Lithium-ion (Li-ion) batteries are the current standard for battery packs in electric vehicles (EVs) pioneered by Tesla. Sodium-ion (Na-ion) has established a foothold in lower-priced, lesser-range models coming out of China’s BYD, the current rival to Tesla in the EV marketplace. BYD recently overtook Tesla as the number one EV car manufacturer.
Are Li-ion-powered cars’ days numbered? Tesla doesn’t think so and has continued to perfect the technology by increasing energy density and range with better heat management features while lowering the per-unit cost. As a result, Tesla has been lowering prices on existing models coming off the production lines while developing more affordable future EVs to attract current owners of fossil-fuel-powered vehicles.
Will Li-ion’s Successor Be Lithium-Metal or Solid-State?
The next generation of battery some manufacturers believe will be lithium-metal which uses an electroplated lithium-metal anode instead of the graphite one used in Li-ion.
Lithium-metal batteries have the potential to double the range of EVs. Recent work at Stanford University which I described in Part 1 of this two-part look at EV promise and challenges, shows that discharging a battery after use and letting it rest for an hour with no current running through will overcome one of the perceived weaknesses of lithium-metal. That’s because the batteries degrade rapidly if subjected to a high cycle of charging and discharging without a rest.
If the Stanford discovery catches on, will lithium-metal replace Li-ion as the standard? Some expert industry watchers believe that in two years, lithium-metal will be featured in many EVs.
What about solid-state batteries? The world’s largest automobile manufacturer, Toyota, has been late to the starting gate in the EV market, having developed and perfected hybrid vehicles that use a combination of electric and gasoline-powered motors. Rather than becoming just another Li-ion EV player, Toyota hopes to leapfrog the competition by moving to solid-state-battery-powered EVs by 2027 or 2028.
How do these three battery technologies compare? Check out the key differences below:
| Specifications | Lithium-ion | Lithium-metal | Solid-state |
|---|---|---|---|
| Anode | Graphite | Lithium metal | Lithium metal |
| Cathode | Metal oxide | Metal oxide | Metal oxide |
| Electrolyte | Liquid | Liquid | Solid |
| Energy density | High | Very high | High |
| Fast charge time | 30 minutes | 20 minutes | 10 minutes |
| Range | 500-600 Kms | 800-1,000 Kms | 1,000-1,200 Kms |
Who Else is a Zero-Emission-Vehicle Player?
Toyota has been hedging its EV bets by developing other technologies. It recently announced an ammonia-powered EV. Its Mirai hydrogen-fuel-cell, zero-emission car has seen only limited adoption outside of Japan, offering two models with driving ranges from 570 to 630 kilometres. Beyond its California base, Toyota has shown little interest in marketing the Mirai to the rest of North America. Honda has also dabbled with fuel-cells as an alternative power source in one model it has introduced into the California market. And this year, Toyota has plans to offer an EV in California that uses a lithium-iron-phosphate battery with a 400-kilometre range.
Volkswagen in partnership with Blue Solutions, a French-owned EV and battery manufacturer, has been working on 20-minute rechargeable Li-ion models. The company is partnering with QuantumScape, a U.S. startup to co-develop solid-state battery packs for EVs with driving ranges of 500-600 kilometres and a projected battery life of approximately 500,000 kilometres.
Then there are China’s CATL in partnership with the aforementioned BYD, Korea’s LG, America’s Solid Power, and Japan’s Honda also in the mix to develop solid-state EV models.
When will we see these vehicles on the road? That’s the weak link in solid-state development. Companies have been promising working battery prototypes with all defects and production challenges eliminated for some time and have failed to meet their milestones. Toyota had predicted solid-state models would be on the road by this year. That was back in 2018. Volkswagen has promised to have models for sale by 2025. The reality is different. Toyota now hopes to meet a 2027 or 2028 target date. Volkswagen and the other players in the solid-state-first-to-market race are being more secretive.
