JCESR supplements its traditional project management approach with scientific “Sprints.” The sprint described in this video involved a multidisciplinary team from Argonne, the University of Illinois at Urbana-Champaign, Massachusetts Institute of Technology, and the University of Michigan. As they studied how polymers in solution can react electrochemically to store energy, the team solved a crucial battery problem: “crossover,” which is caused by molecules mixing together when they should not, resulting in reduced performance.