I’m sitting in near silence in my room right now, trying to write this (hopefully amazing 😅) article on the role of batteries in our world. But just as I start to focus, tiny noises grab my attention.
The fan in my computer gently starts whirring. The clock ticking at the back of my room comes to mind. And of course, I’m working by the light coming from my desk lamp. The bond between all those background elements is a battery.
When I look around me, I see batteries powering our world everywhere. It’s crazy to think the world could be any other way — where I don’t have access to a clock or laptop or desk lamp to fuel my creative genius 😎. But this world powered by batteries is relatively new — it’s not even 200 years old!
Until the 1840s, electricity was a freak phenomenon used in circus acts and mad lab experiments in aristocratic lecture halls:
That all changed in the 1840s, when people started to use this new invention called the Daniell Cell. Before then, scientists like Volta had created rudimentary batteries, but they made virtually no impact. After the Daniell Cell though, every day people could do amazing things like power doorbells!!!! 🎉🎉🎉
Okay, okay. Doorbells don’t sound all that interesting. BUT they were a complete revolution in battery technology up to that point — finally making it available beyond hidden science labs. That story makes me wonder though… now, 200 years later, what will be OUR revolution in battery technology???
Sure, it’s interesting to talk about the history of batteries and the out-there geniuses involved. But it’s more interesting to talk about the next big battery breakthrough. Our world now revolves around this technology, so the next person to take it to the next level will be insanely important (and insanely rich 😉💰)
Current Batteries are Great!
*But only compared to 200 years ago 😁
If you haven’t already heard, from the Daniell Cells two hundred years ago to now, there’ve been quite a lot of improvements to batteries. Our current best technology is with lithium-ion batteries — which are not only powering doorbells but also vacuum cleaners!!!! 🎉🎉🎉
*And other stuff too, of course. But mainly vacuum cleaners ;-)
Before I talk about how great lithium-ion batteries are, I need to do just the eensiest-teensiest chemistry lesson. I’ll keep it short and simple, so consider the followingᵀᴹ.
Let’s say you have your typical battery doing your typical battery things… EXCEPT that it has an ocean and two humans in it. On one end, you have Bob who’s all positive and full of energy. On the other, there’s Garry who’s just a little too tired to do the whole being-inside-a-battery thing, so he can seem a little negative.
What Bob has to do in this battery is take all his positive energy, swim across the ocean, and get it to Garry. Garry then gets all charged up and energetic, takes all the energy and does things with it, and eventually returns it to Bob. Then the cycle begins again.
The only problem with this analogy is that chemists don’t like people named Bob and Garry (or people being inside batteries… 😅). So they call Bob the ‘cathode’ and Garry the ‘anode.’ When the battery’s charging, the cathode has all the positive energy (through Lithium ions). These ions then flow across the ̶o̶c̶e̶a̶n̶ electrolyte to the anode to charge it up with energy (through electrons).
Then, when the battery is discharging/being used, those electrons in the anode go out of the battery as electricity, do work, and then eventually come back to the cathode to start the cycle again. And that’s a battery explained with my Bob/Garry analogy!
So now, back to how great lithium-ion batteries are. How great a battery is changes based on its anode, cathode, and electrolyte. Usually, scientists find new materials to make these parts out of to change the battery’s cost, lifespan, energy storage, weight, etc.
Here’s a glance at current Lithium-ion batteries:
- They cost an average of $175 per kWh in 2018 — a kilowatt-hour (kWh) measures the amount of energy used in an hour. So it cost $175 to store one kWh of energy in batteries in 2018.
- A lithium-ion battery lasts 300 to 500 charge cycles — one charge cycle is when you fully charge and fully discharge a battery. So you can do that 300–500 times with current lithium-ion batteries before it wears down. For context, smartphones batteries need 300+ charge cycles to be efficient and electric cars need 1000+.
- It has an energy density of 100–265 Wh/kg today — energy density is a measure of how much the battery weighs compared to the amount of energy it holds. This is important for things like not having billion-pound laptops (or fancy electric airplanes)😉.
As you can see, lithium-ion is the current standard EVERYWHERE from cars to buses to electronic devices. But they also have problems:
- They’re still too expensive. If you think about electric cars not everyone can afford them and a big part of their high costs are the batteries. The Tesla Model 3 costs $35,000, for instance, and 25% of that is because of the battery.
- They give treehuggers a headache 🌿🥺️. Most lithium-ion batteries require rare materials like Cobalt. This is mined in developing countries like Congo, where not only is the environment harmed but also the poor locals working in dangerous conditions.
- There are also safety issues with lithium-ion batteries. Remember the Samsung Galaxies exploding??? The reactive chemicals used can really throw a tantrum in the wrong conditions (ex. overheating or physical impacts)
These are all problems waiting to be solved by the next battery innovation. lithium-ion batteries have been put to some pretty interesting uses, but what’s next for the future of batteries?
How Tough can Batteries Be??? Rock-SOLID
If you think back to the structure of batteries, remember how I compared the electrolyte to an ocean? That’s because it’s usually a liquid chemical that allows things like lithium ions to flow across. BUT that liquid isn’t very safe. It can leak out, react with the anode/cathode, catch fire, and generally make the battery more likely to explode… 😬
So to solve the safety issue of current batteries, scientists are trying to replace this explodey liquid electrolyte with a solid material instead. The reason liquid electrolytes have their safety issues is that the battery wears down over time. Cracks called dendrites start forming from the cathode to the anode. Once the two ends connect, you have the battery-explodey problems.
But if you have a solid electrolyte instead, these dendrites can’t get through from one end to the other. Problem solved! 🎉🎉🎉
Not so fast. The catch is that solid electrolytes aren’t great at transporting ions between the anode and cathode. So it’s been harder to make batteries efficient. That being said, here are scientists’ two main attempts:
1. Polymer-Based Electrolytes
The first type of solid-state battery works with polymers (long chains of molecules) as their electrolyte. Think polyethylene oxide with crystalline structures of [LiCF3SO2)2N](LiTFSI) alkali-metal salts. Y’know… those things:
These batteries are relatively new, but they’re starting to be rolled out commercially. France’s Bolloré has been a major contributor to this, with batteries for the energy grid and IoT sensors. Here’s a quick glance at the details:
- They say these batteries have a lifetime of up to 4000 charge cycles. Likely a bit embellished 😅, but solid-state batteries definitely last longer than current lithium-ion batteries (up to 500 charge cycles)
- Their batteries don’t use rare metals like Cobalt or Nickel.
- Each solid-state battery can store about 166 Wh/kg (compared to up to 265 Wh/kg for lithium-ion batteries)
There are still some key limitations here, however.
- First of all, it’s a little suspicious how Bolloré won’t list how much these batteries cost 🤐. That’s the biggest problem, because these new batteries simply don’t have the advantages of the economies of scale found with lithium-ion batteries.
- Then, there are also some limitations with the temperatures needed for solid-state batteries. While they do work in higher temperatures than current batteries, they’re not very efficient at transporting around Lithium ions at temperatures under 60° C. This limits the uses of the batteries — ex. you wouldn’t carry a portable heater with your phone 😄
- The batteries are harder to take apart and be recycled because the solid chemicals bond strongly to each other. This creates a larger mess to deal with at the end of the battery’s life — which is becoming more and more of a problem with electronic waste.
2. Ceramics-Based Electrolytes
Then, the second main type of solid-state battery is based on ceramic electrolytes (which sound very artsy!). Chemists like to refer to some as nitrided amorphous thiophosphate structures and others as LGPS-class ceramics. Y’know… those things:
The main advantage ceramics-based electrolytes have is that they can work at room temperatures, so they can be used by everyday people doing everyday things. Some more specialties are with how small we’ve been able to make them — they can ever power medical implants for years on end!
A major player in the space is Ilika. It’s working with Toyota to develop these ceramics-based batteries to extend the range and lifetime of electric vehicles. Currently, it’s developed microbatteries like with the medical implants. They’re also being used to power IoT sensors.
Overall though, it will still take a few years before we see the results of these developments. It’s harder to point out the specific numbers with this new technology as of right now.
So there’s a bunch of research being done in new electrolytes… but what about the other parts in batteries?
New Battery Anodes
Remember Garry from the battery analogy earlier? Sometimes, he can seem a bit unenergetic or slow, but it’s not his fault! Some people just aren’t able to hold that much energy and that’s okay. They just need to find the job best suited for them (I’m a qualified therapist apparently… 😄)
So what if we had someone besides Garry take over that job, while Garry did something more relaxing? Or in chemistry terms, what if we used another anode that could hold more energy? Currently, we use graphite — that boring stuff from pencils. It gets the job done, but it doesn’t hold that much energy:
Clearly, there’s graphite isn’t really the best at what it does… 😬 So if Silicon and Lithium are so great, how come we aren’t already using them??? As one of my heroes in the energy industry says:
“There’s always a catch…” — Michel Laberge
1. Silicon Anodes go Through too many Phases to be Reliable…
The biggest advantage of Silicon anodes is that they’re theoretically 25x better at holding energy (in the form of Lithium ions) than plain old Graphite. Even better, Silicon is found EVERYWHERE. It’s what sand is made out of. So if we made anodes out of Silicon… they wouldn’t be dirt-cheap, but they would be sand-cheap! 😁
Because of this, companies like Tesla are already adding some Silicon to their Graphite anodes… but it’s much harder to make an anode completely out of Silicon. The reason is that Silicon swells by up to 4x its original size when it holds Lithium ions. Imagine you turning on your phone and your battery suddenly changes shape!
The more serious part of this relates to the surface of the silicon anode. It forms a kind of rust (called the Solid Electrolyte Interphase) to protect the Silicon from reacting with the electrolyte. But when the Silicon keeps expanding and contracting, that rust breaks and some of the anode dissolves away. Eventually so much dissolves, that the battery doesn’t work anymore.
Companies have had to invent some pretty interesting ways of getting around this issue, but they’re also making fast progress. Take SILA Nano, for example. They take individual Silicon atoms and wrap them in a nanoshell that leaves room for expansion! 🤯 That way, the rust barrier between the anode and the electrolyte doesn’t break, improving energy density by 40%.
Enovix is taking another approach to the problem. They apply intense pressure to the silicon anode during manufacturing, decreasing the atoms’ ability to expand when absorbing lithium ions. The outcome is the same in that the Silicon has an increased lifespan.
Both companies have received support in their approaches. SILA Nano is working on applications for electric vehicles/airplanes, the energy grid, and consumer electronics. It even got $170M from the parent company of Mercedes to support this. Enovix is more focused on the electronics piece of the puzzle, with support from Intel and Qualcomm for its approach.
That being said, there are some major hurdles for these silicon-based anodes:
- These more complicated manufacturing processes inevitably increase the cost of creating battery anodes, although exact costs aren’t clear due to the limited commercialisation.
- Despite improvements in the durability, these batteries are still often limited in lifespan. Many start degrading in fewer than 100 charge cycles in research settings. (Current lithium-ion works for 300–500.)
Given the support this technology is gaining though, it seems like we’ll soon be using sand to build our castles and power them too (that’s my one and only cheesy anchorman pun for this article 😉)
2. Lithium is Like a Little Temper-Tantrum Toddler… 😬
Wait, weren’t we talking about lithium batteries this entire time? Yes, but those were lithium-ion batteries that had lithium in their cathodes. But there are also lithium-metal batteries that have anodes. Because what’s better at absorbing lithium ions than well… lithium!
While silicon-based anodes have shown increases in energy density of 40%, lithium-based anodes have increased the energy density by 100% to 400 Wh/kg! That being said, it’s pretty much the ONLY advantage these batteries have… 😕
Some of the headaches Lithium-based batteries cause for us:
- Since Lithium is reactive, it creates safety risks when exposed to water, nitrogen, OR oxygen (all of which are in our atmosphere). So if the battery was ever pierced or heated the wrong way, it’s explodey time. 🧨️
- Inside the battery, the lithium anode reacts with the electrolyte because it usually can’t form that ‘rust’ to protect itself. The durability is really low because of this (only about 50 charge cycles instead of 300–500).
- Dendrites form even more quickly with the anode and cathode both being made of Lithium. Explodey time x2 🧨️🧨️😱
A way to get around this was made by a company called Pellion. They were scrapped by Khosla Ventures in 2018, but they had proven that the technology works. They used a specialised charging technique to minimise how quickly the battery degraded. As I described above though, it still wasn’t very safe or durable (AND it cost more).
Pellion marketed these longer-life batteries (from the higher energy density) to the niche drone industry — where premium users would be willing to pay extra for the extra battery life. In the end, it didn’t work out for them because the biggest demand for batteries is in industries like electric vehicles.
That being said, the future of this technology isn’t completely dead. The notable exception is Sion Power, that is using Lithium-metal based batteries for electrical aircraft. It has set three world records for its unmanned aircraft flying solely on electric power and has partnered with Airbus to develop future electric aircraft.
In a quick glance at the details:
- The battery has an energy density of 500–650 Wh/kg, making it one of the lightest batteries ever (compared to 100–265 kWh/kg for lithium-ion batteries).
- It can achieve up to 450 charge cycles (within the 300–500 range of current batteries)
- Also, the UBER cool plane they built with Airbus just speaks for itself! 😎
*Sidenote: we talked about changing up electrolytes. We talked about future anodes. But what about the cathodes??? Actually, almost all our PAST battery research was to find new cathodes. You can see the progress we’ve made by doing that so far:
Basically, there’s a much greater potential for major improvements in future battery technology by changing the anode or electrolyte materials than from changing the cathode materials.
All things considered, there are lots of avenues of research in battery development. Most still need more proof before commercialisation on the scale of Tesla Gigafactories. And most still have common problems waiting to be addressed like:
- Dealing with end-of-life and e-waste
- And optimising manufacturing to decrease costs
But from the first battery-powered doorbells just 200 years ago to this world of ticking clocks, whirring computer fans, and bright desk lamps — we’ve seen amazing growth in this technology! These new iterations on it might just bring the next big jump forward, that makes us scratch our heads and rethink what we see as possible with battery design. So with all the potential paths forward, which of these possibilities is going to redefine our future?
- Current lithium-ion batteries have had a good run. But they’re too costly, damage the environment, and aren’t always safe.
- New electrolyte materials for batteries can increase safety and sustainability, but involve higher costs and sacrifice efficiency.
- New anode materials for batteries can increase efficiency and diversity of applications, but can be unsafe or hard to manufacture.
Before You Go
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