Lithium sulphur targets 2030 while a solid state rival aims for 2027

Stellantis is betting on lithium sulphur twice

Lithium sulphur is a battery chemistry that swaps the nickel, cobalt, manganese and graphite inside a typical electric car battery for sulphur, one of the cheapest elements used in any battery. In 2023 Stellantis Ventures, an investment fund Stellantis runs, invested in Lyten, a company building a lithium sulphur cell called LytCell. Stellantis says the cell could store more than twice the energy of an ordinary lithium ion battery for its weight, at an estimated 60% lower carbon footprint than todays best lithium ion batteries, and 40% lower than a solid state battery, a design that swaps the liquid or gel inside a normal cell for a solid material and is the top rival to lithium sulphur for weight and range.

Lyten's materials platform is a key investment for Stellantis Ventures, in line with our Dare Forward 2030 goal to accelerate deployment of innovative, customer-centric technologies.

Carlos Tavares, then chief executive officer of Stellantis. Source 2.

A second partner, and a third company working alone

In December 2024 Stellantis added a second lithium sulphur partner, Zeta Energy, through an agreement Stellantis states targets 2030 for batteries to power its own vehicles, with up to 50% faster charging and less than half todays lithium ion price per kilowatt hour. Zeta Energy states its pilot cells, a small test batch built before mass production, already reach 350 watt hours per kilogram in 2026, its own measure of stored energy against weight, rising on its roadmap to 450 in 2027 and 600 in 2028. Theion, working independently of Stellantis, states a target of 1,000 watt hours per kilogram and 1,000 charge cycles, how many times a cell can be charged and drained before it wears out, reached through a 3 phase roadmap naming no year for any phase.

Our collaboration with Zeta Energy is another step in helping advance our electrification strategy as we work to deliver clean, safe and affordable vehicles.

Ned Curic, Stellantis chief engineering and technology officer. Source 1.

The claimed advantage over the newer rival

The 40% figure is a number Stellantis states about its own investment, not an independent measurement, and it sits below the 60% figure the company states against ordinary lithium ion batteries. That 20 percentage point gap means the company claims a smaller advantage over the newer rival than over the older one, worth noticing because solid state is the chemistry most often named as the top rival to lithium sulphur for the same weight and range advantage in an electric car.

The rival is not standing still

Samsung SDI states it will begin mass producing an all solid state battery in 2027, aiming for 900 watt hours per liter, a measure of energy stored for the space a battery takes up rather than its weight, 40% higher than the lithium ion cells it currently mass produces. A pilot line at its Suwon research center began operating in March 2022, and sample cells reached customers in 2023. That gap of 3 years is arithmetic this article performed on the 2 stated dates, comparing 2 different kinds of milestone, a cell maker mass production date against a car maker vehicle production date.

The number none of the 4 companies states

None of the 4 companies chasing lithium sulphur states a cycle life figure for a cell already built and tested at scale, only for future targets. Zeta Energy states no cycle life number at all for its real, current 350 watt hour per kilogram pilot cell. Theion states cycle life only as a future target, 500 cycles in phase 2 and 1,000 in phase 3, neither tied to a year and neither described as already reached. A car battery has to survive years of daily charging, and whether a cell from either company can do that before 2030 or after it is the 1 number none of the 5 sources for this article states.