Negative active material for rechargeable lithium battery and rechargeable lithium battery

摘要

A negative active material for a rechargeable lithium battery and a rechargeable lithium battery including the same. The active material includes a silicon-containing compound represented by the following Chemical Formula 1 where Si exists with a concentration gradient from the surface to the center of the negative active material:
SiCx  [Chemical Formula 1]where 1, 0.05≦x≦1.5.

主权项

1. A negative active material layer comprising a negative active material for a rechargeable lithium battery, the negative active material comprising:
a silicon-containing compound of Formula 1:
SiCx  [Formula 1]wherein 0.05≦x≦1.5; wherein the negative active material being particulate in form and comprising a plurality of particles, and wherein carbon and silicon have a relationship of a concentration ratio satisfying the Equation 1:
A>B  [Equation 1]where A is a mole concentration ratio of carbon relative to silicon in a center of each particle; andB is a mole concentration ratio of carbon relative to silicon on surface area of each particle; andthe silicon having a concentration gradient from the surface area to the center of the negative active material, wherein the concentration gradient exists from the surface area of each particle to the center of each particle, wherein each particle has a spherical shape, wherein A is 0.92 and corresponds to the center of each particle, and B is 0.25 and corresponds to the surface area of each particle.