Compared With The Conventional Electrolyte, The High-concentration Lithium Salt Electrolyte Is Unusual

The electrolyte is the carrier of ion transmission, which has an important influence on the current density, cycle stability and safety of lithium batteries. Due to the solvation effect, the high-concentration lithium salt electrolyte has many special additional properties compared to conventional electrolytes. Its application in lithium batteries can promote the further application and development of lithium batteries.

First of all, the most prominent performance of the high-concentration electrolyte is high-pressure resistance, flame retardancy, and can effectively improve the safety of the battery. Secondly, the anions in high concentration electrolyte are easy to be reduced to become the main component of SEI membrane, which makes SEI membrane more stable. High concentration electrolyte can also effectively inhibit the oxidation and decomposition of electrolyte at high potential, reduce the volatility of solvent and improve the coulomb efficiency. In addition, the high-concentration electrolyte not only inhibits the corrosion of aluminum foil without LiPF6, but also inhibits the dissolution and migration of polysulfides, reduces the effect of the shuttle effect on battery performance, and improves the cycle stability of lithium-sulfur batteries.

Everything has two sides. Although the high-concentration electrolyte has excellent performance, there are also differences on the other side. For example, high-concentration electrolytes have higher viscosities, poorer wettability to interfaces such as electrodes, and special solvated structures will reduce lithium ion migration activity and affect electrical conductivity.

According to published reports, by adding a wetting agent to reduce the viscosity of the high-concentration electrolyte, improve the problem of poor electrolyte wettability, and make the high-concentration electrolyte fully exhibit excellent performance.

In general, the study of high-concentration electrolytes is of great significance for the development of high-energy density and high-security lithium-ion batteries.