STTR Phase I: Carbon-encapsulated sulfur cathodes for next generation batteries

Evoseer Llc, Laramie WY

Investigators

Abstract

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) Phase I project is to enable next-generation lithium battery technologies that are integral in transitioning toward increased renewable energy deployment. In particular, the project has the potential to overcome obstacles to widespread electric vehicle (EV) adoption including battery capacity limitations, high battery cost, and supply chain issues. EVs currently account for a significant majority of the lithium battery market and this market share will likely increase dramatically as deployment of EVs increases in coming years. The aforementioned issues with lithium battery technologies must be addressed for EVs to reach their envisioned potential. This STTR project seeks to advance a novel process for the production of a critical battery component – the battery cathode. This STTR Phase I project proposes to advance lithium sulfide (Li-S) battery viability using a novel approach to cathode production. Lithium sulfide batteries can provide more than double the gravimetric energy density of current lithium batteries, but Li-S batteries suffer from a short cycle life due to the poor retention of polysulfide species which are formed at the cathode during cycling. If these polysulfide species are able to diffuse away from the cathode, they participate in several detrimental reactions and interactions with both the electrolyte and anode, and the battery is damaged. This project seeks to retain the sulfur and polysulfides within the cathode using encapsulation within a carbon scaffold. Specific research will include assessments of the maximum sulfur loading that can be achieved in the carbon scaffold, the extent to which the carbon scaffold can be rendered electrically conductive, construction of cathodes from the sulfur-loaded carbon scaffold, and tests of the performance of batteries constructed from these cathodes. In addition, a technoeconomic analysis of the cathode technology will be performed to assess its potential in the context of current lithium battery technology. Expected outcomes include demonstrated technical and economic viability of the cathode technology. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.