A team of researchers at Tohoku University in Japan has created a new type of lithium ion conductor for future batteries that could be the basis for a new generation of solid-state batteries. These batteries could avoid the flame risks that liquid chemistries involving lithium salts dissolved in organic solvents present.
As reported in Newswise, the new approach uses rock salt lithium borohydride (LiBH4), which until now had been considered for use in battery applications only at high temperatures or pressures.
In the journal APL Materials, from AIP Publishing, the researchers describe how they doped a cubic lattice of potassium iodide (KI) molecules with the LiBH4, allowing them to stabilize the high-pressure form of Lithium borohydride and make a solid solution at normal atmospheric pressure that was stable at room temperature.
Newswise reports that in traditional doping techniques, a small amount of stabilizing element is added to a conductor abundant in lithium. In contrast, Hitoshi Takamura, who led the research at Tohoku University, described the LiBH4 dopant as a parasite operating by a mechanism he and his colleagues call “parasitic conduction.” This mechanism could potentially operate anywhere that small amounts of Li+ ions could be used to dope an oxide, sulfide, halide, or nitride host material.
“This work suggests the potential of this mechanism in the ongoing search for the perfect material for use in solid-state batteries,” said Takamura. “The urgency of this quest has been abundantly clear after the grounding of so many aircraft in recent months.”
Read the research paper “Synthesis of rock-salt type lithium borohydride and its peculiar Li+ ion conduction properties” here.