Si has been regarded as the most promising anode material for next generation high energy Li-ion batteries. Among the tremendous effort made towards the practical application of Si anodes, the design of advanced nanostructures and the development of novel electrolyte systems are crucial in accommodating the Si volume change and enabling a stable solid electrolyte interphase. Recently, our group has made significant progress in these two aspects. In this talk, we will discuss the use of mesoporous Si sponges and hierarchical structured Si/CNT/C microspheres as high performance Si anode materials and the development of localized high concentration electrolyte for commercial nano-Si and graphite composite anodes. The discussion will be focused on high loading electrodes of ~3 mAh/cm² and full cells towards practical applications.