The issue of safety in lithium ion batteries is an area of major concern that is generating a lot of interest in the media. And rightly so. Done right, lithium ion battery technology is a mature, well established technology that has been used for nearly 30 years. Done wrong? Well batteries have turned into incendiary devices and even bombs. So what is happening in the industry? Is the technology inherently unsafe, or are companies cutting corners to save costs or rush products to market? And what is the government doing about it?
The use of lithium batteries is booming. In Australia uptake of lithium batteries for home storage is higher per capita than anywhere else in the world, and larger commercial and even utility-scale projects are increasing at a rapid rate. Things are happening so fast that government regulation is struggling to keep up.
In 2017 Standards Australia had a go at a draft standard for battery installation and safety in residential installations. The whole issue proved a bit too complex so a blanket approach was taken that stated all lithium ion batteries could only be installed in stand-alone structures outside of the home. This potentially adds thousands of dollars to installation costs.
This led to uproar from industry and the Clean Energy Council, who claimed that the draft was too broad and penalised companies that invested in high quality, safe systems. Sonnen battery company has installed tens of thousands of systems in Germany in the last 10 years and never had an incident. The backlash prompted scrapping of the original draft and Standards Australia went back to the drawing board. However, Standards Australia is wrestling with the same issue as many potential customers: which is, how do we know if a battery product is safe?
Unfortunately, not all lithium battery systems are safe. The government in South Korea recently put a stop to all major lithium battery projects after 23 incidents were reported over two months. And this is South Korea, with Korean-based LG Chem, Samsung and Kokam some of the real powerhouses of the lithium ion battery industry.
Another example is lithium batteries that were put in Boeing’s Dreamliner aircraft in 2013. The US Federal Aviation Authority grounded the entire fleet, the first such grounding since 1979, after five incidents were reported over five days. The Dreamliners used batteries from a leading Japanese battery company GS Yuasa.
The Samsung Galaxy Note 7 proved a disaster for Samsung due to battery-related fires and it recalled the device not even two months after its release. Credit Suisse estimated this incident cost Samsung up to $17 billion in revenue.
When giant players like Samsung, LG Chem, GS Yuasa and Boeing can’t get it right, does that mean lithium battery technology is just too dangerous? Are even these companies guilty of cutting corners or is there a problem somewhere down the line with their use?
The reality is that lithium ion batteries are a mature technology and, when done right, are very safe. Since their commercial introduction in 1991 there has been literally billions of lithium batteries delivered to the market. Nearly all of these batteries haven’t had any problems. So how and why do things go wrong?
Where errors occur
As a senior engineer in Sony mobile put it, batteries fail due to one or both of two things: defects in battery manufacture, or; poor battery systems, including battery management and safety systems.
The Boeing incidents are a great example of this. The National Transportation Safety Board conducted an extensive investigation and found the fires almost certainly started from batteries with manufacturing defects. These were supplied by GS Yuasa in Japan, which didn’t have systems that could detect the defects. Also, Boeing’s system design failed to consider and allow for worst-case battery failures. Interestingly, the board also identified a failure by the FAA to recognise the potential hazard and institute proper tests as part of its certification process.
An industry expert remarked to me that the system design “broke nearly every rule in the book”. Most notably, toxic gases released from fire had nowhere to go but into the aircraft cabins. What a mess!
Similarly, the recent incidents in South Korea were also investigated. The preliminary findings indicate problems with battery management rather than the batteries themselves. No doubt this caused a flood of relief at Samsung and LG Chem.
With the Samsung Galaxy batteries, battery defects were a major cause of the problem. Samsung used its own batteries and batteries made by another company, ATL. Both caused problems, but with completely different faults. Samsung was also pushing the limits of cell design to maximise energy density, which can greatly exacerbate any problems in cells. Samsung learnt a lot from this and apparently has lifted its game, having been forced to build a new factory when their old one burnt down.
At the cell production level there is a gold rush happening that can result in less than perfect production. The number of battery companies in China has ballooned from a handful to several hundred in a few short years. No doubt many of these – some unwittingly, no doubt – are not achieving highest quality standards.
The problem is, it’s not so easy to set up a battery production line with sufficiently low defect levels to deliver adequate safety. It’s not just the first batch: companies are pumping out millions of cells per day, day after day, month after month, year after year. With so many cells being produced the defect level needs to be extremely low to achieve adequate safety. There aren’t that many people around with the experience and expertise to pull this off. Even if you do manage to snaffle a couple of these people to set up, once they leave quality can slide. An industry expert told me this is exactly what has happened with a couple of large Chinese producers.
Cell quality is a key issue. Cells from Tier 1 suppliers such as Sony/Murata, Panasonic (Tesla), LG Chem and Samsung should be OK. No doubt there are other good suppliers as well: it’s just that a typical customer doesn’t have the time, money or expertise to properly sort the good from the bad.
Then there’s battery management, which a former senior engineer at Sony told me is seldom done well. This is a real worry. The 23 incidents in South Korea were put down to poor battery management, and management was a key factor in the Boeing incidents.
Again, systems from Tier 1 producers, provided their own management systems are being used, should be fine. Also, companies like Sonnen, who do their own systems using quality Sony batteries, and have a long history of large supply with no safety incidents, can no-doubt be trusted. However, if you’re looking at a little-known Chinese brand of battery and the source of management system is unknown – well, take extra care.
The great shame seems to be that companies doing the right thing are being penalised along with those doing wrong. What a pity it would be if the critical role that lithium ion batteries can play in clean energy is torpedoed by lazy or nefarious operators looking to make a fast buck. Governments and regulators have a major role to play in making sure this doesn’t happen.
Geoff Edwards is the managing director of Excens Energy, which utilises battery systems and intelligent system design to maximise returns for renewable energy systems. He has more than 15 years’ experience in the lithium ion battery industry.