Novel SSB Design Moves Towards Mass Production

Ally Winning, European Editor, PSD



Ally Winning, European Editor, PSD

I’ve been writing about battery technology for quite a few years now and it is one of the most fascinating subjects that I cover. There are so many researchers and scientists around the world innovating to overcome the challenges that they face to improve existing types of batteries or try to develop new ones. One of the most promising looking potential developments is the solid-state battery (SSB). It is usually based on Li-ion technology, but it has a solid electrolyte instead of a liquid one. In theory, the solid electrolyte offers many advantages. For example, it can’t leak, or burst into flame spontaneously like liquid ones can. To attempt to prevent those dangers, today’s Li-ion batteries are manufacturers in a thick metal casing, which makes them bulkier and more rigid than necessary. SSBs offer an alternative to liquid electrolyte batteries, that is smaller, safer and more flexible in shape. 

There are already plans to launch SSBs to the market, and several vehicle manufacturers have promised EV designs featuring SSBs in the next few years. However, there are a few challenges that remain before mass production. These challenges include dendrites, which are tree-like branches that grow between the anode and cathode. Dendrites can cause short circuits, or at best lower the efficiency of the battery. The solid electrolyte also expands and contracts while heating and cooling, which, in turn, makes the structure of the battery less stable, and could lead to separation of the anode, electrolyte and cathode. Normally, researchers physically ‘clamp’ their SSBs to stop the expansion. That, again, makes the batteries bulkier.

One company has taken a different route to SSB designs that overcomes this drawback and doesn’t require clamping. Maryland-based ION Storage Systems have designed a battery that features a combined anode and electrolyte structure, that is made from ceramics and resembles a sponge. The design is very power dense, and it also allows the cathode to be manufactured from a variety of materials, including cheaper ones, making it cost-efficient. The design also works well at both low and high temperatures, which is another drawback of liquid electrolyte Li-ion batteries. It’s a unique way of overcoming the problems faced by SSBs, and it could be available soon.

The company has recently announced that its SSB has had its first market deployment with the U.S. military. In tests, the SSB has exceeded 125 cycles with less than 5% capacity degradation, meaning that it has the potential for over 1000 cycles in future deployments. The cells are the first to reach this milestone with an anode less design and no compression. ION will shortly start mass production through a supply agreement and investment from Saint-Gobain. Initially, the company will continue working with the DoD to test the batteries before expanding into other markets.