Scaling While Shorting: Lessons Learned When Non-Unity Coulombic Efficiency Is Independent of Cycle Life

摘要

The modern lithium ion battery has been engineered to impressive standards, with coulomibic efficiency approaching 99.999% and a safety record for well manufactured cells of less that on incident in 10,000,000 cell given the correct environmental and cycling standards. But the ion-shuttle mechanism within the the battery sets up the relationship C_(remaining) = C_(initial) η_c~(cycles) Over the past few years we have redesigned a zinc bromine battery that decouples this relationship almost completely, with the goal of C_(remaining) ≠ C_(initial) η_c~(cycles) In this approach we purposefully trade entropy management for cycle life, but it is not without its cost and challenges. In this presentation I will review the progress and challenges of a battery that does not fail critically under internal short circuit conditions, and discuss pathways and pitfalls we have discovered along the way.