New Strategy for Manufacturing Fast-Charging Solid-State Batteries

In what’s being called a breakthrough, researchers at the Indian Institute of Science (IISc.) and their collaborators have uncovered how next-generation solid-state batteries fail and devised a new strategy to make those batteries last. longer and charge faster.

Solid-state batteries are set to replace the lithium-ion batteries found in almost all portable electronic devices. But with repeated or excessive use, they grow thin filaments called “dendrites” that can short out batteries and render them unusable.

In a new study published in Nature Materials, researchers have identified the root cause of this dendrite formation – the early appearance of microscopic voids in one of the electrodes. They also show that adding a thin layer of certain metals to the surface of the electrolyte significantly delays the formation of dendrites, extending the life of the battery and allowing it to be charged faster, explained a press release from the IISc.

Vikalp Raj, a PhD student at Naga Phani Aetukuri, assistant professor in the Solid State and Structural Chemistry Unit (SSCU) and corresponding author of the study, artificially induced the formation of dendrites by repeatedly loading hundreds of battery cells, by cutting out thin sections of the lithium-electrolyte interface, and viewing them under a scanning electron microscope. “When they looked closely at these sections, the team realized that something was happening long before the dendrites formed – microscopic voids were developing in the lithium anode during discharge. also calculated that the currents concentrated at the edges of these microscopic voids were about 10,000 times greater than the average currents through the battery cell, which likely created stress on the solid electrolyte and accelerated the formation of dendrites,” says the press release.

The researchers introduced an ultrathin layer of a refractory metal – a metal resistant to heat and wear – between the lithium anode and the solid electrolyte, which protects the solid electrolyte from stress and redistributes the current to some extent, according to the statement cited the researchers. as explaining.

The team collaborated with researchers from Carnegie Mellon University in the US, who performed a computer analysis that clearly showed that the refractory metal layer did indeed retard the growth of microscopic lithium voids.

The researchers say the results are a crucial step in realizing practical, commercial solid-state batteries.

Irene B. Bowles