Battery safety education

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Battery safety education

Back in September of 2011, in Louisville, Kentucky, I attended my first industry conference, the NAATBatt annual meeting.  I was just getting started in the industry, and wandered around trying to remember what an anode and cathode were, and sifting through the alphabet soup of NMC, LFP, LCO, NMP, DEC, EC, LiPF6, PVDF and all the others.  There were about 50 people at the meeting, and they all seemed to know each other, and none of them knew me.   I remember Jim Greenberger sought me out, and welcomed me to the industry and asked how he could help me. 

Last week, there were 800 people at the 2024 NAATBatt Annual Meeting, a 16-fold increase, doubling 5 times in 13 years.  If this represents the growth of the industry—and I think it understates it—then our workforce is doubling about every 2.5 years or so, which would mean that 75% of our workforce has less than 5 years of experience.  Contrast this to my time in the textile industry, when I was still the “new guy” after 10 years in the industry.  I was being introduced as an industry veteran as soon as 2014, after only three years.

Before I go on, I’m going to give a shout out to five friends who took me under their wing and mentored me in the industry very early on:  Jim Greenberger, Shep Wolsky, Eric Darcy, Jim Kaschmitter, and Joe Turner.  Each of them taught me and introduced me and kindly corrected me and directed me and promoted me and the companies I’ve tried to create, and it’s hard to express the value of the mentorship that I’ve received from them.  Shep isn’t with us anymore, but I loved reading the comedic plays he wrote, and am sorry I never made it to Florida to see one of them performed.

Now for three somewhat funny stories, with a point at the end, I promise.  As an important disclaimer—do not try these at home, as you shall see.

  1. Joe Turner and K2 Energy had made some 26650 LFP cells for us using our Dreamweaver Gold separator. Knowing that the separator had great thermal stability, the first thing I did was put them into an oven, and crank up the temperature.  I went straight to 150 C, the max I’d ever seen any cell tested at before.  Sitting on the floor in front of the oven, with wires for thermocouples and voltage probes running into the oven and preventing me from closing it completely.  Nothing for an hour.  Okay, 160 C.  Same thing.  175 C, same thing.  Boldly, 200 C.  nothing happened for another hour—voltage stable, temperature stable.  220 C.  Again, nothing.  We’re onto something here!  240 C!  I sat back, expecting another hour of nothing.  I’d been sitting on the floor in front of the oven reading battery technical papers for most of the day.  Then, KABLAAAM, the oven door flew open, and bits of copper current collector and blackened Dreamweaver Gold separator drifted down from the ceiling like confetti.  Where I had been sitting, a bit of molten copper had melted through about a square inch of carpet.  But I wasn’t there because at the first sound I had scurried backwards like a crab on my upside-down all fours, crossing the room in about 0.5 seconds.
  2. Similar cell, but now the control (all normal materials and a plastic separator), about a year later, when Carl Hu, who became my co-founder at Soteria, and Tommy Yang, our intern, had set up a nail penetration test that we were going to conduct outside on a hot, humid South Carolina summer afternoon. We set the rig up, which used a lever arm to drive the nail in.  We drove the nail in and the cell immediately began to hiss and sputter, and then, BANG, it exploded and shot something projectile like into the air conditioner compressor unit, which was about 10 yards away.  The Freon-replacement spewed out in a white cloud, mixing with the humid air and making it snow.  Tommy saw the cloud and ran through our small lab out into the parking lot on the other side, while Carl and I just sat and laughed.  It turns out that the cell had a center pin in it, and when we did the nail pen, the energy release boiled the electrolyte and shot the center pin into our air conditioner.
  3. When the Samsung Galaxy Note 7 fiasco happened, I wanted to know what was inside and why it happened. So we bought a phone, and ran it down to zero battery.  Using a heat gun, we were able to soften the adhesive and get the phone apart, and then removed the parts that were above the battery.  I then used a flat plastic putty knife to gently lift the battery from the phone.  It immediately sparked, and as quick as I could slip on my hot glove and grab it and tear down the stairs, it was flaming in my hand.  I opened the back door and tossed it into the grass and watched it burn.  It turns out the dead battery still had some life in it.  Later, we bought another one and I repeated, except draining the battery to zero through a resistor overnight to get the voltage below 1V, after which I was able to get it open and have the insides inspected thoroughly.  But that will be another post.

Reading this, you might think I’m some klutz that shouldn’t be let anywhere near a lab, but instead I’m an experienced experimental physicist with over 300 patents to my name and a few billion dollars that have been sold using my inventions.  Rather, the stories are the confluence of three other pieces of information, namely:

  • Battery volatility: Thousands of scientists have put millions of man-hours into developing batteries that pack a lot of energy into a very small package, and it only a thin membrane that is holding all that energy back. The batteries are fine in their stability window, but outside that window, the energy comes out very quickly.
  • Probing the edges: As I was trying to understand the limits of safety in batteries, it left me constantly probing the edges of the stability window.  Nobody in their right mind would put a battery in an oven at 240 C.  No further comment. 😊
  • My ignorance: As a newbie in the industry, in a startup that I founded and which, obviously, offered no specialized safety training, I had no idea about the battery volatility, the stability window, and what happened at the edges of the window.

So, okay, I survived, and now Soteria uses explosion chambers with automated implements to probe the edges of the stability window, so it’s all okay.  Except that, as I started the article, 75% of the people in the industry have less than just a few years of experience, so there is an awful lot of additional ignorance out there. While some companies likely have a normalized training process, many do not, and new companies are being formed almost daily.  This all came to a head for me last week during Soteria’s inaugural meeting of our Battery Safety Education Task Force, which is discussing the idea of having a uniform set of safety training in the form of videos, documents, quizzes, etc., that can be used to give all of the new people entering the industry a fast way to get a baseline of knowledge.  Once I thought about it, I felt guilty for not having already done this ages ago.

Some of the baseline information that every battery engineer, technician, scientist or product manager should know includes:

  • Testing: What safety tests are there, and what do they mean?  How do you interpret the results to understand how safe a particular battery is?
  • Standards: What standards are there?  Does passing a standard mean a battery is safe?  For what applications and uses?
  • Procedures: What are safe procedures for handling batteries?  For handling battery materials? For running standard tests for batteries, such as electrical charge and discharge?
  • Safety events: How do you deal with a safety event?  If something catches fire, do you just pull the fire alarm and get out, or is there something else that should be done first?
  • Safe design: How do you design a battery for safe?  What specific conditions of the use case need to be considered when deciding what safety strategies to take?  How much can be done through BMS, through packaging, sensors, cooling, and other mitigation techniques.
  • Laboratories: What laboratory equipment should be present for safety?  What does a safe lab look like?
  • Personal protective equipment: What PPE is necessary for handling batteries, for storing them, for transportation?
  • Transportation: What is required for safe packaging and transportation of advanced batteries?
  • Disassembly: How can batteries be safely disassembled?  How should the batteries be prepared for disassembly?  What is done with the materials afterwards?
  • Commercial Incidents: If there is a commercial-scale incident, what should be the response?  Is evacuation necessary?  How about cleanup of the materials and debris afterwards?
  • Legal aspects: What are the legal aspects of product safety, commercial incidents, etc.?  How can a company properly prepare to mitigate or control liability, while also being a responsible citizen.
  • Root cause analysis: Once an incident occurs, how can one determine the root cause? 

When I read this list, I get shivers about all the things that very good, competent or even excellent engineers who come into the industry from another industry, or straight out of school, do not know.  To help this, Soteria is partnering with InnoEnergy and the other members of the Battery Safety Education Task Force to create content for a Battery Safety Certificate which can be earned by successfully going through the content.  There will be modules on all of the above, and whatever else the Task Force deems necessary.

If safety in your work with batteries is critically important, or if you want to get involved in guiding the creation of the content above, please reach out to Amy Brinson, our VP – Global Consortium, to learn how you can join the Soteria BIG consortium and get involved in the Battery Safety Education Task Force.  We’ll certainly let you know when the material is finished and becomes readiAbby Zielsdorfly available, which we expect to be by the end of 2024.

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