4. Modelli di intertestualità e tipologie di trasformazione

Enabling High Lithium Conductivity in Polymerized Ionic Liquid Block Copolymer Electrolytes

“…[1,[23][24][25][26] Polystyrene or poly(methyl methacrylate) blocks are commonly used for mechanical reinforcement or as dielectric materials, while ethylene oxide-based blocks (PEO) are most frequently used as the ion-conducting block. [1,[23][24][25][26] However, the transport properties of the lithium ion in ethylene oxide-based polymers is dictated by the segmental motions (a relaxations) of the ethylene oxide chains in the amorphous phase, which corresponds to the diffusion of conformational state along the polymer backbone chains, [27] resulting in limited ionic conductivity at temperatures below the melting point of PEO (65 8C). [1,[28][29][30][31] Additionally, lithium ions are coordinated strongly with the coordination sites by oxygen ligands of the ethylene oxide repeat units, thereby hindering lithium ion interchain migration processes, [32,33] thus resulting in a relatively small fraction of charge being carried by the lithium ion (lithium transport number, t Li þ = 0.1-0.2).…”