Scientists find new way to develop non-flammable, all-solid-state lithium batteries

Seoul: Scientists have discovered a new way to develop all-solid-state lithium batteries that will not be at risk of exploding or burning easily.

The method involves melting the solid electrolyte and coating that melted electrolyte around the electrodes.

The organic liquid electrolyte, mainly used in existing lithium-ion batteries, has a characteristic of easily getting gasified or burned, researchers said.

Therefore, all-solid-sate lithium batteries are now getting an attention as the alternative option since they are non-flammable.

However, the powder type of solid electrolyte does not permeate, compared to the liquid electrolyte. If the contact between electrolytes and electrode active materials is not active, it would be more difficult to move lithium-ion to the electrode.

Furthermore, it will not be simple to elevate the performance revelation of batteries.

To solve these problems, Yoon Seok Jung from Ulsan National Institute of Science and Technology and Seng M Oh from Seoul National University in South Korea developed a way to coat the active materials with the solid electrolyte.

This process called the solution-process works by diffusing the powder type of active material in the liquid from melted solid electrolyte and vaporising the solvent.

After the solution-process, it became more possible to coat the layers of solid electrolyte on the active materials.

The researchers also developed a material for the solid electrolyte by adding the iodised lithium (LiI) to the methanol liquid which is the compound (Li4SnS4) based on tin (Sn).

The compound's ionic conductivity was originally low, but it got increased by getting mixed with LiI.

Consequently, by combining two materials together, it became possible to develop the solid electrolyte with high ion conductivity and air stability.

"A newly developed solid electrolyte has the high ion conductivity and no toxicity problem," Jung said.

"In addition, the prices of a raw material and a solvent (methanol) are comparatively low. With this technology, commercialisation of solid lithium battery will be available sooner than we thought," he said.

The research was published in the journal Advanced Materials.