| abstract |
The present invention relates to a porous silicon based negative electrode active material and a method for preparing the same, the porous silicon based negative electrode active material comprising: a core part including Si and M x Si y ; and a shell part including Si and a number of pores on the core part, wherein M in the above M x Si y is one or more elements selected from the group consisting of elements of 2A group, 3A group and 4A group, and transition metals, and 1≤x≤4 and 1≤y≤4 are satisfied. According to one embodiment of the present invention, capacity characteristics and lifetime characteristics of a lithium secondary battery are improved by minimizing volumetric expansion of the negative electrode active material when being charged or discharged. |