Energy storage is important for electrification of transportation and for high renewable energy utilization, but there is still considerable debate about how much storage capacity should be developed and on the roles and impact of a large amount of battery storage and a large number of electric vehicles. This paper aims to answer some critical questions for energy storage and electric vehicles, including how much capacity and what kind of technologies should be developed, what are the roles of short-term storage and long-duration storage, what is the relationship between energy storage and electrification of transportation, and what impact will energy storage have on materials manufacturing and supply chain. Accelerating the deployment of electric vehicles and battery production has the potential to provide terawatt-hour scale storage capability for renewable energy to meet the majority of the electricity need in the United States. However, it is critical to greatly increase the cycle life and reduce the cost of the materials and technologies. Long-lasting lithium-ion batteries, next generation high-energy and low-cost lithium batteries are discussed. Many other battery chemistries are also briefly compared, but 100 % renewable utilization requires breakthroughs in both grid operation and technologies for long-duration storage. New concepts like dual use technologies should be developed.