Breakthrough technologies -Lithium-metal batteries
2021 marked the 20year anniversary since the MIT started posting lists of technologies that could change the future. For technology freaks like us of course that means something: time for celebration! Why? Because every year, their list consists of technologies that can move the world forward and, equally importantly, it consists of technologies that we can look into and upon.
When technology is the main part of your day, your professional life and, let’s be honest, your hobbies, you strive to find the next big thing. The next “Computer” so to say.
In this series of articles, we’re going to take a look at some of the technologies listed as groundbreaking from MIT in this year’s list.
Shall we take a look at lithium metal batteries? Of course, we should because, as it is expected, they will change the course of electric vehicles and how efficient they can be.
What is the story here?
Till this day electric vehicles run on lithium-ion batteries. Breakthrough back in the day, still these batteries have a major flaw: dendrites. These thin, tree-like lithium pieces form sharp points that, in the long run, pierce the battery, causing problems such as short circuits. This, of course, makes the expiration date of a lithium-ion battery really short.
What is a lithium metal battery?
For that reason, scientists focused on studying lithium dendrite formation to see how they can make better, longer-lasting batteries for electric vehicles. Now, Harvard University researchers say they have found the solution: a lithium-metal battery made of a solid-state metal. Trying to get rid of dendrites, this metal will offer more structural stability to a battery, than any liquid or graphite materials.
Xin Li, associate professor of materials science at the Harvard John A. Paulson School of Engineering and Applied Science (SEAS) said that: “A lithium-metal battery is considered the holy grail for battery chemistry because of its high capacity and energy density.”
Li and his team managed to design a stable, lithium-metal, solid-state battery that can be charged and discharged at least 10,000 times — we’re talking about far more cycles than ever before — at a high current density. Then, the same researchers paired the new design with a commercial high energy density cathode material.
What does that mean in the real world?
10–15 years lifetime for an electric car, without the need to change the battery. That comes really close to the lifespan of a gasoline car, which is why we are talking about a breakthrough. Adding the high current density to the equation, we may have in our hands electric vehicles that fully charge within 10–20 minutes.
“Our research shows that the solid-state battery could be fundamentally different from the commercial liquid electrolyte lithium-ion battery,” said Li. “By studying their fundamental thermodynamics, we can unlock superior performance and harness their abundant opportunities.”
How did they manage to do that?
To stop the dendrites from doing their “dirty” work, Li and his team focused on a multilayer battery that puts various materials of varying stabilities between the anode and cathode. This multilayer battery prevents the penetration of lithium dendrites. It doesn’t stop them. It controls and contains them.
Think of a BLT sandwich-like battery. First, of course, comes the bread — the lithium metal anode — then the lettuce — a coating of graphite. Next step, tomatoes — the first electrolyte — and bacon — the second electrolyte. Last but not least, more tomatoes and the finishing piece of bread — the cathode.
Luhan Ye, co-author of the paper and graduate student at SEAS, said: “Our strategy of incorporating instability in order to stabilize the battery feels counterintuitive but just like an anchor can guide and control a screw going into a wall, so too can our multilayer design guide and control the growth of dendrites.”. To that, Li added: “The difference is that our anchor quickly becomes too tight for the dendrite to drill through, so the dendrite growth is stopped.”.
“This proof-of-concept design shows that lithium-metal solid-state batteries could be competitive with commercial lithium-ion batteries,” says Li. “And the flexibility and versatility of our multilayer design makes it potentially compatible with mass production procedures in the battery industry. Scaling it up to the commercial battery won’t be easy and there are still some practical challenges, but we believe they will be overcome.”
So, one thing is certain. Lithium-metal batteries could really be the breakthrough for electric cars and green transport in the following years. It could actually help many people make a change in their everyday life while helping the environment and that is exactly why it was on that MIT list.
How do you feel about groundbreaking technologies? Do you start your day wandering what the future will bring with the help of science and technology? Then you might just be one of us. Take the first step and check our openings here.
Sources:
https://www.popularmechanics.com/
