In Simple Terms: Everything You Need To Know About Solid State EV Batteries

In recent months there has been much talk of so called solid state batteries for use in electric vehicles (EV’s).  However, most Solid State Battery engineering is not being done by the big automobile manufacturers like VW, Toyota and GM; mostly SSB’s are being developed by small design houses you likely have never hear of like QuantumScape, Fisker and Solid Power.

WHAT IS A SOLID STATE BATTERY?

When we think of solid state batteries, we think of electronic circuits with no moving parts.  For those of you with computer knowledge, and analogy would be spinning hard drives compared to SSD’s.  However that analogy is not fully applicable to batteries.

Put simply, Solid State Batteries (SSB’s) are just traditional batteries that contain no liquid.

Currently Lithium Ion automotive batteries have a positive (cathode) and a negative (anode) separated by a liquid (electrolyte).  That liquid allows the Ions from the lithium to move to from one side of the battery to the other while keeping the two sides insulated from each other.  If the two sides were to connect, the battery would short circuit and likely explode.  That would be very bad.

In contrast, Solid State Batteries have a solid membrane (plastic, porcelain, glass…) that separates the anode from the cathode.

WHY ARE SOLID STATE BATTERIES BETTER?

SSB’s are better than traditional batteries because they eliminate most of the space required for the liquid electrolyte making the batteries:

1. 25% to 50% smaller – this increases the much discusses weight to capacity ratio
2. Faster charging – at near the same rate as gasoline fills
3. Dramatically longer life – Telsa talks about a million mile battery but has yet to show it
4. Cheaper – They are simpler and eliminate the need for most of the tempurature management systems
5. Safer – If SSB’s overheat gaps in the solid state material between that allow the Ion flows melt and close eliminating most explosions

Well, those are the three big promises of SSB’s if anyone can get them out of the lab and scaled up to industrial volumes required by the automobile industry.

IS ANYONE MAKING SOLID STATE BATTERIES IN PRODUCTION VEHICLES TODAY?

Yes, Mercedes is manufacturing giant city buses named eCitaro G’s with Solid State Batteries:

“…Sep 16, 2020 – In the search for more powerful, faster-charging, longer-life batteries, researchers have set their sights on a technology known as solid-state, though conventional wisdom suggests this alternative to familiar lithium-ion batteries won’t make it to market until later this decade.

Apparently, somebody failed to tell Mercedes-Benz. The German manufacturer says it’s ready to launch the first production application of solid-state batteries in its new eCitaro G articulated bus. Eventually, the technology could wind up in Mercedes passenger vehicles, as well…” SOURCE

BMW, Ford and Hyundia/Kia have partnered with SolidPower is moving forward:

“…Jun 18, 2020 — Colorado-based Solid Power Inc. has started shipping its solid-state batteries to prospective customers in the auto industry for testing…” SOURCE

In 2018 Henrik Fisker held up a small pouch during a Fox Business interview and repeatedly said that his SSB was ready for production and could charge to 700 miles in just 1 minute:

He later walked that back to, it will be ready by 2020.

WHO IS MAKING SOLID STATE BATTERIES?

As stated many of the big automotive players are not making their own batteries so that gets to the question of who is working with who?  As of October 2020 here is a list of all the notable Solid State Battery matchups:

ARE SOLID STATE BATTERIES IN EV’s INEVITABLE?

SSB’s in EV’s are highly likely as there are a variety of well funded companies putting serious effort into them.  However there are nay sayers like former Telsa battery engineer Gene Berdichevsky:

“…After leaving Tesla, he started Sila Nanotechnologies and said SSBs are a ‘false hope.’ … Solid-state batteries face several technical difficulties that would be very challenging to overcome. Apart from dendrite formation, their solid electrolytes would be prone to micro-cracking, for example. There is also an issue with the investments currently being made.

All battery factories currently being built aim to manufacture regular lithium-ion batteries. Solid-state cells would probably require different machinery and building technics that would demand more investments should they prove to work.

In other words, as disruptive as lithium-ion cells were to legacy automakers and their investments in internal combustion engines, solid-state batteries would also represent a massive disruption on the investments currently made on regular lithium-ion batteries….” SOURCE

There are many other designs in play today like GM’s amazing Ultium battery which uses a flat pack design, 70% less cobalt, and is 35% less expensive than Telsa’s best battery.

As always the waiting for the future can feel painfully slow but that is what we are going to do as the chemistry and engineering wizards figure this one out.