See the way those smooth, amorphous blobs rapidly transform into textured honeycombs? Something similar is probably happening right now inside your laptop or smartphone’s battery, providing you with portable power.

But the cherished efficiency and portability of those compact lithium-ion batteries comes with a cost: each cycle of discharge/recharge degrades the material’s essential structure and ultimate longevity – you’ve probably noticed that your older electronics just don’t hold a charge like they used to. Preventing this persistent degradation requires insight into a process that plays out on the elusive scale of just billionths of a meter.

Fortunately, Brookhaven scientists just demonstrated a breakthrough transmission electron microscopy technique that captures live action lithium-ion reactions with nanoscale precision.

“We’ve opened a fundamentally new window into this popular technology,” said physicist and lead author Feng Wang. “The live, nanoscale imaging may help pave the way for developing longer-lasting, higher-capacity lithium-ion batteries. That means better consumer electronics, and the potential for large-scale, emission-free energy storage.”

These real-time experimental observations, including the movie above, revealed that the lithium ions swept rapidly across the surface of iron fluoride nanoparticles in a matter of seconds. The transformation then moved slowly through the bulk in a layer-by-layer process that split the compounds into distinct regions (similar to spinodal decomposition).

Imagine watching a fire spread across the surface of a log and then steadily eating its way through the layers of wood—only rather than smoke, the lithium ion reaction forms trails of new molecules. Just as burnt wood reveals fundamental characteristics of fire, the changes in morphology and structure in these individual nanoparticles provided crucial information about the lithium reaction mechanisms.

Get the full story at the official press release.

Comments

  1. #1 James Fenton III
    Keno, oregon
    November 28, 2012

    I would be interested if these are being Discharged, and if so, Have they taken images, of the battery, being Charged?
    I wonder if the material,stays in this form or reverts to it’s original shape?
    I have noticed a loss of available Power, in the battery’s that are used in Model Aircraft. The lower available power, was thought to result from the vibration, and shocks that these battery’s are subjected to. It would be real nice to have these battery’s last longer.

    • #2 Justin Eure
      November 30, 2012

      Thanks for your interest! Feng Wang, a study coauthor, was able to respond:
      No, we have not been able to reverse the reaction, and we are working on that. But we learned from our ex-situ TEM studies (not published) that the materials do not return to their original shapes, but instead become much more disordered and smaller in size.

  2. #3 Charlie Scuilla
    DC Area
    November 29, 2012

    We are looking at a depth of discharge reaction at Room Temperature and 100% DoD. correct?

    • #4 Justin Eure
      November 30, 2012

      Thanks for the question! Feng Wang resonded: Yes, actually we recorded the details with videos at a frequency of 2 frames/second, from the pristine to the 100% DOD.