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Title: Understanding batteries on the micro- and nanometer scale

In order to understand performance limitations and failure mechanisms of batteries, one has to investigate processes on the micro- and nanometer scale. A typical failure mechanism in lithium metal batteries is dendritic growth. During discharge, lithium is stripped of the anode surface and migrates to the cathode. During charge, lithium is deposited back on the anode. Repeated cycling can result in stripping and re-deposition that roughens the surface. The roughening of the surface changes the electric field and draws more metal to spikes that are beginning to grow. These can grow with tremendous mechanical force, puncture the separator, and directly connect the anode with the cathode which can create an internal short circuit. This can lead to an uncontrolled discharge reaction, which heats the cell and causes additional exothermic reactions leading to what is called thermal runaway. ORNL has developed a new technology called liquid electron microscopy. In a specially designed sample holder micro-chamber with electron-transparent windows, researchers can hold a liquid and take images of structures and particles at nanometer size. It's the first microscope holder of its kind used to investigate the inside of a battery while cycled.
Publication Date:
OSTI Identifier:
1133025
Resource Type:
Other
Research Org:
ORNL (Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States))
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE BATTERY; BATTERY MECHANICS; BATTERY FAILURE; LIQUID ELECTRON MICROSCOPY; LITHIUM