title: Robust, Ultra-Tough Flexible Cathodes for High-Energy Li-S Batteries.
abstract: Sulfur cathodes have become appealing for rechargeable batteries because of their high theoretical capacity (1675 mA h g(-1)). However, the conventional cathode configuration borrowed from lithium-ion batteries may not allow the pure sulfur cathode to put its unique materials chemistry to good use. The solid(sulfur)-liquid(polysulfides)-solid(sulfides) phase transitions generate polysulfide intermediates that are soluble in the commonly used organic solvents in Li-S cells. The resulting severe polysulfide diffusion and the irreversible active-material loss have been hampering the development of Li-S batteries for years. The present study presents a robust, ultra-tough, flexible cathode with the active-material fillings encapsulated between two buckypapers (B), designated as buckypaper/sulfur/buckypaper (B/S/B) cathodes, that suppresses the irreversible polysulfide diffusion to the anode and offers excellent electrochemical reversibility with a low capacity fade rate of 0.06% per cycle after 400 cycles. Engineering enhancements demonstrate that the B/S/B cathodes represent a facile approach for the development of high-performance sulfur electrodes with a high areal capacity of 5.1 mA h cm(-2), which increases further to approach 7 mA h cm(-2) on coupling with carbon-coated separators.
authors.affiliation: Electrochemical Energy Laboratory and Materials Science and Engineering Program, The University of Texas at Austin, Austin, TX, 78712, USA.
authors.forename: Sheng-Heng
authors.initials: SH
authors.lastname: Chung
authors.affiliation: Electrochemical Energy Laboratory and Materials Science and Engineering Program, The University of Texas at Austin, Austin, TX, 78712, USA.
authors.forename: Chi-Hao
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Electrochemical Energy Laboratory and Materials Science and Engineering Program, The University of Texas at Austin, Austin, TX, 78712, USA.
authors.forename: Arumugam
authors.initials: A
authors.lastname: Manthiram
keywords: Li-S batteries; battery chemistry; cell configurations; energy storage; porous electrodes