Let's Save the Heros

The Heros

Monday, June 24th, at an Aricell plant in South Korea, the workers heard some popping noises, and saw smoke coming from a large stack of loose lithium metal primary cells, packaged in trays.? They immediately approached the stack and began removing trays, hoping to find the source and put it out, knowing that if a fire started, it would spread quickly and emit dangerous fumes and smoke containing hydrofluoric acid, among other things.? As they dug, there was more popping and smoke and eventually sparks and flames were shooting from the stack of batteries.? One of them got a fire extinguisher, and several others looked for ways to help, but lacking tools stood at a respectful distance, hoping for some way to slow the spread of the fire.? Eventually, the cells were going off like popcorn, and smoke filled the room beyond visibility, and beyond breathing.?

You can see the video of this here . ??While I can’t confirm, I would suggest that most of the people in this video are among the 23 people who died in the blaze that engulfed the entire factory.? A video of the factory burning is here.

For the last few weeks, I’ve watched these videos several times, and seen the bravery of the men and women who initially tried to fight the fire. They are trying to save their fellow workers, their plant, their company, their city.? What they had at hand as tools to help them is, frankly, pathetic.? Is there nothing that could have been dumped on the blaze?? A bag of something that could have been thrown at it?? Sprinklers overhead that could have released liquid (water?) to slow or extinguish the blaze?? Why were they left with nothing but a fire extinguisher, and many people standing around, wanting to help save their fellow employees, but not knowing what to do, or having the materials at hand to do it??

Below I will list these ideas and more, and then issue a call to action for the industry.? Please read on—if you want to help, you will be given an opportunity.

Tools for the Heros

I am not a firefighter and have no training.? But as a leader in a battery safety consortium, I have had the opportunity to have many conversations with firefighters, and with people and companies who are creating materials, tools and techniques that can be used to slow the growth or extinguish battery fires.

Battery fires are unique in that the electrical energy that is stored is VERY high and can come out VERY quickly.? Battery fires are rare, and this should be the context of the rest of this discussion.? It is not unsafe to work in a battery factory, or to have battery-powered devices in your home or on your person.? But when they do happen, they are IMMEDIATE and FEROCIOUS.? There just isn’t much time to react, once they start.

To put a time limit on it, from the videos I’ve seen, I’d say for any reaction to be effective, it has to take place within the first 30 seconds after the first flames, maybe 60 seconds on the outside.? Even that seems very long, so targeting the first 5-15 seconds would be ideal, or even before the fire starts. It would be even better if the solutions started before the battery reached full conflagration.?

As in all cases, safety is best achieved as a system, not a single silver-bullet solution.? Below is a list of ideas that could have been undertaken, attributed where I can remember to the source of the ideas.? I’ll start with the ones that can happen earlier. ?But very important:? this is not a list of single solutions, but rather a set of tools that could be combined to create a multi-layer system of fire prevention, protection and containment.

Also—where I have neglected to list your company’s solution, please add it in the comments so others may learn of your company’s innovations.

Sensors

My first conversations about sensors for lithium battery fires were (separately) with Brian Engle of 安费诺 and Randall Stacy of Nexceris .? Both are working to implement sensors that can detect and create alarms for battery packs, whether automotive or related to large energy storage devices.? Soteria is also developing a line of lithium-ion fire detectors based on gas sensors, which for industrial purposes will have Wi-Fi and Bluetooth capabilities. There are now many companies making sensors for early detection of lithium ion batteries, which detect signals that could be thermal, vent gases or other early indicators.

These sensors can give a very fast indication of the first venting, which can happen before there are flames and could give minutes of advanced warning.? These minutes can be crucial and allow for cooling, containment and other mitigation techniques.?

Protective Packaging (Passive)

The cells appear to be in open plastic trays, perhaps the worst possible packaging.? The explosive releases of energy in the video always happen due to failure of the separator and rapid release of the stored electrical energy, and this is caused by heat.? Once one cell goes off, the heat can propagate by convection, radiation or conduction.? These plastic trays may slow conduction, but convection and radiation are wide open.? And if something is going wrong inside a cell, there is nothing to keep the cell from overheating, where conducting the energy away from the cell can be a benefit.

Some possibilities for packaging are:

·???????? Thermally conductive containers that will propagate heat out of a cell.? This could be metals, or fluids in channels under and around the cells.

·???????? Closed containers, made of materials that inhibit radiation (metals)

·???????? Closed containers should have a gas vent that allows hot gases to get out, but directs them away from other cells.

·???????? Thermal insulation between the cells.

Companies with solutions in this area include 戈尔公司 , Kaneka North America , Mitsui & Co., Ltd. , KULR Technology Group, Inc (NYSE: KULR) , 杜邦 , Teijin Aramid and others.

Reactive Containers (Active)

Here I mean containers that react to something going wrong in a cell that they are holding.? They could respond to changes in temperature, voltage, pressure, or a gas concentration.? Here are some examples, but likely there are a lot more:

·???????? Heat in the package causes a membrane to melt or burst which releases a fire suppressant liquid, gas or solid.?

·???????? Thermal, gas or voltage monitoring triggers activated cooling and an alarm system.

·???????? Voltage monitoring triggers discharge of a cell that has aberrant behavior.

·???????? Voltage monitoring here could be done through flexible connectors, like the connectors in a flashlight or other disposable battery device.

Companies with solutions in this vein include CellBlock FCS , Labelmaster and others.

Sprinklers and Other Suppressant Release

A sprinkler system is obvious, but may not be enough.? I have seen a water mist system from Siemens , several different liquids and solids that have fire suppression capabilities.? They could be in fire extinguisher form or as part of a system that is activated by one of the sensors mentioned earlier.

Extinguishing Materials

There are many materials and techniques that are being promoted for fire suppression for lithium-ion batteries. These include:

·???????? Blankets, including those by Bridgehill , Brimstone Fire Protection , AVD Fire and others.

·???????? Powder and pellet materials, including those by Cellblock and DGeo and others.

·???????? Liquids, including those by Full Circle Lithium and others.

Having these nearby could have given those workers something to fight the fire with.

Personal Protective Equipment

Not one of the workers grabbed a gas mask, gloves, a flameproof coat, a blanket—nothing.? There are clearly solutions available today that—even if it didn’t stop the fire—given them time to get out once they realized it was helpless to fight.

Education

Watching the workers in the factory was, well, painful.? They clearly did not know what to do.? Should they leave?? Some were hanging back watching.? Should they fight the fire?? They had no ready tools except a fire extinguisher.? Was there any personal protective equipment, gas masks or the like, to help them breathe while they dug through the pile of trays?

A Call to Action

Over the next decade, there will be hundreds of new facilities built that will either manufacture batteries, or make things that use batteries for power.? If we don’t help them understand the range of protective strategies available, this scenario will repeat itself.?

Many of the ideas above are not good ones, and many of the best ideas are probably not in this post.? To help collect the best ideas, Soteria is going to organize a workshop on Lithium Battery Production Fire Safety, which will be both virtual and in-person, with a date to be announced soon.?

Wouldn’t it be better if, in the scenario we witnessed, the workers were first alerted by sensors that were detecting temperature and gasses, were able to respond by containing the aberrant pallet in a protective containment unit that is quickly filled with a cooling mist, while the cells are discharged and the pallet is able to be moved to a protective bunker where, once the system is cleared of any dangerous behavior through cooling, discharging and other systems, it can be sent safely to a recycling facility where the materials can be recovered and built into new, fully functioning batteries.

Lets work together to make this a reality.? Please comment below if you have a tool that can be part of a lithium battery production safety system, and like this post if you might want to participate in a workshop on the same topic.

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