Researchers in Japan say they have identified new solid materials that could lead to the production of “potentially-safer” lithium-ion batteries.
According to a study published in the journal Science and Technology of Advanced Materials, research led by Makoto Moriya, of Shizuoka University’s Department of Chemistry, has identified solid crystals that “self-assemble” to form channels for an electric current that could lead to the manufacture of safer batteries.
Shizuoka University said in a statement accompanying Moriya’s study: “Batteries are made of two oppositely charged electrodes separated by a liquid, gel-like, or solid ‘electrolyte’ medium through which electrically charged atoms, or ions, move. In many cases, these electrolytes are toxic and flammable, so researchers have been looking for non-toxic alternatives.”
Moriya “investigated molecular crystals for this purpose”, the university said. “To obtain the crystals, he added an organic compound to lithium salt. The molecules self-assembled to form channels through which lithium ions moved, creating an electric current. Changing the crystals’ structures affected their ion-conducting functions.”
Ion conductivity in these materials “was not as high as in organic liquids, inorganic ceramics or glass electrolytes”, but it was comparable to polymer electrolytes, “which have been targeted as potential solid electrolytes”, the university said.
In addition, the amount of flammable organic substances in the molecular crystalline electrolytes “was lower than in polymer electrolytes and in conventional liquid electrolytes, making them a potentially-safer alternative”, the university said.
“Moriya found it easy to control the crystal structure of these solid materials by making alterations to their molecules,” the university said. “This structural versatility could prove to be a powerful tool for dramatically improving ion conductivity in these materials.”
Moriya said his observations “could open the door to the design of new solid electrolytes and thus the development of new molecular devices”.
The study— ‘Construction of nanostructures for selective lithium-ion conduction using self-assembled molecular arrays in supramolecular solids’—is online.
