Here’s why Slate changed the battery in its cheap EV truck

Slate, the maker of a stripped-down EV truck, has found another way to simplify its product: the battery.

When the startup revealed its starting price Wednesday — $24,950 before destination, taxes, and other fees — it also said it had changed its battery strategy, removing the 240-mile range but bumping the standard range from 150 to 205 miles.

How Slate pulled it off shows how much the US battery market has changed in the past four years.

Initially, the startup planned to use nickel-manganese-cobalt (NMC) cells. The chemistry is widely used in the automotive industry and is popular for its energy density, which translates into long range. But NMC is also expensive, mainly because of the high prices of nickel and cobalt.

Recently, car manufacturers have started using another chemistry, lithium-iron-phosphate (LFP). Battery packs using LFP are less powerful but about 40% cheaper, thanks in part to less expensive ingredients like iron, one of the main cathode materials, replacing nickel and cobalt.

There were good reasons why Slate, and other automakers, started with NMC. The LFP supply chain today is focused on China. It wasn’t always like that – US battery startup A123 Systems was founded to commercialize the technology. But after a few missteps, it fell into bankruptcy and was bought in 2013 by a Chinese auto parts company. Since then, Chinese battery companies have adopted the chemistry and dominated the production of LFP cells.

LFP’s foreign origin meant that, before last summer, EVs it used would not qualify for a $7,500 tax credit under the Inflation Reduction Act. Only batteries made from materials sourced domestically or from companies with which the US has a free trade agreement will be eligible. But when the One Big Beautiful Act rolled out tax credits, those concerns disappeared, too. Chinese manufacturers were also considered. Slate said it is working with Hefei-based battery company Gotion to source the cells, which will be manufactured at a factory in Illinois, according to InsideEVs.

Another reason why car manufacturers are switching to LFP batteries is their limited capacity. Automakers selling in the US market have prioritized range, although cars that can go more than 300 miles on a charge tend to be pricier – the exact opposite of what the Slate does.

In reality, most people don’t need that much range, and as charging networks grow in size, reach, and speed, range concerns are becoming less and less common. While LFP cells will never match NMC in energy density, modern chemical diversity has helped bridge the gap. Ford, GM, Rivian, and Tesla all offer models that use LFP cells.

The industry’s adoption of LFP cells also coincided with the transition to cell-to-pack technology, which Slate uses to build battery packs.

Previously, when car makers put together a battery pack, they first loaded the cells into the modules, which were then loaded into the pack. That setup allowed them to use pocket cells, which are cheap and easy. But over time, they realized that the modular approach canceled out the cost and weight savings that bag cells offered. Although some EVs still use modules, the industry is moving towards cell-to-pack design, where solid batteries, either prismatic or cylindrical, are loaded directly into the pack itself.

Cell-to-pack streamlines production steps and maximizes energy density per volume, a useful feature for a small EV like the Slate truck. Also, LFP cells can be charged up to 100% with fewer worries about degradation than NMC, meaning drivers can use a full pack every day.

Although there was a time when the Slate leadership had to green light the transition from the NMC to the LFP, the momentum for that decision had been building for years. The LFP won’t take over the entire market — automakers like GM are betting on a completely different chemistry — but its combination of low cost and decent range makes the LFP an obvious choice for what will be the cheapest EV in the US.