Sulfur costs a fraction of the cobalt it could replace in a battery

What sulfur costs against cobalt

Sulfur is cheap mostly because almost nobody sets out to produce it. Researchers are testing it as the material for a cathode, the part of a battery that stores energy while it charges, in place of cobalt. The United States Geological Survey states that recovered elemental sulfur comes out of petroleum refineries, natural gas processing plants and coking plants, a byproduct rather than a mined target, and in 2025 the average price for a metric ton of it was 180 dollars. Cobalt is the metal a lithium sulfur cell is built to remove entirely, according to Lyten, a company building the cells. The same government survey priced cobalt at 21 dollars a pound in 2025, which converts to about 46,297 dollars a metric ton, on the order of 257 times more than sulfur, a MAOWCE calculation. That comparison sets a raw commodity against an already refined metal, so the true gap between the 2 mined side by side would be smaller.

Why the cheap material is hard to keep stable

Sulfur can theoretically hold 1,672 milliamp hours of charge for every gram it weighs, a measure of how much electric charge a material can store for its weight, according to a 2016 peer reviewed study in the journal Advanced Science. That capacity is hard to keep. The same study built 2 test cells with different amounts of electrolyte, the liquid inside a cell that carries charge between its 2 electrodes, and cycled each cell 100 times. The cell built with a thicker dose of electrolyte lost 61% of its capacity over those 100 cycles. The cell built with a leaner dose lost 30.5%. Both readings come from the same controlled test, so the difference is the electrolyte amount, not the sulfur itself.

What real cells have achieved since

A 2025 benchmarking study in Nature Communications gathered results from many real lithium sulfur cells rather than modelling one, and found their median specific energy, meaning how much energy a cell packs for each kilogram it weighs, reached 298 watt hours per kilogram, already beating commercial lithium ion cells on that measure, the paper says. The best cell the paper found reached 441 watt hours per kilogram, and further material work could push cells beyond 500. The same paper found a catch, in its most energy dense cell the liquid electrolyte still made up 46% of the total weight, and cells degraded twice as fast when discharged quickly compared with a slow discharge.

One company building it now

Lyten, a company running a converted lithium ion production line in San Jose, California, says its lithium sulfur cell configuration leaves out nickel, manganese, cobalt, graphite, iron and phosphorus entirely. The company states its cell cuts up to 50% of the weight of a nickel manganese cobalt cell and up to 75% of the weight of a lithium iron phosphate cell. Converting its existing line to lithium sulfur production cost less than 3% of the capital a new line would need, Lyten says, and the converted line now runs above 90% yield on both pouch and cylindrical cells. The company also says it secured a 650 million dollar letter of intent from the Export Import Bank of the United States to support expanding production in the country.

Lyten's lithium-sulfur battery has the potential to be a key ingredient in enabling mass-market EV adoption globally.

Carlos Tavares, former chief executive officer of Stellantis. Source 5.