Superionic composite electrolytes with continuously perpendicular-aligned pathways for pressure-less all-solid-state lithium batteries | JoVE Visualize

Area of Science:

Materials Science
Electrochemistry
Solid-state Batteries

Background:

Solid electrolytes are crucial for developing safe, high-energy density battery systems.
Composite solid electrolytes offer potential for high ionic conductivity and stable interfaces, but face challenges in balancing ionic and mechanical properties.
A fundamental trade-off often exists between ion conduction efficiency and mechanical robustness in solid electrolytes.

Purpose of the Study:

To design a composite solid electrolyte that decouples ion conduction from mechanical flexibility.
To achieve high ionic conductivity and maintain mechanical contact with electrodes for improved battery performance.
To demonstrate a versatile composite architecture for advanced battery applications.

Main Methods:

Fabrication of a composite solid electrolyte with alternating layers of perpendicularly aligned (PA) Li$_{0.3}$Cd$_{0.85}$PS$_{3}$ nanosheets and Li-containing polyethylene oxide (PEO) layers.
Characterization of ionic conductivity and mechanical properties of the PA-Li$_{0.3}$Cd$_{0.85}$PS$_{3}$/PEO composite.
Testing of Li||LiNi$_{0.8}$Co$_{0.1}$Mn$_{0.1}$O$_{2}$ coin cells and Li||LiFePO$_{4}$ pouch cells using the developed composite electrolyte.

Main Results:

Achieved a high ionic conductivity of 10.2 mS cm^-1 at 25 °C.
Demonstrated excellent cycling stability in Li||LiNi$_{0.8}$Co$_{0.1}$Mn$_{0.1}$O$_{2}$ coin cells, retaining 92% capacity after 600 cycles.
Successfully facilitated pressure-less operation in Li||LiFePO$_{4}$ pouch cells.
Validated the design by creating a PA-Li$_{0.46}$Mn$_{0.77}$PS$_{3}$/PEO electrolyte with 6.1 mS cm^-1 ionic conductivity and good flexibility.

Conclusions:

The proposed composite solid electrolyte design successfully decouples ionic conduction from mechanical flexibility.
This architecture enables high ionic conductivity and stable electrode interfaces, crucial for advanced battery performance.
The strategy offers a promising pathway for developing safer, high-performance solid-state batteries.