Lithium-Ion Capacitor Electrolyte Additives for High-Temperature Stability

The patent modifies the chemical composition parameters of the nonaqueous electrolytic solution by adding specific additives (compounds with formulas (1) and (2)) to change the electrolyte's properties. This enables the formation of stable solid electrolyte interface films that prevent decomposition reactions, thereby maintaining high energy density while improving high-temperature durability by suppressing gas generation and electrode deterioration.

The patent introduces intermediary substances (additives compounds (1) and (2)) into the electrolytic solution that act as mediators between the electrodes and the electrolyte. These additives preferentially react to form protective interface films on the electrode surfaces, preventing direct harmful interactions between the high-energy-density electrode materials and the electrolyte, thus improving reliability without sacrificing energy density.

The patent changes the electrolytic solution composition by incorporating specific additives that modify the freezing point and viscosity parameters of the electrolyte. These compositional changes prevent lithium dendrite precipitation at low temperatures by altering the ion transport characteristics and preventing solvent crystallization, thereby maintaining both performance and safety across a wide temperature range.

The patent applies beforehand cushioning by pre-forming stable solid electrolyte interface films using the additive compounds before lithium dendrites can form. These pre-formed protective films act as cushioning barriers that prevent lithium ion aggregation and dendrite growth during low-temperature operation, ensuring safety without compromising performance.

The patent modifies the electrolytic solution composition parameters by adding specific compounds that change the electrical conductivity and stability parameters of the electrolyte. This enables high power delivery while maintaining durability by forming stable interface films that prevent degradation during high-rate charging and discharging cycles, thereby improving both output characteristics and cycle stability.

The patent introduces intermediary additive compounds that act as mediators during high-power operation. These additives preferentially adsorb on electrode surfaces and form protective layers that facilitate rapid ion transport (improving power) while simultaneously preventing harmful side reactions and electrode material degradation (maintaining durability and storage characteristics).