An Alternative Explanation for Boeing’s Lithium-Ion Battery Failures
The phrase “design for manufacturability” takes on new relevance for Boeing as they offered up their latest solution to solve the 787 Dreamliner’s lithium-ion battery woes.
According to the New York Times, the fixes require quite a bit of re-working, in that the proposed Boeing solution now involves a titanium venting system and steel box that would add 150 pounds to the weight of the plane – which may eliminate the weight savings from using the lithium-ion battery in the first place.
That solution comes as a result of what many believe to be the root cause of the battery failures – that too much energy generates too much heat, and the battery lacks an effective cooling mechanism to help dissipate the energy.
In other words, “it’s very possible that [the battery] could heat itself to the point at which it would burst into flames,” said Donald Sadoway, an MIT professor and battery researcher, as quoted in this article.
But what if something else entirely is causing the battery issue?
Norman Chow, president of Kemetco Research, suggests that, “as the largest battery component, the manganese supplied needs to be without metallic impurities, or can potentially contribute to thermal runaway (the overheating of Li-Ion battery materials leading to possible fire or explosion).”
Chow goes on to say that these impurities, at the part-per-billion level, are “known to cause an unacceptable number of batteries to experience thermal run-away in rechargeable Li-Ion batteries.”
We discussed this theory with Larry Reaugh, CEO of junior mining company American Manganese, who explained the issue this way: “The current process used to mine the manganese involves heavy crushing and grinding with heavy steel bodies [ed. note: this is referred to in the industry as grinding media] and big batteries contain 500 to 1,000 cells…the more cells you add, the greater the potential you have to get a particle of metal that could penetrate the membrane and create a short.”
American Manganese has collaborated with Chow at Kemetco to bring to market a different type of process – one involving hydrometallurgical processing.
The conventional EMD (electrolytic manganese dioxide) process involves high-temperature roasting. These high temperatures require lots of energy and tend to work for high-grade manganese only; or, said differently, the economics of this energy-intensive process only work for higher-grade deposits.
The hydrometallurgical process, on the other hand, eliminates the crushing and grinding, which lowers the risk of impurities during the remainder of the processing stages.
In the case of Boeing’s proposed battery fix, according to Donald Sadoway, “the approach seemed to focus more on dealing with battery failure than preventing [it].” Perhaps the aerospace industry can glean something from the automotive sector, which is, on the whole, more advanced in the realm of battery technology.
Do Kemetco Research and American Manganese have a plausible theory on the lithium-ion battery failures? They obviously have a vested interest in putting their theory forward, so what do MetalMiner readers think?
Leave a comment and let us know!
3 Comments
Still, Science remains fascinated with the nano carbon super capacitors? Will they one day power light planes in place of flamable gasoline? Already used in model planes? Perhaps the power behind the Chreos electric car’s 1000 km claims? We are on the threashold of an new and electric propelled world now?
The theory seems very flawed especially for Boeing battery. Boeing battery has Lithium Cobalt Oxide (LCO) chemistry so the impurities in magnese supply has no relevance to Boeing battery fire. In addition, all the tests/investigations carried out on GS Yuasa battery doesn’t show any “red flags”. It is true though that LCO chemistry is inherently less safe. Based on the information available in public domain, there are no obvious week points in the quality control of the cell but it is possible that cells which are safe individually if not put properly in a pack design may endanger battery pack safety.
Currently, lithium batteries are tested for several weeks to try to assure safety, but this still does not eliminate possibilites of thermal runaway, explosions and fires. Stability is the name of the game, whether a company uses cobalt as their cathode, or electrolytic manganese dioxide ( EMD) or chemical manganese dioxide (CMD). American Manganese Inc, can potentially solve this issue that arises with current lithium battery instability. The prototype batteries they have produced contain no impurities and therefore, potentially are the most stable lithium ion batteries in the technology world. The process that is used by American Manganese Inc. to make EMD and CMD uses no grinding of the material mined, as their Mn is available in a soft, friable material that does not require that — no roasting either — the result with their hydrometalllurgical process is a very pure material with no rogue metals in it. Since their EMD and CMD have no contaminants, their lithium manganese spinel batteries they have produced as prototypes are exceptionally stable. This company differs from everyone else that way – other Lithium batteries produced by other companies, suffer from instability. Why would industry build a steel box to contain explosion and fire — at 30,000 feet no less ? Wouldn’t the intelligent answer be to have no explosions at all ?