Silicon has been regarded as one of the most promising anode materials for next-generation, high energy Li-ion batteries. In this talk, we will discuss our recent progresses on the development of high-performance Si anode using two approaches: 1. Development of micron-sized Si with a porous Si nanostructure by impregnating petroleum pitch inside of porous Si to improve its cycle life; and 2. Development of localized, high-concentration electrolytes that can largely extent both cycle life and calendar life of Si based Li-ion batteries. The combination of these two methods can accelerate the application of Li-ion batteries for large-scale electrical vehicles and stationary energy storage applications.