Monday, March 27, 2017

A battery controversy that I have no expertise to comment upon

Via random clicking on Twitter, this article on Quartz by Steve LeVine about the latest from John Goodenough is very interesting:
Researchers have struggled for decades to safely use powerful—but flammable—lithium metal in a battery. Now John Goodenough, the 94-year-old father of the lithium-ion battery, is claiming a novel solution as a blockbuster advance. 
If it proves out, the invention could allow electric cars to compete with conventional vehicles on sticker price. The improbable solution, described in a new paper from Goodenough and three co-authors, has drawn intense interest from leading science and technology publications. He estimates that the solution could store five to ten times as much energy as current standard lithium-ion batteries. That’s enough to have Google’s Eric Schmidt tweeting about it. 
However, other leading battery researchers are skeptical, even mystified, by Goodenough’s claim. For his invention to work as described, they say, it would probably have to abandon the laws of thermodynamics, which say perpetual motion is not possible. The law has been a fundamental of batteries for more than a century and a half. 
...Hence the excitement over the new paper by Goodenough and his team published in Energy and Environmental Science. A Feb. 28 release from the University of Texas reported they had figured out how to incorporate an electrode—an anode—made of pure lithium or sodium metal, which because of their potential energy has been a top goal for decades. A key is the use of glass as the electrolyte, the substance that connects a battery’s two electrodes and facilitates the shuttling of ions to create electricity.... 
But Goodenough’s battery has pure metallic lithium or sodium on both sides. Therefore, the voltage should be zero, with no energy produced, battery researchers told Quartz.
Goodenough reports energy densities multiple times that of current lithium-ion batteries. Where does the energy come from, if not the electrode reactions? That goes unexplained in the paper.
Here's a long Medium post by Princeton's Dan Steingart, outlining his objections - it's worth a perusal. It will be fascinating to see if anyone can reproduce this.

(From a media criticism perspective, the amount of excitement in the popular press is amusing, especially in contrast with the quizzical nature of the responses in the Quartz article. Also, an open letter to give Goodenough the Nobel Prize, which seems pretty reasonable, current controversy aside.) 

1 comment:

  1. I've worked a little on polymer electrolytes, but not on any inorganics. The devil is always in the details, but on the face of it, it seems pretty doable. Glass has been studied for a while as an inorganic material for battery electrolytes and shown promise. Read the abstract only, since I don't have a subscription.

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