Pyridyl Electrolyte Additives for Stable Li-Ion Battery Interfaces

The patent introduces a compound containing a pyridyl group as an intermediary substance in the electrolyte. This compound acts as a mediator that preferentially reacts with electrode materials to form protective interface films, preventing direct harmful interactions between the conventional electrolyte components and the electrode plates. The pyridyl-containing compound sacrifices itself to create a stable interface layer, reducing side reactions and improving cycling performance.

The patent modifies the chemical composition parameters of the electrolyte by incorporating compounds with pyridyl groups (such as pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, or 2,6-dimethylpyridine) at specific concentrations (0.08% to 1% by mass). This parameter change alters the electrochemical behavior at the electrode interfaces, leading to improved stability and reduced side reactions without compromising the basic electrolyte functionality.

The patent employs pyridyl-containing compounds that perform multiple functions simultaneously: they act as interface stabilizers, side reaction inhibitors, and cycling performance enhancers. This multi-functionality allows a single additive class to address multiple performance issues without requiring separate formulations for each function, thereby limiting the increase in device complexity.

The patent creates a composite electrolyte system by combining conventional electrolyte components with pyridyl-containing additives. This composite approach integrates the benefits of established electrolyte formulations with the protective effects of the pyridyl compounds, achieving improved interface stability while maintaining a relatively simple overall formulation structure that builds upon existing technology.