Lithium-ion batteries are widely used in electric vehicles, smartphones and other aspects, in the pursuit of higher performance at the same time manufacturers also attach great importance to battery safety. Recently, Japanese scientists have proposed a new electrolyte component that can improve battery safety at higher voltages.
The study was carried out by a team of scientists at the University of Tokyo (UT) who focused on the electrolyte portion of the battery. The solution carries lithium ions back and forth between the electrodes of the battery when charging and discharging, and delivers a higher performance than most existing lithium batteries by replacing the solvents used in mainstream batteries for safe, highly stable operation and high pressure.
“The voltage of the battery is mainly limited by electrolyte materials, ” says Professor Yamada, a researcher at the University of Tokyo. Electrolyte solvents in current lithium-ion batteries still use solvents that were just commercialized in the early 1990s. So we found ways to improve. Our new fluorinated cyclic phosphate solvent (TFEP) electrolyte significantly improves existing ethyl carbonate (EC). “
It is understood that the team designed its ring-shaped phosphate-based electrolyte by combining the chemical structure of conventional electrolyte solvent EC and flame retardant. This provides phosphate properties for both molecules, including the high-pressure resistance of solvents and non-flammable properties of flame retardants, thus minimizing the risk of lithium batteries catching fire.
In synthesizing electrolytes, the researchers found that the most effective formulations contained 0.95 M LiN (SO2F) 2 in TFEP / 2,2,2-trifluoroethimethyl carbonates. This particular component can synthesize electrolytes with non-combustible properties and zero self-extinguishing time, and enable graphite negative and high-pressure LiNi0.5Mn1.5O4 positive pole to operate steadily.
“Surprisingly, the new electrolyte solvent can increase the battery voltage from the current 3.8 V to 4.6 V, which also extends battery life,” said Professor Yamada. “