| Description |
Lithium-ion batteries are commonplace in consumer devices, but the volatility of the liquid electrolyte used in those batteries poses an innate safety risk that must be combated if the batteries are to maintain their preferential status in modern technology. One alternative to liquid electrolytes is solid polymer electrolytes that are safe, mechanically and electrochemically stable, and flexible. The current inhibiting factor to the integration of solid polymer electrolytes into lithium-ion batteries is reduced ionic conductivity, but this can be addressed by engineering specific polymer architectures, including single-ion conductors that incorporate the anion into the polymer backbone, that enhance lithium dissociation from the anion and improve its transport. The proposed new comb-branched architectures were modeled using computer simulations to gain an understanding of the atomic-scale processes that inhibit or advance lithium conduction through the polymer network. Conventional solid polymer electrolytes, where both lithium and anion are mobile, were compared with the single-ion conductor electrolytes. In the electrolytes with both ions mobile, the best-performing system was a comb-branched polymer with the longest-simulated tether of 5 carbon-carbon bonds. The single-ion conductors showed that the tethering of the anion to the backbone did not substantially affect ionic conductivity, and transference number for the lithium ion (fraction of conductivity due to lithium) approaches unity. Additional simulations are necessary to ensure that it continues its optimistic performance at lower temperatures. |
