New Cobalt-Free Silicon EV Battery Is The Best Thing Ever
New Cobalt-Free Silicon EV Battery Is The Best Thing Ever
A new EV battery deploys 3-D nanostructures that resemble plastic badminton birdies but deliver on cost, performance, and safety.
“This breakthrough development translates into a remarkable improvement in cell-core energy density, reaching 2,000Wh/L in batteries and approximately 1,700Wh/L in full-size EV batteries – more than double the performance of current state-of-the-art technologies,”
“Sienza’s 3D pure silicon anode has demonstrated an average gravimetric capacity of 2,941 mAh/g,” Professor Gharib said. “This means that for every gram of silicon, our batteries can store 2,941 milliampere-hours of electricity, significantly higher than the industry standard for graphite, with a gravimetric capacity of 372 mAh/g.”
Aside from completely avoiding the cobalt issue, Sienza notes that its manufacturing process does not rely on the solvent-based coating systems deployed for producing conventional lithium-ion batteries. Sienza cites one commonly used solvent in particular, N-methyl-pyrrolidone (NMP).
That sounds really impressive. But describing it as "the best thing ever" really has my skepticism at full mast.
ETA: I can't find any mention of a single drawback or tradeoff to this new technology. That makes this a marketing piece rather than journalism. Nothing is ever better in every conceivable way than the current state of the art.
Nothing is ever better in every conceivable way than the current state of the art.
Probabilistically, sure, but it's not impossible that there has been some piece of knowledge or understanding that's been missing, and that massive breakthroughs are possible once the process is figured out.
I think a fair modern example is LED light bulbs. They are better in every conceivable way than incandescent or fluorescent lightbulbs: they last longer, use less energy, shine brighter, use less toxic materials, and are easy to mass produce. But there were several decades where much of the industry believed that LEDs would never be very useful as a light source because we could only produce red and green, and it was generally believed that a blue LED would be impossible to produce.
Then one guy decided it would be his life mission to invent the blue LED, and the sonuvabitch did it. Now LEDs are the only sensible thing to use to produce light.
It's always possible for this kind of breakthrough to happen, especially in material science where the complexity of how molecules interplay is nearly incomprehensible.
Possibly difficult to mass produce. That’s usually what kills all the new great battery tech.
Sienza calculates that its battery cells cost 48% less than conventional cells to manufacture.
I hope this encourages some manufacturers to endorse it and bring it to market. That could make them save and profit a lot compared to other battery tech manufacturers.
Even if this gets relegated to niche applications, all improvements are good improvements.
At the very least, it demonstrates that certain targets are possible, and that's sometimes necessary to secure funding to find those cheaper/scalable options.
I'm doing a PhD in batteries. Not this issue specifically, but I hear a lot about different battery fields so I think I can speak on it.
The drawback is that the anode expands and contracts a lot during a cycle. This puts a lot of strain on the binder holding the film together, and on the contact between the film and the aluminum foil. This makes the battery degrade and fail after fewer cycles.
Below is an article in nature from 2020 where a group is trying to solve this issue by coating the Si platelet particles with carbon (adding complexity and mass). You can read about this issue on greater detail in the abstract and introduction. There are many articles tackling the same issue (many cited in this article), I just picked this one because it had info in the intro/abstract. Stable high-capacity and high-rate silicon-based lithium battery anodes upon two-dimensional covalent encapsulation
In addition, the expansion/contraction cycles causes the electrolyte to dry up. During the first few cycles of any battery, the electrolyte reacts with the electrodes to form passivating layers on the electrodes. When the particle contracts/expands excessively, the particle breaks apart and the passivating layer is ripped up. The passivating layer is then reformed, now on a larger area, which consumes more electrolyte. Eventually the cell fails from the lack of electrolyte.
Below is an article in nature from 2024 where a group tries to solve this issue by designing an electrolyte that creates a passivating layer that keeps its shape when the particle contracts, creating a shell. You can read more about the issue In the abstract, intro, and figures. High voltage electrolytes for lithium-ion batteries with micro-sized silicon anodes
These are solvable issues, but a lot of the solutions are either too complicated to scale up, or add too much mass/volume to make it worth it, or slow down the discharge rate. And any change anywhere, needs to be taken into account on the rest of the parts of the battery.
I don't know what Sienza Energy did. It's an MIT spin-off, so they probably know their stuff. All issues don't need to be solved for a battery to be functional, it just needs to be good enough. Any new battery factory "just" needs to find and scale-up the state-of-the-art components in the right combination. There will be a ton of drawbacks, but it will be better than the last battery factory.
Any expert opinion on this idea? https://spectrum.ieee.org/flow-battery-2666672335
I've decided to just ignore battery hype and tune back in when it's time to swap out my house battery in 5-10 years. Hopefully some of the vaporware will have actually materialized in the market by that time.
Sodium ion and iron batteries making big commercial plays this year
Every three months we get new battery hype...
Given these ratios it sounds like it's more energy dense and less mass dense. That's impressive. Hope it is commercially viable.
In other words, I think "9 times more energy dense per gram" is probably far more laudable than "twice as energy dense per liter", especially in EV applications, where battery packs are significant weight, and weight reduces "efficiency" (obviously they are just as efficient, but it takes more energy to move the added weight. You know what I mean)
Weight isn't as big a concern with EVs because they require more energy to accelerate, but they get more energy back when regeneratively braking. The biggest impact on EV range is aerodynamic, by a long shot. The F-150 lightning, for example, has the same efficiency with the standard and extended range batteries, even though the extended range battery is 500 lbs heavier.
2024: “New Cobalt-Free battery will solve all of our problems!”
2029: “Climate activists concerned that opening hell portal to create cobalt-free batteries may have accelerated global warming”
Just send in the Doomslayer, we'll be fine
Hey, anything that's not Silver Energy is ok in my book as far as hell portals are concerned.
Why am I reading what looks like a bullshit fluff piece designed to drum up naive investor interest?
Because green something something.
That article is so positive it almost reads like an ad. I'm suspicious, but hey if it can melt my phone last longer, I'll keep a gram of optimism.
It's also suspicious how they talk about the volumetric efficiency and dance around mass efficiency. Taking up less space is nice, and it can't be completely ignored, but it's not the primary thing EVs need. It's not even that big of a deal for stationary grid storage.
Interesting typo. Almost like a Freudian slip but with melting batteries instead.
Permanently Deleted