Structural low-temperature organic polymer batteries

Structural energy and power systems combine the load-bearing capabilities of structural composites with the energy storage capabilities of batteries and supercapacitors. The potential benefit is reduced mass and volume in electrified transportation, enhanced resilience to impact, and improved safety. Desired characteristics include high stiffness, dimensional stability with cycling, high energy, and high power. In addition, batteries in extreme low temperature environments (such is space or polar environs) must maintain operation, but freezing of the electrolyte or reduced electrode kinetics present serious challenges. Current lithium-ion batteries do not meet all these requirements. This talk will focus upon how electrodes and electrolytes themselves can bear enhanced stiffness for structural low temperature batteries. Because ion desolvation at the electrode is a rate limiting step at low temperatures for Li-ion batteries, we implement an alternative battery chemistry that uses conversion rather than intercalation. This chemistry relies on redox-active polymers as the active material for the anode and cathode, and the polymers are integrated into carbon fiber fabrics as structural supports and conductive scaffolds. To complement the organic battery chemistry, a low-temperature bi-continuous structural battery electrolyte (SBE) is developed, consisting of solid epoxy and liquid electrolyte phases. Together, the SBE exhibits a good combination of stiffness and ionic conductivity. The battery, possessing the mechanical properties of a carbon fiber fabric, operates well at temperatures as low as -40 °C.