Indian researchers develop tech to stop dendrites in solid-state lithium batteries

From pv magazine India

Solid-state lithium-ion batteries with lithium anodes offer higher energy densities and are safer than conventional liquid electrolyte-based Li-ion batteries. However, a long-standing challenge with solid-state batteries is the growth of lithium dendrites across the solid-state electrolyte layer, leading to the premature shorting of cells.

Researchers from the Indian Institute of Science, Bangalore, have come up with a new interfacial engineering approach to enable fast charge-discharge rates in solid-state lithium metal batteries. They have found that nanoscopic refractory metal layers like tungsten could improve the performance of these batteries by improving dendrite growth tolerance in solid-state electrolytes. 

The team found that Li-ion currents were concentrated at the edges of the microscopic voids. The currents at these edges were around 10,000 times larger than average currents in the cell. Hence it is necessary to impede void growth to prevent dendrite growth.

To delay void growth, the researchers experimented with an ultra-thin layer of refractory metals between the lithium anode and the solid electrolyte. They noted that tungsten is an ideal candidate to impede lithium vacancy motion due to its low solubility for lithium and therefore delay void growth. They collaborated with researchers from Carnegie Mellon University to corroborate their work through computational methods. 

The team now plans to build on these advances to develop full solid-state cells that could enable charging in less than an hour, while offering up to 1,000 or more cycles at temperatures of 45 C or higher.