24 Dec 2019
Current Affairs and Battery Life Prove the Talk of Detroit Showcase
The challenges involved with contemporary storage cell development were just some of the many things laid bare at Detroit's recent Battery Show, although didn't stop some of the more evangelical exhibitors making rather bold claims…
With energy-storage development viewed as slower than other technologies, the battery industry is still waiting for its next big breakthrough, according to some at Detroit's Battery Show. While a handful of exhibitors caught the eye with potentially revolutionary – albeit still nascent – new battery systems, much of the focus at the event was on wringing the last drop of performance out of existing cell chemistries and mitigating their shortcomings.
Steven Butzen, Regional Sales Manager for Wisconsin-based firm Fedco Batteries, summed up the general mood. "Battery technology is growing, but very slowly as far as the capacity per volume goes," he said. "The next breakthrough might be years away." To a greater or lesser extent, the majority of exhibitors at the event seemed to be looking for ways of using existing battery technology to its fullest potential, or to repurpose proven cell chemistries for new applications.
Martin Smego, Regional Sales Manager, Midwest USA, for Illinois-based Alium Batteries, was one of many at the event to talk about how alternative cell formulations can deliver improved performance. "For sealed lead acid replacement, lithium iron phosphate is the chemistry that people are gravitating towards," he said. "The price point is times two or three, but it lasts 10 times longer and gives you more capacity, so it's a value proposition."
The greater initial capital outlay may potentially deter some customers, but Smego saw the benefits as outweighing the drawbacks, saying: "That thing there that looks like a car battery, you can buy that for US$100, but for us it's going to be $350. A lead acid car battery you have to replace every two to three years; but that'll last for the life of the car."
Alium has experienced good business growth in specialist applications such as wearable technology, which place unique demands on cell design, having to minimise weight and maximise capacity while being shaped for wearer comfort. "There are only a handful of people in the world who can do a shaped lithium polymer cell; it's usually for wearable tech," said Smego.
"We have a curved battery that we did for Bose because they wanted to optimise their space. Usually with lithium polymer, they're prismatic or they're rectangular, so you're stuck from a mechanical standpoint."
Another exhibitor repurposing existing technology was New York-based Urban Electric Power. A recent start-up, the company is seeking to break into the growing home energy storage market, offering an alternative to the high-profile Tesla's Powerwall. Ann Marie Augustus, Vice President of Operations, explained: "We are working on a rechargeable zinc manganese dioxide system. You're probably familiar with that type of chemistry in a primary battery, like Energiser or Duracell – the same chemistry as in your remote control or children's toys, but our innovation is the rechargeability."
The advantage for home power storage is twofold, as Augustus explained: "Generally, alkaline chemistry is better from a safety perspective. For residential applications, you may have some concerns about putting a lithium ion system in your garage because of flammability, but alkaline chemistry doesn't have any of that.
"It also has some very good cost advantages. Zinc and manganese dioxide are very abundant; there's an existing supply chain in the primary battery market and we are able to tap into that."
There are certain drawbacks with the Urban Electric system, but these are of little concern in spacious US homes. Augustus said: "We're not at the same capacity that lithium is; that's still more energy dense. But for a battery you want to be safe and it's okay if it's the size of a small refrigerator because it can go in the garage; then I think the alkaline chemistry can still be competitive."
As ever greater demands are placed on energy storage, the technology's performance is pushed to the limit – sometimes with disastrous results. A series of high-profile failures has, in recent years, awakened consumers and regulators to the dangers of batteries overheating and catching fire, whether in smartphones, vaping devices or on airliners.
Tackling this overheating problem was the main focus of several exhibitors at the event, including Chicago-based Allcell. The company's Chairman and CEO, Said Al-Hallaj, said: "We make batteries safe. We have a technology called Phase Change Composite – which is a fancy way of saying graphite and wax, like pencil and crayon – which you put the battery in. The material is designed so that if one cell fails it will melt very quickly and the wax will absorb it like ice in lemonade."
Although the technology was developed for the military, the company was targeting civilian customers in Detroit. Al-Hallaj said he believed that applications where a safety certification is mandatory represent the best prospects. "Our best market is for customers who need to pass safety requirements. They need to demonstrate that the battery has a failsafe so there is no thermal runaway propagation.
"For example, if you put a battery in a certain application and you require UL [Underwriters Laboratories] certification. One of the tests is a thermal runaway. That's for automotive, aerospace for sure, medical."
As well as tightening controls around battery use in certain applications, how battery-powered products are distributed is also a concern. This is especially relevant to e-commerce business models distributing goods through postal services. Butzen of Fedco Batteries said: "You could take this one cell and put it in UPS. If you put two cells together, now you've got a battery pack, and that has to be certified to UN38.3 for transportation, which is a range of tests including altitude simulation, shock, vibration, thermal and so forth in order to just put it in the mail."
While the general trend at the show was towards mitigating safety risks, repurposing existing technology to new applications and squeezing out the last bit of performance, there were some signs of potential breakthroughs. One exhibitor hinting at game-changing technology was the somewhat guarded Salil Soman, Vice President of BrightVolt, a firm based in Washington state.
Soman said the company had developed a revolutionary approach to battery design and manufacturing that made its lithium-polymer batteries safe, explaining: "The solid-state polymer is replacing electrolytes in lithium ion batteries. Applications are where safety is an issue, such as automotive and aerospace. We can't say who we're talking to, but we've had interest from every major player."
Another exhibitor rather more open about his firm's ground-breaking technology was David Grant, President of the California-based Battery Streak. Grant made some bold claims for his company's offering, saying: "We make very fast-charging batteries – they charge 20 or 30 times faster than your cell phone and they don't get hot.
"We have an example here that's at the end of its charge cycle, so it should be at its hottest, but it's not even at body temperature. It charges in under 10 minutes and that applies to power tools, cell phones, and some day your car, which will literally charge in under 10 minutes."
Such a radical performance advantage involves very different technology. Grant explained: "It's a nano-structured material. Think of it as a sponge where the pores are in the order of 20 to 50 nanometres – a human hair is about 200,000 nanometres. That makes a very close relationship between the electrolyte and the electrode, so the ions don't travel very far.
"The second part is that when the ions do travel in or out, the energy storage mechanism is a surface charge – like a capacitor. There's no chemical phase change that generates heat – which is a problem, and also wears on the material. So, because there's no phase changes we don't have the heat, we don't have the material wear. You get very long life cycles."
Predictably, there are some compromises compared with current batteries. Cost is currently very high – about $1,000 per unit – but the company is still at the start-up stage and yet to benefit from economies of scale. Another drawback is energy density, as Grant outlined. "Physics never gives you anything for free, so the one drawback is that our energy density is about half that of a traditional lithium ion battery," he said. "So, we're looking at applications where battery size is not so critical, but charge time is, like when something needs to run 24/7."
The 2019 Detroit Battery Show took place from 10-12 September at the Suburban Collection Showplace.
James O'Donnell, Special Correspondent, Detroit