Dr. Sun Hui from the New Energy Research Institute of China University of Petroleum (Beijing) pointed out that the future development of lithium-ion battery electrolytes needs to focus on solving the following issues:
Firstly, there's the safety of the electrolyte and the battery. This can be addressed by using ionic liquids, fluorocarbonates, adding overcharge additives, flame retardants, and employing highly stable lithium salts.
Secondly, increase the operating voltage of the electrolyte. This can be achieved by purifying the solvent, using ionic liquids, fluorocarbonates, or adding additives to the positive electrode surface film.
Third, the operating temperature range needs to be broadened. Low-temperature electrolyte systems require the use of ethers and nitriles with lower melting points; high-temperature systems require the use of ionic liquids (molten salts), new lithium salts, and fluorinated ester ethers to improve the temperature.
Fourth, extending battery life requires precise control of the composition and structure of the solid electrolyte interphase (SEI) membrane, mainly achieved through SEI membrane-forming additives and free transition metal ion scavengers.
Fifth, reduce costs. It is necessary to reduce the cost of lithium salts and solvents, and to solve the technical problem of how to improve battery performance when the purity of lithium salts and solvents is low. This aspect still requires in-depth research.
