota Prius AWD-e introduced last week at LA, will for the foreseeable future use NiMH—because it can withstand extreme cold far better, and perform better in the cold temps where you’d expect an AWD vehicle to be used.
Kaneko confirmed that today, a NiMH pack will weigh about 25 percent more (165 pounds, versus 132 pounds) and occupy about 20 percent more volume than a lithium-ion pack with a comparable output and usable capacity. It’s a small enough difference for Toyota to easily sub in either technology—whatever politics, trade tariffs, or simple supply and demand may dictate.