The battery technology that could put an end to battery fires

Stop me if you’ve heard this one before, but there’s a battery revolution coming. No seriously, this time, like, really. For a quick reality check to demonstrate why solid-state batteries are the future, consider this: if the Galaxy Note 7 (and some iPhone 7s) that have been exploding recently had been using a solid-state battery, we might not have the glorious memes and witty presidential banter we currently have.

Solid-state battery tech, to give you some background, is nothing new. In fact, the first devices to use solid-state batteries were pacemakers. Solid-state electrolytes, primarily used in thin-film batteries, are already being used in IoT, RFID and wearable devices. But it’s actually the reason they are being used in these devices that explains why we haven’t seen them in smartphones yet.

Long story short, solid-state electrolytes are much safer than lithium ion batteries that rely on liquid-based electrolytes (like essentially all smartphones right now do). They have higher energy densities and longer life cycles than traditional lithium ion batteries too. That’s why they’re used in pacemakers.

An expensive necessity

But solid-state electrolytes are expensive to make. As Dr. Lorenzo Grande, a technology analyst at IDTechEx, who will present a webinar on solid-state battery tech on October 25 (details here if you want to listen in), told me, the “cost per square meter increases exponentially with the size of the battery you want to make.”

The cost for a thin-film battery could be $20-30 for a small RFID, but the cost would be prohibitive at smartphone battery levels. At that scale a solid-state alternative could cost thousands of dollars for a single battery.

This is clearly a barrier to mainstream consumer electronics applications. But as Dr. Grande pointed out, referencing current events:

Lithium ion batteries as we know them contain flammable electrolytes. These electrolytes are typically made from organic substances or chemicals that are highly flammable.

When we consider replacing these electrolytes with a solid counterpart the immediate benefit is the switch from a flammable liquid to something solid which is either not flammable or is much less flammable and therefore safer for the user.

The reason why everyone is using liquid electrolytes is because solid electrolytes are either not fully developed yet or are still too expensive to manufacture on a large scale.

That said, it’s clear that solid-state batteries have a great future in consumer electronics ahead of them, just as long as we can get the cost of manufacture down. Although it’s still very much anyone’s game, Dr. Grande thinks that a company like Samsung, which has suffered immense damage to its safety reputation recently, might be among the first to announce a solid-state battery in a smartphone, even if it costs them money to do so.

Where we’re at

As Dr. Grande told me, the majority of companies making the news in the solid-state and alternative battery tech world (like Enevate, which has a silicon lithium-ion battery due out any day now), tend to be the small startups that need the publicity. And yet, even Enevate is open about the costs involved in alternatives to what we have now, admitting that performance scales with price, so a high performance battery still has a relatively high cost.

But just how advanced the research into solid-state electrolytes is at major companies like Samsung and LG, who produce both batteries and consumer electronics, is much harder to gauge. What the current market leaders in mobile battery tech have achieved behind closed doors could be very advanced, but for competitive reasons they don’t publicize it.

Nevertheless, a researcher like Dr. Grande firmly believes that in the next few years, liquid-based electrolytes in lithium ion batteries will be a thing of the past: “The solid-state battery market is poised to be a game changer in the field. The company that manages to capture the value chain behind solid-state batteries will generate a reshuffling of the main market players.”

Naturally, Asian battery companies have a strong interest in maintaining their dominance but there has been a lot of interest and investment recently in the U.S. and Europe. Depending on who defines the dominant technology, and who manages to do so in a cost-competitive way, the current market leaders might lose a significant amount of their market share to solid-state batteries in future.

The reason things are so ill-defined right now are because there are around eight different categories of solid-state electrolytes that could be used in mobile electronics. Each electrolyte formulation has different benefits, meaning each type will be more or less applicable to a market depending on its particular priorities.

Benefits of solid state

So what are the main benefits to solid-state batteries? Safety is high among them, with solid-state electrolytes being not only less flammable but also more stable and less prone to the thermal runaway that results in battery explosions.

But solid-state electrolytes are also less reactive than liquid ones, so they can be expected to last a lot longer. Solid-state batteries also allow for increased energy densities, “up to two times the current values if these batteries also have the graphite anode replaced with a lithium metal anode”. Increased safety, combined with longer life spans and higher capacities make for a pretty compelling sales pitch.

But how manufacturers will choose to roll out solid-state batteries is anyone’s guess. Manufacturers may choose to keep the physical size of a battery the same size as they are today, with greater battery life as the benefit. Or they may choose to reduce the overall size of the battery while maintaining the existing “all day” battery life we’re accustomed to.

This may seem like an obvious choice – who wouldn’t opt for a phone marketed as having 2-3 day battery life? – but remember that solid-state batteries are expensive to produce.

This means we’re more likely to see smaller solid-state batteries introduced first with battery life similar to what we’re getting from existing liquid-based electrolytes. At least until the cost of manufacturing solid-state electrolytes can be brought down.

When will it arrive?

So when can we expect to see solid-state batteries take over? According to Dr. Grande, the automotive industry is the ultimate end game. That means the auto industry will have to wait the longest due to its stringent safety requirements. But that means other fields can be expected to see solid-state batteries rolled out much earlier.

“The drone market is in many ways an initial step for the next generation of solid-state batteries,” Dr. Grande says, “and this will happen as early as 2017. The second market would be wearables and then larger consumer electronics like smartphones. But this technology won’t really be mature enough for the mobile phone market for another 4-5 years.”

Even with this rather familiar-sounding timeframe, solid-state electrolytes in batteries – or another new battery technology – is long overdue: “Lithium ion is nearing its technical limitations and the liquid electrolyte is one of the reasons for that. Once solid-state electrolytes are enabled in the drone market and consumer electronics market every company will see the added benefits of using this technology to make better batteries.

Final word

As always, the problem is cost and mass adoption. The initial investment costs are still high and we’re still waiting for the mainstream mass production model to be defined. But once a company like Samsung decides to take the plunge in a consumer product, the massive increases in production volume will help to drive manufacturing costs down.

“What major battery manufacturers have done so far is to do damage control, i.e. add a flame retardant to a liquid-based electrolyte. However, there is no silver bullet in this respect. Battery manufacturers have been adding additives for years now, but as you can see from the [Note 7] news, bad things can still happen.”

Solid-state may be the future, but as Dr. Grande warns, “we’re still not sure which of these technologies will make it to the mass market.” It also has to be admitted that “what’s out there right now is not on a par with the performance of liquid electrolytes”. But as the technology reaches maturity, there’s little doubt that solid-state will take over.

Do you like the sounds of solid-state batteries? Do you think this could help Samsung’s image?

If you would like to join Dr. Lorenzo Grande’s webinar on solid-state batteries for IDTechEx, click here. There are multiple sessions on October 25.