Stellantis, among other manufacturers have been trying to crack the puzzle of making solid-state batteries for electric vehicles due to several benefits offered by the expensive technology. Now they’re doing so with semi-solid-state lithium-ion batteries. Semi-solid-state lithium-ion batteries for example are capable of achieving an energy density (energy-to-weight ratio) of 375 Watt-hours (Wh) per kg.
This means that 1 kg (2.2 pounds) of those semi-solid-state lithium-ion batteries could store 375 Wh of energy. A 1 kg battery of that variety can compete with the 12V lead-acid starter battery used to start traditional cars (at least, the smallest ones), but an equivalent lead-acid battery weighs 21 pounds — Approximately 10 times heavier!
The weight savings could translate to hundreds of pounds if comparing it to a large lead-acid battery for an EV propulsion system. However, that isn’t the fairest comparison as non-solid-state lithium-ion batteries are already dominant in electric vehicles with energy densities exceeding 200 Wh/kg. Nonetheless, lithium-ion batteries are trying to break into the starter battery market.
Stellantis’ approach at the moment is to focus on testing their new semi-solid-state batteries instead of fully solid-state batteries in their demonstration fleet of Dodge Charger Daytona electric vehicles. Semi-solid-state combines (and likely dilutes) the benefits of solid-state and non-solid-state (liquid electrolyte) batteries while making their high performance more financially accessible.
The new Stellantis batteries can be recharged from 15% to 90% state-of-charge (SOC) in only 18 minutes and operate at temperatures ranging from -30C to 45C (22F to 113F).
Significant weight savings brought on by improved battery technology tends to improve performance and driving range in a meaningful way. Improving energy-density and power-density (ratio of the power it can discharge to weight, as opposed to energy density which is energy storage capacity) is how electric vehicles usually gain substantial improvements.
That is also why lead-acid and nickel metal hydride batteries are off the table for electric vehicles. They were too heavy and offered poor performance for the money as a result. Heavy cars require more powerful (and therefore more expensive) propulsion systems to achieve the same level of performance offered by lighter cars, and their handling tends to be inferior.
