A novel technology for high-performance Lithium‐ion batteries (LIBs), that would enable an electric vehicle (EV) to travel longer distances on a single charge, has been developed.
A research team, jointly led by Professor Nam‐Soon Cho and Professor Sang Kyu Kwak in the School of Energy and Chemical Engineering at UNIST has developed an electrolyte system for high‐energy‐density LIBs via the addition of cyclic aminosilane‐based additives. These additives suppress the formation of surface impurities that damage the electrode protective coating, while at the same time create a protective layer on the anode surface. Besides, with the presence of only 0.5% electrolyte additives, this breakthrough technology can not only improve battery performance, but also protect both the cathode and anode.
Figure 1. a) Schematic illustration of the hydrolysis of LiPF6 to generate acidic compounds in the electrolyte and reactive species (HF and PF5)‐derived problems in batteries. b) HF and H2O scavenging mechanisms of TMS‐ON.
Lithium-ion batteries (LIBs) are rechargeable batteries, in which lithium ions move back and forth between the electrodes (cathode/anode) during charging and discharging. At this time, the passage through which lithium ions pass is the ‘electrolyte’, and the electrolyte itself reacts on the surface of the electrodes (cathode/anode) to form a protective film. Therefore, if the electrodes are changed for high-energy-density LIBs, so as the electrolyte system changes. Ni-rich cathodes have recently attracted considerable attention as a promising candidate for high-energy density LIBs. Since this material is highly reactive, it can easily decompose the existing electrolytes on electrode surface. Besides, lithium hexafluorophosphate (LiPF6), which is commonly utilized as a salt in electrolytes for LIBs, react with trace water to produce acidic compounds. These compounds destroy the electrode protective films, and this lowers battery performance by removing transition metal ions in the electrolytes.