Safe High Rate and Ultra High Capacity with Minimum 4.0 Amp. hour 18650 lithium ion rechargeable cell

In the Phase I SBIR program we developed a 4Ah 18650-size cell (280 Wh/kg) using novel nano Si materials and high capacity positive electrodes. The developed 4A h 18650 cell has great performance characteristics: at -30oC the cell delivers>3 Ah, the cell passes the most challenging UL tests including impact, 130oC hot and crush test, and passes a 2A/20V overcharge test. Significant progress in the cell cycle life has been made after optimizing the high capacity positive electrode design and the selection of a new separator. These findings indicate the direction to further improvements in cell cycle life. The Phase I work that demonstrated feasibility of our 4 Ah 18650-size cell, both in performance and abuse tolerance, serves as a foundation for the Phase II work.