High Energy-Density and Long Life-time Lithium-Sulfur Batteries Topic and Subtopic: 14a

Conventional lithium-ion batteries demonstrate great potential for applications in electrical vehicles, but they face some major challenges such as low energy density and high cost. It is worthwhile to pursue alternative strategies to address the barriers of cost and energy density. We propose to develop advanced rechargeable lithium-sulfur (Li-S) batteries that have much higher theoretical energy density and lower cost. We will improve the practicality and cycle life of Li-S batteries to make them more commercially viable. In the Phase I project, we will improve the energy density and cycle life of Li-S batteries via two approaches. First, highly conductive lithium-ion exchange membranes will be used as battery separators. Second, concentrated Li electrolytes will be used in electrodes. These efforts will prevent cathode sulfur loss due to the polysulfide shuttle mechanism, thus significantly enhancing the cycle life of Li-S batteries. The proposed lithium-sulfur technology will address two major barriers of electrical vehicles, cost and energy density; therefore it may directly facilitate the deployment and commercialization of electrical vehicles. They may also be applicable in the consumer market to portable electronics and communication devices.