How This Battery Is Revolutionizing Energy Storage

There is no perfect battery. Every one of them has pros and cons. One might be perfect for electric vehicles, but horrible for another use case because of cost, longevity, or power output. But what if you combined two separate technologies into one package? Better yet, what if you could pair two very different batteries together, so they could cover each other’s weaknesses? Well, one company is trying to do just that, and has developed a battery that can achieve incredible ranges for something like an EV, all at a lower price than you might think.

So, are two batteries really better than one?

Electrical Vehicles (or EVs) face numerous challenges. Broadly speaking, they need to be lightweight, charge quickly, hold a charge for a long time, and also offer high performance. And they need to do all that while being affordable at the same time. Otherwise, cost accessibility is a big stumbling block on the road to EV proliferation. Plus, while rare in practice, exploding batteries and flaming EVs get a lot of media attention. That means EV batteries have to be extra safe to ensure that people aren’t afraid of investing in a new electric car.¹ It’s mainly a perception issue, but it’s a genuine concern. That’s A LOT to ask from one battery. So what if instead, we asked that of two batteries?

Enter the Gemini Battery pack by Our Next Energy, or ONE. This battery divides the work between a lithium iron phosphate (LFP) cell and a newer, “anode-free” lithium ion manganese oxide battery (LiMnO) cell.² The LFP half of the battery is “min-maxed’” for fast charging and short bursts of city driving, while the LiMnO half is slow, steady and energy dense, which is perfect for long road trips. This dual-chemistry combines the best of both worlds. Together they form a Batman and Robin of batteries, a dynamic duo that seems to meet all of our EV needs. But if the answer was always “just use two batteries,” why hasn’t someone else done this before? How’s an “anode-free” battery even possible? And what’s the catch?

Let’s start with the LFP side of the equation. We’ve covered these devices many times before, so I’ll keep it brief. An LFP essentially comes with all the benefits that have made the lithium ion the industry standard without cobalt, which is both expensive and difficult to obtain. As a result, LFPs tend to be safer, less toxic, and longer lived than most of their cousins. However, they also tend to have a lower operating voltage, and they have lower energy density, especially when compared to other lithium variants that do incorporate cobalt.³⁴ That basically means they’re a larger, heavier battery. That’s not necessarily what you want for a car, but it’s great for something like home energy storage. I actually am getting LFP batteries for my new home.

Here’s where the “anode-free” LiMnO cell comes in. LiMnOs are a type of secondary battery or energy accumulator. Like LFP batteries, their chemistry uses more common elements and are generally cheaper and less toxic. They’re also thermally stable, which is important for safety.⁵ However, their chemistry means you don’t want to charge or discharge them very often, as they can quickly build up dendrites. Dendrites are pesky metal spikes that slowly build up during charging and discharging and, over time, can threaten to puncture the battery.

Together, these batteries cover each other’s weaknesses. The LFP cell’s thermal stability, long life, and high specific power make them charge quickly and stand up to the hard life of an EV. However, LFP batteries tend to have a low specific energy, meaning they aren’t as energy dense as other types. This means you’ll need a physically larger battery.⁴ But the “anode-free” LiMnO is perfect for long, steady drives as it’s super energy dense, and it can hold onto a charge like a champ. And because you’re only tapping into for the long hauls, it’ll be used less often, giving dendrites fewer chances to form and thereby improving longevity.⁶

Speaking of which, is an “anode-free battery” even possible? Well, that’s a little bit of a misnomer, as all batteries have an anode and a cathode. But the term “anode” is used by manufacturers to describe the active material, usually graphite or silicon, placed on the battery’s current collector. ONE’s new battery doesn’t have one. Instead, as it’s charged and discharged, small amounts of lithium plate onto the copper current collector and function like a standard anode. All of this also saves some material weight and cost.² So, yes, it has an anode, but does not use traditional anode materials.

ONE has doubled down on the savings in other ways, too. The company’s battery formulation uses manganese-rich cathodes and far less cobalt than comparable batteries . Though ONE claims they’re going to ditch cobalt entirely, they haven’t yet. It also uses 20% less lithium, 60% less graphite, and 75% less nickel relative to other batteries.² Cobalt and nickel are rare in our current supply chain, which significantly drives up the price of EV batteries…and therefore EVs. So, because the LFP side of the battery is mainly made up of abundant iron, you end up with a significantly cheaper EV.

It’s also important to consider that over 70% of the world’s cobalt is supplied by mining in the Democratic Republic of Congo, which is tied to some deeply troubling human rights abuses. That’s one reason why the less cobalt is used, the better.⁷ Batteries that incorporate cobalt are also more vulnerable to thermal runaway. So, by minimizing the cobalt in their design, ONE is also minimizing the chance of a fire.⁸ This is because the cobalt-oxygen (Co-O) bond is much weaker than the phosphorus-oxygen (P-O) bond. When a battery overheats, the Co-O bond is easily broken, releasing flammable oxygen quickly, feeding the fire. The P-O bond is stronger and doesn’t release the oxygen as quickly.⁴

Gemini’s patented “skip-cell” safety architecture is also another big contributor to reducing battery overheating and thermal runaway. In a roundabout way, this actually helps the Gemini’s performance, as space that would normally be used by fire mitigation boxes in other batteries can now be packed with more cells, which helps with the weight problem that all EVs face.⁹

But if the dual battery system works so well, why hasn’t anyone tried it before?

Well, we have, kind of. Hybrid cars already work on similar principles. The standard fossil-fuel-burning engine kicks in for higher speeds, climbing hills, and so on, while the battery pack handles the majority of the driving and less demanding tasks.¹⁰ You can kind of think of this as an evolution of that framework. We’re taking what we already know works and upgrading it to a fully battery-powered model. This is another benefit of the Gemini: we’re not dealing with innovative new materials or novel formulations. We’re just combining peanut butter and jelly batteries to make a delicious sandwich.¹¹

Sometimes when things are combined you expect the advantages of both. However, sometimes you get the disadvantages of both as well. How does this battery actually perform? Does it actually work? The answer is looking like a resounding “yes.” In a test drive on December 17th, 2021, ONE put their battery to the test, strapping it into a Tesla Model S. It managed to drive for 752 miles on a single charge. That’s nearly double the Model S’s current range of around 400 miles.¹²¹³ Third-party consumers have also had the chance to take the Gemini for a spin to vet its stats… and those stats are impressive. The battery’s dual-approach allows it to achieve both longer range and improved durability. At a capacity of 1,007 Wh/L for the “anode-free” portion of the Gemini, that’s almost double the typical industry battery’s 550 Wh/L performance. Meanwhile, the LFP battery delivers around 441 Wh/L. For most people, that equates to about 150 miles of driving from a single charge on the LFP alone. After that point, it switches to the anode-free cell to charge the LFP cell, another trick borrow from standard hybrid cars.³¹⁴

Because ONE’s gemini battery was vetted in a third party test, it’s been full speed ahead, with the company rapidly moving toward commercialization. They’ve put out new variants like the Aries LFP and Aries II for trucks, or the Aries grid for — surprise! — grid storage.¹⁵ Next year, ONE will open its One Circle “gigafactory” in Van Buren, Michigan. This 660,000 square foot facility will employ over 2,100 workers, and by 2027 it’ll produce 200,000 EV battery packs per year.¹⁶ Better yet, they’re partnering with major battery recyclers like DTE Energy and 6K Energy in an attempt to make the Gemini as sustainable as possible. Together, with the power of circular manufacturing, they think they can slash carbon emission from the factory by 45%.¹⁷

And the EV industry is already taking notice. BMW has signed an agreement to incorporate Gemini into their iX electric SUV and kicked $65 million dollars into the project. The company is confident that their 2024 iX model will be standardized with a Gemini battery system.¹⁸ Meanwhile, Oman’s Sovereign Wealth Fund (SWF) has bought a minority stake in ONE. This isn’t an economics show, so this is a pretty brisk overview, but countries like Oman are aware that the oil reserves that currently fund them aren’t going to last forever. Their SWFs are very interested in finding investments that will continue to support their states and citizens far into the future. In other words, Oman believes ONE is a safe and lucrative enough bet to stake part of their future on it.¹⁹

Sounds amazing, but there’s gotta be a catch, right? Well, there are a few points that remain unclear for now. First, what’s the actual day-to-day range for this battery if the range extending anode-free battery never kicks in? We’ve mentioned how the anode-free battery charges its LFP buddy on longer drives, but if we never go on longer drives, are we just going to burn out the LFP? Similarly, how long can the new, anode-free side last? If it never turns on because I only ever do city-driving or, conversely, if I take many long road trips, how will that impact its performance and lifespan? And speaking of lifespans, when you combine two batteries with two different lifespans and use-cases, one of them is probably going to make its way to the big battery farm in the sky before the other one. So, is it possible to replace one portion of the battery pack if it dies before its partner does? Or will we have to wastefully chuck the whole thing out? And even if replacing one side is an option, how expensive will it be?²⁰

ONE’s early focus on incorporating circular manufacturing into the batteries does give me hope for some of these questions, but they could still prove to be serious issues to tackle. And while all signs point to Gemini being equivalent or cheaper than standard EVs, the exact cost of the Gemini hasn’t been released yet. For me that’s a bit of a red flag. We can’t say for sure if they’ve really met that “cheaper EV” goal yet.¹²

But with all that said, it’s nice to get a ‘novel battery’ that looks like it might do exactly what it says on the tin. Practically every time we talk about a new battery, we discuss how it probably won’t live up to the hype, but it’s still useful and will find a niche. We don’t have to do that this time! The ONE team are battery engineering veterans; they haven’t made a silver bullet that is allegedly going to slay every energy storage bogeyman. They knew exactly what problems they were trying to solve: increase the range of EVs, make EV batteries safer, and solve the pricey and morally thorny supply chain issues related to cobalt. So instead of a silver bullet, they’ve forged a +3 battery of EV slaying.