BACKGROUND

Technical Field

The present invention generally relates to batteries and, more particularly, to the use of a thin carbon cathode in lithium-oxygen batteries.

Description of the Related Art

Lithium-ion batteries are prevalent in fields such as consumer electronics, automobiles, medical devices, and home energy storage. In a lithium ion insertion reaction, the number of lithium ions that can be inserted into a host cathode determines the amount of energy stored in the battery. As a result, a large cathode is needed to increase the storage capacity of the battery. There is therefore a limit to how small an effective lithium ion battery can be made while providing a useful energy density.

Lithium-oxygen battery chemistries have a higher gravimetric and volumetric energy density (e.g., about 3,213 Wh/kg and about 7,422 Wh/L respectively with respect to only cathode mass or volume) than one of the most commonly used cathode materials, LiCoO2(e.g., about 1,095 Wh/kg and about 5,543 Wh/L respectively with respect to only cathode mass or volume). Lithium-oxygen batteries therefore present a path toward further miniaturization, decreasing the weight and volume of batteries without sacrificing energy capacity. However, existing lithium-oxygen battery implementations use large, porous cathodes that still impose a volumetric disadvantage for miniaturized applications.

SUMMARY

A method of forming a battery includes forming a thin graphene cathode on a substrate. A lithium anode is formed and an electrolyte is formed between the thin graphene cathode and the lithium anode.

Another method of forming a battery includes forming a cathode on a substrate from a single- or double-layer graphene material and forming a lithium anode. An electrolyte having a high solubility for lithium ions and oxygen between the cathode and the lithium anode is formed, such that lithium ions migrate from the anode through the electrolyte to form Li2O2at a surface of the cathode. The method also includes positioning a current collector formed from a metal mesh in the electrolyte.

These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.

