Scientist have been studying how to boost the performance of a lithium battery as well as determine why lithium batteries explode.

Dendrites

As a lithium battery is used dendrites form on the surface of the battery's electrode. Dendrites grow like whiskers inside lithium batteries and can cause bad things to happen.

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Dendrites can cause batteries to loose power faster, short out, or even in some cases catch fire.

Researchers at the University of Michigan have been studying the growth of dendrites inside lithium batteries. The researchers are attempting to link voltage patterns to specific dendrite activity with next-gen lithium metal batteries. They have observed how dendrites grow and wither over the course of a battery's cycle. They also observed dendrites breaking off the electrode mid-cycle to become lithium floating around inside the battery.

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The Michigan researchers have developed a see through lithium metal battery (visualization cell) to observe and further study dendrites.

3 minute video by Michigan Engineering published 14 October 2016

Cryo-Electron Microscopy

On 4 October 2017 Jacques Dubochet, Joachim Frank and Richard Henderson won the Chemistry Nobel prize for cryo-electron microscopy. Cryo-electron microscopy was first used by Henderson in 1975 to produce the first 3D model of the protein called bacteriorhodopsin.

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Cryo-electron microscopy has ushered in a resolution revolution for transforming images into 3D structures.

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Cryo-electron microscopy is not only completely transforming structural biology, it also is aiding in the study of dendrites in lithium batteries. Scientist from Standord University and the Department of Energy's SLAC National Accelerator Laboratory had used cryo-electron microscopy to capture the first images of dendrite growth.

Better Lithium Batteries Using Nano-Diamonds

Diamond nanoparticles, nano-diamonds (ND), are currently used in the metal electroplating industry. Researchers have studied the use of nano-diamonds in suppressing the growth of dendrites in lithium batteries.

The following figure shows the properties of electrolyte lithium ion electroplating with and without nano-diamonds (ND).

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a. electroplating bath
b. dendrite growth with and without nano-diamonds (ND)
c. Nano-diamond particles
d. electrolyte with and without nano-diamonds
e. size distribution of nano-diamond agglomerates in the electrolyte
f. illustration of the nano-diamond particle with lithium ions absorbed from the electrolyte

This figure shows the morphology of lithium deposits after electroplating, the left-hand side is without nano-diamonds and the right-hand side is with nano-diamonds.

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Coulombic Efficiency

Coulombic efficiency measures the efficiency with which electrons (charge) is transferred in a system facilitating an electrochemical reactions.

The coulombic efficiency of the nano-diamond electrolyte is 96% in lithium/copper cells compared to 88% for the nano-diamond-free electrolyte.

Promising Future for Long Lasting Lithium Batteries

As more and more research is brought to bare on suppressing dentrite growth and increasing battery performance, the future is looking bright. Just with the techniques already discovered it is possible that exploding lithium batteries will be a thing of the past.