Negative Electrodes Improve Safety in Lithium Cells and Batteries

Conventional lithium-ion battery configurations often contain graphite electrodes, which operate at a potential very close to that of metallic lithium and are extremely reactive. This composition can cause lithium-ion batteries to overheat, particularly if the battery is in a charged state or if it is overcharged without protective electronic circuitry. Argonne scientists have developed a new class of intermetallic materials  that can be effectively used as a negative electrode (anode) for non-aqueous lithium electrochemical cells and batteries that offer significantly higher volumetric and gravimetric capacity when compared to graphite.

The structure of these new intermetallic electrodes is represented by the formula M₂M', in which M and M' consist of two or more metal elements, including silicon, and have a Cu₂Sb- type structure. The M’ atoms have a configuration that is close to an ideal face-centered-cubic array of atoms and provide a host framework for the M atoms in the parent structure and for lithium atoms during the electrochemical reaction. With this innovation, Argonne researchers have enabled a new type of anode that enhances the stability and safety of rechargeable lithium-ion batteries.

• Significant increase in energy density
• Improves safety
• Increases reliability
• Greater structural stability
• Superior charge capacity

• Transportation applications, such as electric and hybrid-electric vehicles
• Portable electronic devices, such as cell phones and laptop computers
• Medical devices
• Space, aeronautical, and defense-related devices