New technology to examine lithium whiskers for safe and durable batts

• A group of scientists from three research universities has grown and observed a lithium dendrite, which will allow preventing the growth of such structures.

Dendrite is a several-hundred-nanometer-thick needle-shaped structure growing from anode toward cathode in a lithium battery. Such projections both shorten battery’s service life and can lead to ignition.

The group of Chinese and American researchers has succeeded in growing a lithium dendrite in an ETEM with the help of CO2. The latter reacts with Li, forming a layer of oxide, which makes dendrites more stable.

The scientists have used a probe of an AFM as an auxiliary electrode. This technology has allowed them to simultaneously image the projection growth and measure the growth stress. 

Very high stress leads to piercing and breaking of solid electrolytes. Thus, dendrite continues growing and causes electrical short circuits. 

Knowing the allowable growth stress will allow creating a proper solid electrolyte. The optimal option is safe and energy-dense solid-state metal batts based on Li.