Silicon-containing alloys useful as electrodes for lithium-ion batteries

Abstract

An electrode composition for a lithium ion battery has the formula SixSnqMyCz, where q, x, y, and z represent atomic percent values and (a) (q + x) > 2y + z; (b) q >= 0, (c) z >= 0; and (d) M is one or more metals selected from manganese, molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, or a combination thereof. The Si, Sn, M, and C elements are arranged in the form of a multi-phase microstructure comprising: (a) an amorphous phase comprising silicon; (b) a nanocrystalline phase comprising a metal suicide; and (c) a phase comprising silicon carbide phase when z > 0; and (d) an amorphous phase comprising Sn when q > 0.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to US Application 60 / 743,075, filed December 23, 2005, the disclosure of which is incorporated herein by reference in its entirety. technical field [0003] The present invention relates to electrode compositions suitable for use in lithium ion batteries, methods of preparing such compositions and batteries comprising such compositions. Background technique [0004] Metal alloys have been proposed as anodes for lithium-ion batteries. These alloy-type anodes generally exhibit higher capacities relative to intercalation-type anodes such as graphite. One problem with such alloys, however, is that they often exhibit relatively poor cycle life and poor Coulombic efficiency due to fragmentation of alloy particles during expansion and contraction associated with compositional changes in the alloy. Contents of the invention [0005] Described herein is an electrode composition for lithium-...

AI Technical Summary

Problems solved by technology

However, a problem with such alloys is that they often exhibit relatively poor cycle life and poor Coulombic efficienc...