Nanotek Instruments, Inc. SBIR Phase I Award, December 2017

This proposal seeks to advance the next generation of portable energy storage by exploiting the high specific energy intrinsic to the Li-S system. While sulfurs low electrical conductivity and the inhibiting effects of polysulfide dissolution have historically impeded the commercialization of Li-S batteries, we propose to overcome these limitations via the utilization of graphene as a multifunctional component. Our approach leverages this 2D nanomaterial to act as (i) an electrically conductive agent, (ii) a polysulfide trap to circumvent active material loss, (iii) a robust framework to buffer volume expansion during cycling, and (iv) a wrapping agent to build uniform and spherical particles for better electrode casting. Because polysulfide dissolution is a multifaceted problem affecting the entire cell, we shall also investigate a graphene-protected anode and non-flammable electrolyte to improve cycle life performance and overall battery safety.By completion of Phase I, we intend to demonstrate a low cost (< $10/kg), high areal density (> 10 mg/cm2) cathode exhibiting improved cycle life and capacity retention bolstered by our graphene-protected anode and electrolyte formulation. In consideration of these outcomes, and our intent co-develop this technology with several industrial customers, we truly believe DoDs advanced energy goals can be realized through our approach.