Solid-State Batteries

Solid-State Batteries

Future solid-state batteries may have higher energy density, better safety and comply form factor than that of current organic electrolyte based Li-ion batteries. However, solid-state electrolytes are difficult to process and have higher interfaces. Polymer composites hold promise for improved processability and interface properties.

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Composite Ion Conductor

Composite Ion Conductor

Improving the mechanical strength for ceramic solid electrolytes, such as lithium phosphorus sulfide families, for pressure-driven dendrite blocking as well as reducing electronic conductivity to prevent a dendrite formation inside the electrolytes is very important to extend the lifespan of all-solid-state lithium metal batteries.

Here, we proposed a low-temperature solution-precipitation process to prepare polymer-solid electrolyte composites for highly uniform polymer distribution in the electrolyte to enhance their mechanical strength and reduce their electronic conduction. The composites up to 12 weight percent of polymer were prepared and exhibited high ionic conductivities up to 0.3 mS/cm.

Furthermore, the electrochemical stability of the electrolyte composites on Li striping/plating cycles was investigated. We confirmed that the proposed solution-precipitation process makes the composite much stabler than the bare solid electrolyte and outperform the similar composites from the other existing preparation methods, such as mechanical mixing and solution-dispersion.

Comparison of three possible methods for preparing the solid electrolyte-polymer composites.
(a) Comparison of three possible methods for preparing the solid electrolyte-polymer composites. Note that the solution-precipitation method has an advantage of a high mechanical strength owing to its smaller polymer-domain size and uniformly distributed microstructure. (b) Schematic showing the preparation process of the solution-precipitation method.