Formation of Li3O4 nano particles in the discharge products of non-aqueous lithium-oxygen batteries leads to lower charge overvoltage.

摘要: Density functional theory calculations are made for bulk thermodynamic properties and surface energies of Li2O2, a primary discharge product, Li3O4, possible byproduct in the products, non-aqueous lithium–oxygen batteries. Results show that standard formation Gibbs free energy Li3O4 is marginally higher than but much lower. Low results both lowered nucleation nanometer regime, allowing nano particles to nucleate ahead Li2O2 during process exist stably when particle sizes smaller about 40 nm. The scanning transmission electron microscopy (STEM) image crystals simulated compared with measured STEM product particles. consistency between images suggests phase can as product. profile oxygen evolution reaction (OER) occurring on most abundant surfaces also calculated. predicted overpotential OER {0001} (0.30 V) shows good agreement experimental data. presence more electronically conductive tends decrease charge overvoltage batteries, explaining why lower voltage area (<3.5 was widely observed charging An increase pressure or temperature enhances stability proportion consequently leading overall overvoltage.