TDA RESEARCH, INC. — Department of Defense SBIR Phase I: N152-093

Description

Batteries with multi-electron redox materials offer promise for increased performance relative to state of the art lithium-ion batteries. Lithium-sulfur (Li-S) batteries have two electron cathode materials (in addition to a lithium metal anode) and better than two times the specific energy of Li-ion batteries.<br><br>However, several issues have prevented Li-S batteries from becoming more commercially viable. The sulfur cathode is both ionically and electronically insulating and so requires a conductive matrix. In addition, cycle life is limited by diffusion of polysulfides to the anode where they are reduced to Li-S2 and become inactive; historically the cycle life has been relatively poor (<50 cycles). A stable and conductive matrix is the key to achieving high capacity and long life in Li-S batteries. <br> <br>TDA will develop ideal cathode compositions by engineering the pore sizes of a highly conductive carbon matrix that contains the polysulfide active materials. We are uniquely qualified to make these nanomaterials because for over ten years we have been developing carbons for ultracapacitors, and through this work we have developed and have patented methods to control the nanopore size distribution. These mesoporous carbons are high purity, highly conductive and inexpensive.