Study Shows How to Stop Lithium Dendrite Formation in Batteries

When they charge, lithium ion batteries form so-called “dendrites” that limit recharging speed. They can also destroy a battery by internal short circuit. Researchers have now found a solution that impedes their formation.

Instead of being charged in hours, electric car batteries could be juiced up in minutes and could last more years than current ones. Until now, experiments that wanted to deal with the issue of dendrites have been conducted empirically, but a team at Purdue University found out how to design such experiments so that they’re able to predict the dendrite formation in their early stages.

The project led by David Ely and R. Edwin García has been funded by Toyota Motor Engineering & Manufacturing North America.

“We believe that this work is the first of its kind because, prior to its publication, work on this area had heavily relied on anecdotal evidence,” said García, an associate professor of materials engineering at Purdue. “While we have applied this theory to lithium-ion batteries, it was formulated so that it could be readily applied to other emerging battery chemistries, such as magnesium-ion and lithium-sulfur.”

They found three approaches that stop the formation of dendrites:

1. Induce lithium deposits to grow uniformly, instead of heterogeneously, which means that instead of growing in spikes, unevenly in various locations on the electrode, lithium should be evenly distributed uniformly, allowing for the battery to be charged faster, using high voltages.

2. Modifying the anode chemistry to prevent the creation of dendrites.  This means inhibiting lithium’s beading at the surface and having it only wet the anode.

3. Charging in rapid pulses instead of a constant current.

“We have developed an analytical theory that identifies the different ways in which lithium-ion batteries can fail during recharge,” García said. “Fundamentally, we proposed a universal roadmap that allows experimentalists and theoreticians to explore the different regimes of behavior during battery recharging. The proposed analytical roadmap enables researchers to identify the charging conditions that will completely suppress or at least minimize the formation of lithium dendrites.”

Their study found a method of keeping the dendrites from growing beyond their “critical kinetic radius,” which is the size at which they will either shrink or continue to grow, depending on how much current is applied to them.

Learning how lithium ion batteries work will let scientists understand how to make them more resistant to cold weather (such in the case with Tesla’s recent NYT scandal), charge faster and be cheaper and more environmentally-friendly. It means that in a few years will may have cars that go for 500 miles on a charge and juicing them up wouldn’t take much more than fueling a gas car.