Later this year, the world’s largest all-electric container ship is expected to take its maiden voyage, setting sail from a port in Norway and traveling down the Scandanavian coast. Known as the Yara Birkeland, the ship was commissioned by Yara, a Norwegian fertilizer company, to move its product around the country. The company expects the ship to reduce carbon emissions by eliminating about 40,000 trips each year that would otherwise be made by diesel-powered trucks.

There are about 50,000 cargo ships operating around the world, and each year their engines spew about 900 million metric tons of CO2 and other pollutants into the atmosphere. Indeed, the 15 largest container ships alone emit more nitrogen oxide and sulphur oxide pollutants than all the world’s cars combined. Electrifying cars and other modes of transport promises to significantly reduce greenhouse gas emissions, and the same is true of the shipping sector.

Yara Birkeland illustration showing it being docked
An illustration of the Yara Birkeland, which will transport cargo in Norway using battery power.
Courtesy of Yara International ASA

But conventional lithium-ion batteries can only pack enough power to move small ships like the Yara Birkeland over short distances. If we want to electrify the world’s largest cargo ships, we’re going to need some better batteries.

Building battery-powered ships comes with two big problems. The first is that conventional lithium-ion batteries pose safety risks, because they use liquid electrolytes to carry lithium ions between the electrodes. If the components in a battery degrade, this can cause the cell to rapidly heat up and fail, a process known as thermal runaway. The battery’s heat can lead to a cascade of failures in nearby batteries. If these batteries release their chemicals as they fail, all it takes is one battery to catch on fire and cause a large explosion. That would be bad anywhere, but it’s particularly bad at sea where there are millions of dollars of cargo on the line and limited escape routes for crew.

Last year, a small fire in the battery room of a hybrid-electric ferry in Norway resulted in an explosion. The ferry operator was able to evacuate passengers and crew to land before the explosion, but a similar event on a cargo ship in the middle of the ocean could be catastrophic.

SPBES, a Canadian energy-technology company, is working to reduce the risk of electric vessels by designing marine energy systems that are resistant to thermal runaway. The company’s energy system, which is currently installed on roughly 20 ferries and tugboats around the world, uses lithium nickel manganese cobalt, or NMC, batteries. This is the same conventional lithium-ion chemistry you’ll find in most consumer electronics or electric vehicles, which have had their fair share of thermal runaway problems.