Microscopic Dendrites Focus in Boeing Dreamliner Probe - Wall Street Journal-Feb 11 2013

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"Microscopic 'Dendrites' a Focus in Boeing Dreamliner Probe", Wall Street Journal news story by Jon Ostrower and Andy Pasztor, quoting directly from their article, "Aviation safety investigators are examining whether the formation of microscopic structures known as dendrites inside the Boeing Co 787's lithium-ion batteries played a role in twin incidents that prompted the fleet to be grounded nearly a month ago.

The new information from the National Transportation Safety Board offers a glimpse into what could become an important line of inquiry for the investigation into a Jan. 7 battery fire aboard a Japan Airlines Co. 787 Dreamliner parked in Boston."

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  • Dear Readers: I must note that from what I have seen and heard from other people (and experienced battery experts in particular) there is a substantial subset (perhaps the majority?) of battery thermal runaways that aren't caused by some sort of external mechanical abuse or external shorting events that are most likely caused by some type of failure in the behavior of a battery pack’s control electronics. No argument with the experts on that point. That said, I am also told by long-experienced battery experts that there is an irreducible, albeit much smaller subset of thermal runaways which were clearly not caused by any sort of external physical or electrical abuse and in which, by any reasonable measure, the control electronics were apparently functioning within spec and were not detecting any anomalies in monitored parameters when a thermal event occurred. This subset is where an LENR ‘nano-fireball’ mechanism could potentially be operating and serve as a proximate cause for runaway events. At the moment, I cannot cite any anomalous post-event forensic isotopic data on runaways which would indicate non-chemical processes at work. However, most if not all runaway investigations have employed EDAX or the equivalent, not SIMS, so at the moment the question is still open. I certainly wish more incident investigators would be on the lookout for telltales of non-chemical processes as possible culprits, but if a runway were in fact caused by just one 100 micron LENR ‘fireball’ at 4,000 to 6,000 Kelvin it might be nearly impossible to locate and measure the minuscule amount of transmuted material left amongst the relatively vast macroscopic mass of debris in a ruined battery cell. That is admittedly a daunting experimental problem. What I can say with great confidence based on voluminous published experimental data concerning LENRs as well as our own theoretical work, is that conditions and reactants that would be very favorable for triggering LENRs in rare instances are absolutely, definitely present on nanometer to micron-sized nanostructures (which include dendrites) inside batteries during the course of microscopic or macroscopic internal electrical shorts. One might reasonably ask, given that LENRs would be rare occurrence at best, why worry at all that they might be happening inside batteries? In my view, depending heavily on their location inside a battery, the answer is that LENRs could serve as an extraordinarily hot ‘match’ with local temperatures that are high enough to potentially be capable of directly initiating even more exothermic metal-oxidation reactions that burn much hotter than a flammable electrolyte fire. Unfortunately, such ‘thermite-like’, pyrotechnic chemical reactions with metals can be nearly impossible to extinguish because they can generate their own Oxygen via dissociation as an advancing flame-front combusts battery materials present inside a casing. In my opinion, that’s where the safety danger lies with regard to LENR-triggered thermal runaways. LENRs may well be a rare, “Black Swan” battery event, but it’s a rather deadly one. Hence, on-board battery systems installed on human-passenger-carrying vehicles such as aircraft and submersibles should ideally be designed with mitigation of this newly recognized type of safety risk in mind.
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Microscopic Dendrites Focus in Boeing Dreamliner Probe - Wall Street Journal-Feb 11 2013

  1. 1. Source = http://online.wsj.com/article/SB10001424127887324880504578298673566960476.htmlMicroscopic Dendrites a Focus in Boeing Dreamliner ProbeASIA BUSINESSUpdated February 11, 2013, 10:45 p.m. ETBy JON OSTROW ER and ANDY PASZTORAviation safety investigators are examining whether the formation of microscopic structuresknown as dendrites inside the Boeing Co 787s lithium-ion batteries played a role in twinincidents that prompted the fleet to be grounded nearly a month ago.The new information from the National Transportation Safety Board offers a glimpse into whatcould become an important line of inquiry for the investigation into a Jan. 7 battery fire aboarda Japan Airlines Co. 787 Dreamliner parked in Boston.Investigators have so far said they know that fire was triggered by short circuits, but haventbeen able to determine the original cause of the incident, or of another one in which anoverheating battery forced an All Nippon Airways Co. 787 in Japan to make an emergencylanding. Japanese investigators have said the battery in that ANA incident also experiencedan internal short-circuit and a "thermal runaway."Dendrites are tiny deposits of lithium resembling microscopic whiskers that can grow withinthe cells of a battery, potentially causing short circuits and significant heat and even fire. Theyare often a byproduct of rapid or uneven charging of lithium-ion batteries, according toexperts.Top NTSB spokeswoman Kelly Nantel said investigators are "looking at whether dendritesmay have been a factor in the short-circuits" that led to the Jan. 7 battery fire.She stopped short of saying investigators have concluded that the structures were theprimary cause of the sequence of events that led to the Japan Airlines lithium-ion batteryrupturing and burning. But her comment suggests that safety board experts are now delvinginto the issue as a major element of their overall probe.Last Thursday, NTSB Chairman Deborah Hersman spelled out the results of the malfunctionsinside the battery aboard the Japan Airlines Dreamliner. She said a number of short-circuitsinside one of eight cells touched off a thermal chain reaction that destroyed the battery anddamaged nearby parts of the plane.At the time, Ms. Hersman also said investigators were casting a wide net looking for thecause of the short-circuits, including how individual cells were charged, the physicalseparation of the cells and their electrical interconnections. Dendrites were not explicitlymentioned.Chemical engineers, scientists and lithium-ion battery-designers have long studied andwritten about the negative impact of dendrites, particularly on the efficiency and safety ofThe Wall Street Journal Copyright 2013 All rights reserved
  2. 2. batteries designed for electric vehicles, and have documented potential hazards includingsudden short-circuits resulting in uncontrollable overheating of batteries."It takes time for the dendrites to grow and [the plane] can have several flights, andeverythings going fine and suddenly" theres a fire, said Professor John Goodenough of theUniversity of Texas at Austin, who is widely credited with the invention of the lithium-ionbattery."The critical factor is charging too fast on some cells," because "only one cell has to gowrong" to create a problem, said Mr. Goodenough, who is still teaching at age 90.Battery experts have enjoyed limited success in identifying clear-cut solutions to control thegrowth of dendrites. Some technical papers have suggested using different electrolytes orchanging the chemical composition of other internal parts to impede the growth of themicroscopic tentacles. The safety board is receiving technical assistance from battery expertsat the Navy and the Department of Energy who, among other issues, have studied the spreadof dendrites.But if Boeing ends up embracing any such solution, it could take extensive laboratory andflight tests to persuade regulators to approve the new battery design.A Boeing spokesman declined to comment, citing restrictions on its ability to discusselements of the NTSBs investigation.The 787 is the first passenger jet to rely heavily on lithium-ion batteries. Boeing 787 chiefengineer Mike Sinnett said last month the company chose lithium-ion "because it has theright chemistry" to discharge a large amount of power to start the auxiliary power unit in thetail of the jet or even its engines "and then allow us to recharge that battery in a relativelyshort period of time."Mr. Sinnett, who said Boeing had never seen a failure of any of the lightweight lithium-ionpower sources in operational testing before the twin incidents in January, described themultiple layers of "robust" protections built into the batterys design, including four layers ofprotection to prevent overcharging or overly rapid discharging.But the NTSB has called into question the certification of the batteries, specifically asking whyproblems that originated inside a single cell resulted in a cascade of cell failures across theunit, after being approved under the condition that such failures couldnt happen.It isnt clear how much of the 787s battery testing concentrated on problems stemming fromthe spread of dendrites. But starting five years ago, government researchers at the NationalRenewable Energy Laboratory in Colorado were focused on variables that influenced suchgrowth inside rechargeable automobile batteries, including charge rates, operatingtemperatures and other factors. Around the same time, various companies were conductingseparate research to develop computer models and other tools to predict how short-circuitscould grow within a cell, potentially sparking thermal runaways.Write to Jon Ostrower at jon.ostrower@wsj.com and Andy Pasztor atandy.pasztor@wsj.comThe Wall Street Journal Copyright 2013 All rights reserved
  3. 3. Lattice Energy LLCRe: comment on appended Feb. 11, 2013, Wall Street Journal story by Ostrower & PasztorDear Readers:I must note that from what I have seen and heard from other people (and experienced batteryexperts in particular) there is a substantial subset (perhaps the majority?) of battery thermalrunaways that aren’t caused by some sort of external mechanical abuse or external shortingevents that are most likely caused by some type of failure in the behavior of a battery pack’scontrol electronics. No argument with the experts on that point.That said, I am also told by long-experienced battery experts that there is an irreducible, albeitmuch smaller subset of thermal runaways which were clearly not caused by any sort of externalphysical or electrical abuse and in which, by any reasonable measure, the control electronics wereapparently functioning within spec and were not detecting any anomalies in monitored parameterswhen a thermal event occurred. This subset is where an LENR ‘nano-fireball’ mechanism couldpotentially be operating and serve as a proximate cause for runaway events. At the moment, Icannot cite any anomalous post-event forensic isotopic data on runaways which would indicatenon-chemical processes at work. However, most if not all runaway investigations have employedEDAX or the equivalent, not SIMS, so the evidentiary question is still an open one needing data.I certainly wish more incident investigators would be on the lookout for telltales of non-chemicalprocesses as possible culprits, but if a runaway were in fact caused by just one 100 micron LENR‘fireball’ at 4,000 to 6,000 Kelvin it might be nearly impossible to locate and measure the minusculeamount of transmuted material left amongst the relatively vast macroscopic mass of debris in aruined battery cell. That is admittedly a daunting experimental problem.What I can say with great confidence based on voluminous published experimental dataconcerning LENRs as well as our own theoretical work, is that conditions and reactants that wouldbe very favorable for triggering LENRs in rare instances are absolutely, definitely present onnanometer to micron-sized nanostructures (which include dendrites) inside batteries during thecourse of microscopic or macroscopic internal electrical shorts.One might reasonably ask, given that LENRs would most likely be rare occurrence at best, whyworry at all about the possibility that they might be happening inside advanced batteries?In my view, depending heavily on their exact location inside a battery and composition of nearbymaterials, the answer is that LENRs could serve as an extraordinarily hot ‘match’ with localtemperatures that are high enough to potentially be capable of directly initiating even moreexothermic metal-oxidation reactions that burn much hotter than a flammable electrolyte fire.Unfortunately, such ‘thermite-like’, pyrotechnic chemical reactions with metals can be nearlyimpossible to extinguish because they can generate their own Oxygen via dissociation as anadvancing flame-front combusts battery materials present inside a casing. In my opinion, that’swhere the safety danger lies with regard to possible LENR-triggered thermal runaways.LENRs may well be a rare, “Black Swan” battery event, but it’s a rather deadly one. Hence, on-board battery systems installed on human-passenger-carrying vehicles such as aircraft andsubmersibles should ideally be designed with mitigation of this newly recognized type of safety riskin mind.Lewis LarsenFebruary 11, 2013Lattice Energy LLC Copyright 2013 All rights reserved
  4. 4. Lattice Energy LLCAddendum:For further details, please see a 28-pp Lattice MS-Word document dated Jan. 23, 2013, regardingLENRs, field failures, and thermal runaway fire/explosion events in Lithium-based batteries:http://www.slideshare.net/lewisglarsen/lattice-energy-llc-field-failures-and-lenrs-in-lithiumbased-batteriesjan-23-2013Summary:Low energy nuclear reactions (LENRs) can potentially provide another physically plausiblemechanism for producing so-called “field failures” that can trigger catastrophic thermal runawayfires and sometimes chemical explosions in Lithium-based batteries.Background on field failures in Lithium-based batteries:There is a heretofore little-appreciated subset of Lithium-based battery problems cryptically calleda “field failure” mode that, while much rarer than ‘plain vanilla’ safety issues such as puncturesand other types mechanical damage or other electrical issues such as over-charging/-discharging,etc., seems to be highly correlated with catastrophic thermal runaway events. According to a majorLithium-ion battery manufacturer in a private communication, field failures apparently occur almostrandomly in roughly 1 out of every 4 to 5 million Lithium-based battery cells right off the productionline, regardless of their chemistry. This statistic has implications for battery safety that have beenunder-appreciated in the past.This somewhat obscure field failure problem involves catastrophic thermal failure of a singlebattery cell. While it is often thought to be associated with internal shorts and electrical arcingwithin a somehow defective cell, some battery manufacturers will admit privately that this peculiarfailure mode is not well-characterized and very poorly understood --- most of them are presently ata loss for ideas about exactly how to definitively mitigate such a problem. It is well known that if justa single cell in a large, multi-cell battery pack fails in this particular manner, it can potentially triggeran even more catastrophic large-scale thermal runaway event that rapidly propagates through anentire battery pack, destroying adjacent cells via thermal fratricide as well as possibly the entireinterior of, for example, an all-electric motor vehicle.LENRs may be involved in presently indeterminate subset of Lithium-based battery failures:This additional new source of concern about the safety of advanced Lithium-based batteries hasarisen because, in the course of our company’s ongoing R&D efforts, Lattice has applied theWidom-Larsen theory of Low Energy Nuclear Reactions (LENRs) on a practical level to try to helpbetter understand the possible role of nanoscale metal dendrites and nanoparticles in certain typesof rare failure modes that may occur in smaller Lithium-based batteries as well as in extremelylarge, multi-thousand-cell battery packs utilized in certain all-electric vehicles and some militaryapplications.Technical questions are welcome.Lewis LarsenFebruary 11, 20131-312-861-0115lewisglarsen@gmail.comLattice Energy LLC Copyright 2013 All rights reserved

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