Expected properties of a polymer electrolyte

For battery applications, the specifications for polymer electrolyte are as follows:

• sufficient ionic conductivity at room temperature (σ > 10 ^–2 S/m) to approach the performance of a liquid electrolyte;

• a lithium ion transport number, t ⁺ , close to unity. The majority of polymer electrolytes known to date have a lithium ion transport number < 0.5. This means that at most half the current flowing through the electrolyte is carried by Li ⁺ ions, with the remainder carried by anions. This results in the formation, during battery operation, of a salt concentration gradient in the electrolyte thickness, which has deleterious effects on dendritic growth and severely limits...