Intermediate layers for electrode fabrication

Abstract

Provided are novel electrodes for use in lithium ion batteries. An electrode includes one or more intermediate layers positioned between a substrate and an electrochemically active material. Intermediate layers may be made from chromium, titanium, tantalum, tungsten, nickel, molybdenum, lithium, as well as other materials and their combinations. An intermediate layer may protect the substrate, help to redistribute catalyst during deposition of the electrochemically active material, improve adhesion between the active material and substrate, and other purposes. In certain embodiments, an active material includes one or more high capacity active materials, such as silicon, tin, and germanium. These materials tend to swell during cycling and may loose mechanical and / or electrical connection to the substrate.; A flexible intermediate layer may compensate for swelling and provide a robust adhesion interface. Provided also are novel methods of fabricating electrodes containing one or more intermediate layers.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of US Provisional Application No. 61 / 260,297, filed November 11, 2009, entitled "Intermediate Layers for Electrode Fabrication," which is hereby incorporated by reference in its entirety for all purposes. Background technique [0003] High capacity rechargeable batteries are highly desired. Many application areas, such as aerospace, medical devices, portable electronics, and automotive, require high-mass ratio and / or volume-specific capacity batteries. Lithium-ion battery technology represents a significant improvement in this regard. However, to date, the application of this technology has been mainly limited to graphite electrodes, which have a theoretical capacity of only about 372 mAh / g during lithiation. [0004] Silicon, germanium, tin and many other materials are attractive active materials because of their high electrochemical capacity. For example, the theoretical capacity ...

AI Technical Summary

Problems solved by technology

Most polymer binders are not elastic enough to accommodate the expansion of the active material, which leads to the separation between the polymer and the active material particles and the loss of the electrical connection between the active material particles and the current collector during discharge.

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