New Lithium-Ion Battery Woes | January 28, 2013 Issue - Vol. 91 Issue 4 | Chemical & Engineering News
Volume 91 Issue 4 | p. 7 | News of The Week
Issue Date: January 28, 2013 | Web Date: January 25, 2013

New Lithium-Ion Battery Woes

Safety: Airplane battery fires thrust electrochemistry safety back in the spotlight
Department: Science & Technology | Collection: Safety
News Channels: Materials SCENE, Environmental SCENE
Keywords: Lithium-ion battery, 787, battery fire, battery safety
Li-ion battery units power various systems on Boeing 787 Dreamliners. Two cases in which these batteries recently caught fire have led airlines to ground the wide-body jets.
Credit: Boeing
Li-ion battery units power various systems on Boeing 787 Dreamliners. Two cases in which these batteries recently caught fire have led airlines to ground the wide-body jets.
Credit: Boeing

Questions about the safety of using lithium-ion batteries for transportation applications have hit a zenith with two incidents in which such battery units onboard Boeing 787 Dreamliner airplanes caught fire or began to smolder. Airlines worldwide have grounded the new wide-body jets pending the outcome of investigations concerning the batteries and supporting equipment.

Boeing says the batteries on its 787s feature multiple backups to ensure safety, including protections against overcharging and overdischarging. It has declined to comment on the investigations.

Li-ion batteries can pack more energy into smaller and lighter weight units than other types of batteries. Those attributes have spurred enormous growth in their use for cell phones, laptop computers, and other portable electronic devices. Boeing selected the low-weight, high-energy-density batteries for the 787 Dreamliner to help reduce the new jetliner’s overall weight and bulk and thereby increase fuel efficiency.

A downside of Li-ion cells, however, is that they contain a flammable electrolyte solution consisting of lithium salts in organic solvents such as ethylene carbonate and ethyl methyl carbonate. This is not the case for other commercial battery types.

This burned out unit comes from a Japan Airlines plane.
Credit: NTSB
This burned out unit comes from a Japan Airlines plane.
Credit: NTSB

In Li-ion cells, heat generated by an internal or external short circuit, abusive electrical conditions, or other sources can, under some circumstances, ignite the battery liquid or rapidly raise its vapor pressure until the cell bursts, says Daniel H. Doughty of Battery Safety Consulting in Albuquerque, N.M.

Reports of fires in portable electronics caused by Li-ion batteries led manufacturers to recall millions of laptop batteries several years ago. The news shoved Li-ion battery safety issues into the spotlight. The recent incidents with the 63-lb battery units onboard Boeing jets have grabbed headlines in part because of the obvious difference from laptop computers in scale and potential danger.

Investigators have not yet determined the cause of the Boeing battery pack incidents that occurred earlier this month. In one case, a Japan Airlines (JAL) 787 Li-ion battery that powers the plane’s auxiliary power unit caught fire on Jan. 7 as the empty plane sat on the tarmac at Boston’s Logan International Airport. In the other incident, All Nippon Airways (ANA) pilots made an emergency landing in central Japan on Jan. 16 because of alarms warning of an electrical problem and an unusual odor in the 787’s cockpit. Both the alarm and the odor were traced to a damaged Li-ion battery.

The U.S. National Transportation Safety Board has ruled out excess voltage as the cause of the JAL fire. The agency says examination of flight recorder data indicates the auxiliary power unit battery did not exceed 32 V, the designed operating voltage.

Likewise, Norihiro Goto, Japan’s Transport Safety Board chairman, says flight recorder data show that the ANA battery’s output voltage was normal before alarms sounded in the cockpit.

Brian Barnett, a battery safety specialist at Lexington, Mass.-based technology development firm Tiax, says safety risks can be minimized with electronics to monitor battery performance.

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Jason  (February 9, 2013 5:44 PM)
In the dozen or so articles about this incident, their is one piece of information that is missing that could be critical to the long term solution of this kind of problem. No where have I found which kind of Li-Ion battery technology is being used.

Some Li-Ion battery chemistrys are much more suseptible to catastrophic failure than others.

Maybe someone should, during the next press conference, ask the question: "Which Li-Ion" chemistry is currently being used, and if the answer is anything other than "Li-Ion Phosphate" (LiFePO4), suggest that maybe they should contact a company named A123. They are one of the leaders in developing the safer LiFePo4 technology.

A quick web search would reveal a wealth of information reguarding the industries efforts and success in developing this kind of safer Li-Ion battery technology.

Fly Safe
david pacholok  (February 24, 2013 2:40 AM)
The LiIon chemistry selected by Boeing is of the CoO2 cathode chemistry. This chemistry has nearly the highest exotherm Joule release of any current system. Unfortunately it has among the highest energy density among the same systems, and was one of the first chemistries to win widespread adoption. You are correct, LiPO4 and Li-Mg-PO4 (Valence)seem to be far more abuse tolerant, and generally safer. Their cathode exotherm is quoted at 5-10% that of CoO2 or mixed oxide systems. They certainly survive the "nail intrusion" and "bullet" tests a lot better than oxide systems if one can beleive mfg's hype, and somewhat rigged(?) tests.

Now Boeing isnt stupid, nor is Securaplane or Thales (contractors for 787 aux power systems), although, it certainly apears so. We may ask: HOW DID THE WORST POSSIBLE CHEMISTRY IN TERMS OF FIRE SAFETY WIND UP ON THE 787?

I dont pretend to know the reasons, but I find it interesting that the battery manufacturer GS-Yuasa is a Big Jap Battery maker, and not ONE but TWO Jap airlines happened to buy 787's. I am not making accusations of any kind here, but every country wants to have as much as possible DOMESTIC CONTENT in the products they buy, the USA is no exception, and I see nothing inherintly wrong with this.

GS-Yuasa happens to have "aircraft-qualified" Li-CO2 batteries available, the decisions were made, and the rest is history, as they say. Fortunatly no one was seriously injured or killed before the problem came to light.

Hopefully no GS-Yuasa execs are planning to commit Sepiku.

David Pacholok
Power Electronics Engineer
Charles Gay  (February 10, 2013 1:06 PM)
I'm neither a chemist or an engineer, but in the past 40 years since lithium ion batteries emerged, has anyone considered the possibility that in, connection with both laptops and aircraft fires, there might be something other than a mere chemical reaction going on here? There is, after all, such a thing as cold fusion. Typically, cold fusion is considered to take place in the presence of hydrogen and electricity, causing the fusion into helium to occur, but who's to say that it can't take place in the presence of lithium and electricity. One has only to recall, that in early test versions of the hydrogen bomb, at Eniweitock in the Pacific, that lithium was included in the components of the H-bomb, and ALL the experts agreed that the lithium would NOT take part in the fusion reactions. However, when the bomb was detonated, the yield was estimated to be several times what would be expected if only the hydrogen itself participated in the reaction. It is also worth noting that all modern fusion bombs involve the use of lithium hydride.
Lin  (February 21, 2013 1:25 PM)
This is an excellent point!
I remember a documentary about that H-bomb test and how it was at least 10 times greater than they anticipated.
And there's SO much of EVERYTHING that turns out we don't know squat about.
Robert  (June 17, 2013 6:54 PM)
It’s easy to armchair quarterback the design and design decisions after the fact. The suggestion of using LiFePO4 is poorly considered.

While LiFePO4 cells are inherently safer than other chemistries, the energy density of these cells is much less. Given the application is for an aircraft, I am sure weight of the pack was an important consideration and it is probably for that reason that LiFePO4 was not chosen.

While minimizing weight is important, it is obvious that safety of the pack must be the highest priority. The data I have seen indicates the pack voltage was within norms, but when dealing with high series cell count, pack voltage is not the best indicator. To understand the pack condition, cell voltage for each cell needs to be known. Some commercial safety and dgas gauging solutions offer a “black box recorder” function to measure pack environment lifetime maximum and minimums, like temperature, charge and discharge current etc. If these quantities were recorded, it should greatly

There are many techniques for providing adequate safety to prevent this type of event from occurring. I have designed many battery packs with different variants of lithium chemistry and while the cells may change, the electrical design elements that I use to ensure safety, rarely do. In certain applications, like medical devices, its necessary to add safety systems that meet stringent agency demands, like UL2054, but that isn’t driven by the cell, its driven by the application.

The bottom line here is that a properly designed system can be made to be safe, regardless of the fact the cells are CoCO2. There are a handful of critical safety features a pack should include to prevent this type of issue from occurring.

1)Over current in both charge and discharge
2)Over voltage in charge
3)Under voltage in discharge
4)Over temperature in charge and discharge
5)Under temperature in charge

If these key items are controlled to within cell spec limits there is almost no chance of a pack incident. The only thing left really is internal cell faults, and for that, no safety system can stop the cell from going into thermal runaway.

It’s clear someone didn’t do their job correctly, and it was probably the electrical design engineer or systems engineer for the pack. I've designed numerous packs and not 1 has gone up in flames. To say that CoCO2 was to blame is nonsense. I could easily design a pack with that chemistry that is safe to the level inherent to the cell itself. Conversely, without proper protection, no cell is truly safe, not even LiFePO4.
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