On the Origin and Implications of Li2O2 Toroid Formation in Nonaqueous Li-O2 Batteries
Abstract
The lithium-air (Li-O2) battery has received enormous attention as a possible alternative to current state-of-the-art rechargeable Li-ion batteries given their high theoretical specific energy. However, the maximum discharge capacity in nonaqueous Li-O2 batteries is limited to a small fraction of its theoretical value due to the insulating nature of lithium peroxide, Li2O2, the battery's primary discharge product. In this work, we show that the inclusion of trace amounts of electrolyte additives, such as H2O, significantly improve the capacity of the Li-O2 battery. These additives trigger a solution-based growth mechanism due to their solvating properties, thereby circumventing the Li2O2 conductivity limitation. Experimental observations and a growth model imply that this solution mechanism is responsible for Li2 toroid formation. We present a general formalism describing an additive's tendency to trigger the solution process, providing a rational design route for electrolytes that afford larger Li-air battery capacities.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.