Lithium salt:

Lithium hexafluorophosphate (LiPF₆) : It has good solubility in organic solvents, can ensure that lithium ions are fully dissociated, achieve high efficiency ion conduction, has high ionic conductivity, can improve the battery charging and discharging efficiency and overall performance, is the most widely used lithium salt in the current commercial lithium battery electrolyte, but it is extremely sensitive to water and high temperature, and will decompose and produce hydrofluoric acid and other corrosive substances.

Lithium difluorosulfonimide (LiFSI) : With excellent ionic conductivity, it can maintain good performance in a wide temperature range, especially the high temperature stability is better than lithium hexafluorophosphate, the moisture tolerance is relatively strong, and the compatibility with positive and negative materials is also excellent, and the effect is remarkable in improving the high temperature performance and cycle life of the battery, and the application of high-performance lithium battery electrolyte is gradually increasing.

Lithium tetrafluoroborate (LiBF₄) : It has good thermal and electrochemical stability and improves battery safety to some extent. However, its relatively low ionic conductivity and solubility in organic solvents is not as good as lithium hexafluorophosphate. This limits its use alone in some battery systems where charge and discharge performance is required.

Organic solvent:

Vinyl carbonate (EC) : It has a high dielectric constant and can dissolve lithium salt well, which is one of the key components of forming a stable electrolytic liquid system. It can participate in forming a stable solid electrolyte interface film (SEI film) on the electrode surface, which has an important impact on the first charge and discharge efficiency and cycle performance of the battery. However, the melting point is high and the viscosity is large at low temperature, which is not conducive to the charge and discharge performance of the battery at low temperature.

Propylene Carbonate (PC) : Has a good solubility, can dissolve lithium salt to ensure the ionic conductivity of the electrolyte, but in the use of graphite anode lithium-ion batteries, it is easy to co-embed on the surface of the graphite anode, destroy the layer structure of graphite, resulting in a sharp decline in battery performance, but in some special battery systems or with other solvents, can also play a role