NMC Battery Chemistry

[BahamaTodd]

One of the reviews I watched mentioned that they are using NMC for their batteries. I'm actually surprised/disappointed they don't have an LFP option. But it seems efficiency isn't this thing's strong suit considering the battery kWh capacity so they had to go for the most energy density.

 

[Slate81]

For those curious about NMC...


Key Features:

• High energy density: Provides good range for electric vehicles (e.g., trucks like those discussed on Slate Auto Truck Forums).
• Balanced performance: Nickel boosts energy density, cobalt improves stability, and manganese enhances safety and reduces costs.
• Long cycle life: Can handle many charge-discharge cycles, though lifespan varies by usage.
• Applications: Common in EVs (like Tesla, GM, or Rivian trucks), laptops, and grid storage.

Pros:

• Good power output and efficiency.
• Versatile for various climates and conditions.
• Cost-effective compared to some alternatives (e.g., cobalt-heavy batteries).

Cons:

• Contains cobalt, which raises ethical and supply chain concerns.
• Less stable at high temperatures compared to other chemistries (e.g., LFP batteries).
• Performance depends on the specific NMC ratio (e.g., 811 for high nickel, 532 for balanced).

 

[Liontracks]

For those curious about NMC...
Cons:

• Contains cobalt, which raises ethical and supply chain concerns.
• Less stable at high temperatures compared to other chemistries (e.g., LFP batteries).
• Performance depends on the specific NMC ratio (e.g., 811 for high nickel, 532 for balanced).

Hmmm your list of cons does make me curious about your second bullet point. What is the threshold for heat? Like would someone from Arizona or any of the other US desert states need to be concerned about that?

 

[Slate81]

Hmmm your list of cons does make me curious about your second bullet point. What is the threshold for heat? Like would someone from Arizona or any of the other US desert states need to be concerned about that?

NMC (Nickel Manganese Cobalt) batteries start to show thermal instability at high temperatures, typically above 60°C (140°F), with significant risks of degradation or failure escalating around 80°C (176°F) and beyond. Here's a breakdown:

• Above 60°C (140°F): Prolonged exposure can accelerate capacity fade, reducing the battery's lifespan. Chemical reactions within the NMC cathode (e.g., electrolyte decomposition) speed up, causing gradual performance loss.
• Above 80°C (176°F): Risks increase for thermal runaway, where the battery overheats uncontrollably, potentially leading to fires or explosions. This is more likely if the battery is overcharged, damaged, or poorly managed.
• Extreme cases (100°C+/212°F+): Direct exposure to such temperatures (e.g., in a fire or severe environmental conditions) almost guarantees catastrophic failure.

Context for Stability:

• Battery Management Systems (BMS): Modern NMC batteries in electric trucks (like those on Slate Auto Truck Forums) use advanced cooling systems (liquid or air) to keep temps below 40-50°C (104-122°F) during operation, mitigating risks.
• Comparison to LFP (Lithium Iron Phosphate): LFP batteries tolerate higher temps (up to ~100°C/212°F) before significant instability, making them safer but less energy-dense.
• Environmental Factors: High ambient temperatures (e.g., desert climates or heavy-duty truck use in summer) can push NMC batteries closer to these thresholds without proper cooling.

Via GrokAi

So, I would say you'd be alright in AZ, those are extremes.

 

[cvollers]

I believe Toyota exclusively uses NMC for their batteries and include cooling/ventilation in their applications (eg. new Land Cruiser). That adds a bit of complexity and cost that Slate most likely would like to avoid.

 

[<3 Crank Windows]

Slate Auto decided against using LFP batteries because they wanted to make sure the truck qualified for the $7,500 federal EV rebate.

Here's an article on it:

Why The Slate Truck Doesn’t Use LFP Batteries

It's all about making the truck qualify for the $7,500 federal EV rebate, Slate's CEO told InsideEVs.

https://insideevs.com/news/757802/slate-ev-battery-chemistry-lfp/

Cheap electric vehicles have been elusive for years, in part because EV batteries have historically been so expensive. So this truck could be a very big deal once production starts in late 2026—if Slate can avoid the pitfalls that tanked other EV startups.

Given the whole battery-cost hurdle, you might expect the startup’s pickup to use lithium-iron-phosphate (LFP) cells, a chemistry that’s gaining traction worldwide thanks to its lower cost. You’d be wrong. Slate is going with pricier and more typical nickel-manganese-cobalt (NMC) batteries.

Chris Barman, Slate’s CEO, told InsideEVs it came down to where the supply chains for these two chemistries are located. She explained it would’ve been challenging to comply with the EV tax credit’s battery-sourcing requirements while using LFP.

“We've gone with more of what's in the mainstream right now and that many others in the industry are using. So we're using more of what's been scaled within the U.S.,” she said. “For LFP, most of those materials would come out of China or elsewhere.”

The $7,500 federal rebate for EV buyers is a key driver of Slate’s price proposition, especially given how bare-bones its truck is before options. (It sports crank windows, no radio and a 150-mile range.) But the incentive isn’t available for buyers of just any vehicle. EVs need to be produced in North America. Slate’s got that covered with a factory opening up somewhere in the Midwest.

And the battery pack that powers a qualifying vehicle can’t use components or critical minerals that come from a “foreign entity of concern,” which is government-speak for adversaries like China. The rules, passed during the Biden administration, aim to spur more domestic EV and battery manufacturing, while also making the car industry less reliant on China. That country has a stranglehold on global battery production. By some estimates, it’s responsible for 98% of the world’s supply of active materials for LFP batteries.

On top of that, battery cells need to meet requirements for both their components and raw materials that get stricter each year throughout this decade. By 2029, 100% of a qualifying vehicle’s battery components must be made in North America. By 2027, 80% of an EV battery’s critical minerals must be recycled in North America, come from the U.S. or come from a country the U.S. has a free-trade agreement with.

It’s a lot to deal with. But Slate has the advantage of being able to set up its supply chains with these rules already in place. As the requirements have tightened up, manufacturers with EVs already on the road have had to scramble to remain compliant, with some models losing tax-credit eligibility altogether.

Of course, there’s also no guarantee the EV tax credit will remain on the books much longer. President Trump and his allies in Congress have proposed killing the subsidy.

At the end of the day, Slate went with U.S.-made NMC cells from the South Korean battery manufacturer SK On. The automaker inked an initial deal to purchase 20 gigawatt-hours of battery cells through 2031. That adds up to around 380,000 of its 52.7-kilowatt-hour packs. (Slate will also offer a larger 84.3-kWh pack with extra range.)

Another reason Slate went with NMC was its superior energy density. LFP packs are durable, known for their fast-charging abilities and use cheaper raw materials. But an NMC pack that takes up the same amount of space will generally deliver more range.

Eric Keipper, Slate’s head of engineering, said the automaker could’ve managed the 150-mile range of its base vehicle with LFP cells. But energy density would’ve been a problem for the longer-range, 240-mile version. That makes sense, given that the Slate truck is pretty tiny and there’s only so much space in the floor for battery cells.

“We wouldn't have necessarily been able to get the energy density with LFP. So that was one of the factors,” he told InsideEVs, when asked about the decision between the two chemistries. “But really it’s the availability in the United States.”