A Japanese and Australian team (Universities of New South Wales and Yokohama) has just announced that they have created a solid-state battery that they say is literally eternal. And now, a flashback.
This summer I considered with a bit of pride the fact that my smartphone was now almost 4 years old. Biblical Times Nowadays, Between Planned obsolescence and continuous updates, even minimal ones, which almost force you to change your device every 18 months (or less). I didn't really think about changing it, but one hot day in July the rear plate literally ejected in front of my eyes. Yes, ejected, like those jet pilot seats when one presses the button to escape with the parachute. Huh? Simple: the battery had swollen out of all proportion, causing the device to "explode". She could have caught fire, the repair guy told me.
Good. That is, bad. Because this is a fairly common occurrence, and probably many of you readers have experienced something similar. However, what is really worrying is the environmental impact of this poor battery life, especially now that we will be putting these things everywhere, in homes to conserve renewable energy and in practically all cars. The “Holy Grail” in this field is finding a battery that lasts much longer, and is much more stable. I have told you about many researches in this direction, and this one is incredible.
Okay, guys, you have my attention.
A premise before diving into this surprising research, to understand what we are talking about. Most of us use powered batteries from lithium ions, which have two electrodes (positive and negative) and a gelatinous electrolyte, as well as a separator in the center. This electrolyte allows the ions to Lithium to move between the electrodes, allowing the battery to store and release electrical energy. A solid state battery It works similarly, but uses a solid ceramic or glass electrolyte. These denser electrolytes allow solid-state batteries to hold more energy and be faster than lithium-ion batteries. For this reason, they are ideal for long-range electric vehicles, battery-powered aviation and even battery-powered ships.
And now, the weak point of both: duration. What happens? Why do these batteries “age” like this? I'll try to say it briefly. Sometimes, lithium ions in the positive electrode can attract and absorb “rogue” electrons, turning into deposits of raw lithium metal. This process can reduce the amount of lithium ions available in the battery, thus reducing its overall capacity. A bit like cholesterol plaques in an artery, then, if these lithium deposits build up (in spikes called dendrites), they can cause a catastrophic short circuit in the cell. It happens in lithium-ion batteries, and currently even more catastrophically in solid-state ones. Voila. And my phone is gone.
Yes, but the eternal battery?
Here we are. In the research just published in Nature (as always, I'll link it to you if you want to learn more: found here), the team announces that it has created a positive electrode so stable that it produces no lithium deposits, meaning that a solid-state battery using it will virtually never degrade. To prove it, they built a small 300 mAh cell and tested it repeatedly. After 400 charge cycles it still had literally the same starting capacity: proportionally it is as if a Tesla Model 3 LR had traveled 212.000 kilometers (132.000 miles) without losing its charge capacity. Usually, Tesla cells degrade by 12% after this distance, but this new electrode seems to promise a future with many, many fewer limits for our batteries. It opens up scenarios in which even a battery survives the life of the vehicle that hosts it, "migrating" to a new vehicle.
The implications: many and very important
Today, the production of electric vehicles and their batteries have a high environmental impact, including carbon emissions for production and the necessary extraction activities. However, with this new eternal battery, the electric vehicle industry would be able to become much more sustainable. This would open up large spaces for the second-hand electric vehicle market, as even those with high mileage would still be able to function properly. In other words, anyone, regardless of budget, could drive an electric vehicle.
What about mains batteries? They are currently a key pillar of renewable energy infrastructure, but their lifespan is limited. The cells work for about 20 years. At the moment, this is not a problem as no grid batteries are more than 20 years old, but when we start replacing them we will produce further carbon emissions and environmentally harmful mining. With a virtually eternal battery like the one presented in Nature, the life of grid batteries will be indefinite, and this will greatly reduce overall carbon emissions in the already greener field of renewable energy.
In summary: can this eternal battery change the world?
I would say yes, even if the word "eternal" sounds bad, and cannot be true. The current data shows us that after a sufficient number of cycles the battery has not moved one iota, but it does not mean that a battery will never exhaust its capacity. And in any case there are also other factors to consider: for example, how long does it take to charge a battery like this? How safe is it? How much will it cost. It's easy to say eternal.
Yet, even if we remain rational, there is reason to rejoice: if these researchers, as they announce, have found a way to make incredibly long-lasting and energy-dense batteries, the ripple effects of such technology will have a profound impact on our future, and about our efforts to save the world… from ourselves.
