Solid state batteries and new NASA technology: Are the days of flammable Lithium-Ion soon over?

For decades, lithium-ion batteries have been serving as the "gold standard" in energy storage. They power our smartphones, laptops, and increasingly, our cars. However, lithium-ion batteries degrade quickly, and they are flammable. So what about Solid State Batteries?

The energy density of lithium- ion – meaning the amount of energy they can store relative to their size / weight  – leaves much to be desired, writes the Polish space company TS2.Space on their website. 

The answer may in the future be solid state batteries : they are safer, lighter, more powerful and more durable.

Sounds too good to be true? Well, yes - while we are likely a few years away from a commercial breakthrough, some believe the batteries are already almost ready for a technical application in areas of transportation where fire is a particular problem, like in aviation. 

So what is a a solid state battery?  According to Wikipedia,  a solid-state battery deploys solid-state technology using solid electrodes and a solid electrolyte, instead of the liquid or polymer gel electrolytes which are used in lithium-ion or lithium polymer batteries.

While solid electrolytes were first discovered in the 19th century, several drawbacks have prevented widespread application. Developments in the late 20th and early 21st century have caused renewed interest in solid-state battery technologies, especially in the context of electric vehicles, starting in the 2010s.

Solid-state technology batteries can provide potential solutions for many problems of liquid Li-ion batteries, such as flammability, limited voltage, unstable solid-electrolyte interphase formation, poor cycling performance and strength.

Can Solid State Batteries replace our flammable and aging EV-batteries? 

In their article "The Rise of Solid-State Batteries: Outpacing Traditional Lithium-ion Powerhouses", the company describe "solid state batteries" as a new and potential competitor to lithium-ion, once the technology becomes commercially viable: 

"Firstly, solid-state batteries have a much higher energy density than lithium-ion batteries. This means they can store more energy in the same amount of space, or the same amount of energy in a smaller space. For electric vehicles, this could translate into longer driving ranges and smaller, lighter batteries. For portable electronics, it could mean thinner, lighter devices with longer battery life...

... Secondly, solid-state batteries are safer. The liquid electrolytes in lithium-ion batteries are flammable and can cause the battery to explode if it overheats. Solid electrolytes, on the other hand, are not flammable and can withstand higher temperatures. This makes solid-state batteries less likely to catch fire or explode". 

Still too expensive for most commercial uses... but perhaps not all

However, there is a catch: Solid state batteries are not commercially viable yet. Or, yet in simpler layman´s terms: Solid state batteries are still too expensive for most consumer applications, including exclusive EVs.

However, some recent research is promising:

The Massachusetts Institute of Technology (MIT) has recently developed a new type of solid-state battery that can operate at room temperature and has a lifespan of more than a decade.

A team of scientists at the University of Michigan has discovered a way to make solid-state batteries more durable and less prone to degradation. Read more

NASA developing solid state batteries for aviation 

The science website CleanTechnica.com writes in a recent article about NASA´s development of a Sulfur Selenium Solid-State Battery light and strong enough to power large airplanes. 

"Most of us have little idea what NASA — the National Aeronautics and Space Administration — has been doing since the Apollo moon missions ended... It turns out, the “aeronautics” part of its mission includes advances in airplanes, and that means finding alternatives to conventional fuels that will leave fewer emissions behind during flight", CleanTechnica.com wrote in July 2023. 

According to the article, NASA has for years been researching battery-powered flight as part of its Solid-state Architecture Batteries for Enhanced Rechargeability and Safety (SABERS) program:

"NASA says its sulfur selenium prototype battery has an energy density of 500 watt-hours per kilogram, which is about double that of conventional lithium-ion batteries". 

The problem is, aircraft need enormous amounts of power to lift the ground. And until recently, lithium-ion batteries were able to discharge their stored power much more quickly than solid-state batteries could.

Ahe SABERS researchers, with help from partners at Georgia Tech, now claim to have found a way to make their solid-state batteries discharge ten times faster than when the research started. Then they achieved another five-fold increase after that - and that is in a battery which is 40% lighter than the same energy stored in a lithium-ion battery. 

Again, currently the problem for these batteries to enter the market is cost. For most large passenger vehicles and personal vehicles, the costs will likely be a barrier for several years. However, for airlines, air taxis and other applications where the costs cold be spread out over thousands of flights, the  economic threshold may perhaps not be too far into the future.

The article mentions two air taxi companies currently considering the new batteries:

United Airlines  uses winged aircraft that need less power to stay aloft once they reach cruising altitude. The other, from Archer Aviation, uses what are basically enlarged drones that need their rotors to be in constant high power use in order to stay aloft, which means they use lots of power all the time and have a shorter range.

Photo Credit: (Cover photo above) 

A solid state battery diagram. Wikipedia Commons License, authored by Na9234. 

So what