High Performance Anode for Advanced Li Batteries

Over the past fifteen years, the demand for improved battery performance has increasingly focused on the development of battery chemistries based on lithium, due to their advantages over alternate battery chemistries. Among various alternative anodes, one thrust has been the use of materials that form alloys with lithium, providing up to a 10 fold improvement in the energy densities of current anode materials made from graphitic materials. Silicon-coated nanocarbons are among the best performing composite material, providing increases in energy and power densities. The technical performance of silicon-coated carbon nanofibers and nanotubes has been confirmed and well-established by numerous research groups and is potentially transformative for applications dependent on electrochemical energy storage; however, a barrier to utilization of this innovative solution is the high cost of fabrication, and the consequent lack of availability of the material for the battery manufacturing community. The goal of the proposed Phase I SBIR effort is to advance the manufacturing technology for novel, high- performance anodes based on silicon-coated carbon nanofiber, by creating a framework for production and utilization of low-cost silicon-coated carbon nanofibers for the battery industry. The outcomes sought through this developmental effort are increased throughput, energy savings, and consequent cost reductions; coupled with methods of quality control for the silicon-coated carbon nanofiber composite anode material. These two accomplishments will provide the sustainable competitive advantages needed to enable production of the improved anode material at a price reduction from ~ $300/lb to $20/lb or below, competitive to the cost but substantially higher in performance than current anode materials. It is proposed to utilize a fluidized bed reactor for production of silicon-coated carbon nanofiber, to enable both high volume, low-cost production and real-time characterization of the coatings. Commercial Applications and Other Benefits: The proposed manufacturing technology will increase the throughput, reduce the cost and improve the quality of silicon-coated carbon nanofiber composite anode materials. The automotive battery market is identified as a high value, near-term market for this anode technology. In addition to the automotive markets, there is significant interest in the silicon-coated carbon nanofiber technology from military and aerospace organizations. These and other high-volume markets such as consumer electronics warrant continued development of this low-risk, high-reward material. The advancements and solutions that are proposed herein are marked improvements in manufacturing technology for advanced lithium ion anodes that will provide stimulus for domestic production of high capacity lithium ion batteries and battery materials, providing the US with a competitive advantage in manufacturing of the next generation of energy storage devices based on lithium chemistry.