The energy generation and storage for modern-day sensor networks, communications, and electronics presents a variety of unique challenges. To achieve the long-duration missions away from Earth as outlined in the Vision for Human Exploration in Space, these energy storage systems will need to undergo a dramatic increase in their specific energy densities. Recently, Mainstream has made startling advances in the area of high energy-density batteries using carbon nanotube (CNT) electrodes. However, theory suggests that silicon actually possesses an intercalation capacity that is an order of magnitude above that of carbon. If this is able to be translated into added capacity, it would truly revolutionize Li-ion electrochemistry and energy-storage technologies in general. The Universities Space Research Association has recently developed a process of growing silicon nanorods and has agreed to team with Mainstream for this Phase I STTR effort. This Phase I focuses on developing and testing electrodes comprised of both silicon and carbon nanostructures in Li-ion batteries. Because the basic battery chemistry will not be affected, safety will not be compromised.