Perpendicularly aligned TiC-coated carbon cloth cathode for high-performance Li-O2 batteries

Abstract

To overcome the theoretical energy density limit of current lithium-ion batteries (LIBs), lithium-oxygen (Li-O-2) batteries based on electrochemical formation and decomposition of lithium peroxide (Li-O-2) have received much attention. However, critical cathode-related issues such as carbon decomposition, irreversible accumulation of Li-O-2, and subsequent cathode passivation severely restrict the performance of Li-O-2 batteries. To manage these issues, this paper reports a perpendicularly aligned TiC-coated carbon cloth (TiC-cloth) for Li-O-2 battery cathodes prepared by a facile carbothermal method using easily available T-shirts as a substrate and growth of TiC on the outer surface. Coating with perpendicularly aligned TiC protects the carbon surface and increases the surface area to accommodate Li-O-2. After verification of the successful coating, electrochemical tests of Li-O-2 batteries were conducted, and the results were compared against TiC nanoparticle electrode casted manually onto carbonized T-shirts. The TiC-cloth affords enhanced oxygen reduction/evolution activity and cyclability for Li-O-2 batteries compared with the TiC nanoparticles. Analyses demonstrate that this improvement arises from the reversible formation and decomposition of Li-O-2 grown along the shape of the TiC on the carbonized T-shirts without carbon decomposition. The study reported here will be a keystone for the intelligent design of stable and efficient cathodes for Li-O-2 batteries.