Improved high capacity rechargeable batteries

Abstract

An electrically active electrode material for use with a lithium ion cell, a lithium ion cell, and a method for forming the electrochemically active material electrode material are described. The electrode material is in the form of a sheet or mat formed of a valve metal material formed of filaments of a valve metal not larger than about 10 microns in cross section, and coated with an electrochemically active material such as silicon nanoparticles.

Description

Background technique [0001] Demand for high-capacity rechargeable batteries is strong and growing every year. Many applications such as aerospace, medical devices, portable electronics, and automotive applications require batteries with high gravimetric and / or volumetric capacity. Lithium-ion electrode technology could provide a major improvement in this regard. However, to date, Li-ion batteries using graphite are limited to a theoretical specific energy density of 372 mAh / g. [0002] Silicon, germanium, tin and many other materials are attractive active materials because of their high electrochemical capacity. For example, silicon has a theoretical capacity of about 4200mAh / g, which corresponds to Li 4 .4Si phase. However, many of these materials are not widely used in commercial lithium-ion batteries. One reason is that some of these materials exhibit significant volume changes during cycling. Silicon, for example, expands by as much as 400 percent when charged to its...

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Problems solved by technology

This in turn produces a substantially more homogeneous capacitor material, resulting in significantly higher values ​​of CV / g

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