Polymer solid electrolyte membrane and lithium secondary battery containing the same

Polymer solid electrolyte with lithium transport channels secured by nitrogen-doped graphene nanosheet fillers

This technology features a solid electrolyte with nitrogen-doped graphene nanosheets dispersed within a polymer matrix. The lone pair electrons of the nitrogen atoms effectively coordinate lithium ions and create transport channels, enhancing both ionic conductivity and lithium-ion mobility.

Conventional polymer solid electrolytes, such as PEO, suffer from very low room-temperature ionic conductivity, typically around 10^-8 S/cm. Previous research involving filler additives has also struggled to simultaneously achieve both improved ionic conductivity and desired physical properties.

This technology incorporates nitrogen-doped graphene nanosheets containing pyridinic-N and pyrrolic-N at 2–4 wt% of the total electrolyte membrane weight. The lone pair electrons of the doped nitrogen increase affinity for lithium ions, while vacancies created by the removal of oxygen functional groups act as ion transport channels, improving electrochemical performance. Applicable to solid electrolyte layers in wearable devices, flexible display power sources, and medical micro-batteries where leakage must be avoided, it achieves room-temperature operational ionic conductivity with only a small amount of filler.

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Key Features:

• Nitrogen-doped graphene nanosheets dispersed in a polymer matrix, featuring pyridinic-N or pyrrolic-N within the graphene unit layers
• Nitrogen atoms in the nitrogen-doped graphene nanosheets that possess lone pair electrons to coordinate and conduct active cations
• Polymer solid electrolyte membrane containing nitrogen-doped graphene nanosheets in a range of greater than 2 wt% to less than 4 wt% of the total weight
• Process of preparing an electrolyte membrane by applying a slurry of a polymer matrix and nitrogen-doped graphene nanosheets mixed in an organic solvent onto a substrate and drying it

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