Long‐Life Lithium–Sulfur Batteries with a Bifunctional Cathode Substrate Configured with Boron Carbide Nanowires |
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Authors: | Liu Luo Sheng‐Heng Chung Hooman Yaghoobnejad Asl Arumugam Manthiram |
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Affiliation: | McKetta Department of Chemical Engineering and Texas Materials Institute, The University of Texas at Austin, Austin, TX, USA |
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Abstract: | Developing high‐energy‐density lithium–sulfur (Li–S) batteries relies on the design of electrode substrates that can host a high sulfur loading and still attain high electrochemical utilization. Herein, a new bifunctional cathode substrate configured with boron‐carbide nanowires in situ grown on carbon nanofibers (B4C@CNF) is established through a facile catalyst‐assisted process. The B4C nanowires acting as chemical‐anchoring centers provide strong polysulfide adsorptivity, as validated by experimental data and first‐principle calculations. Meanwhile, the catalytic effect of B4C also accelerates the redox kinetics of polysulfide conversion, contributing to enhanced rate capability. As a result, a remarkable capacity retention of 80% after 500 cycles as well as stable cyclability at 4C rate is accomplished with the cells employing B4C@CNF as a cathode substrate for sulfur. Moreover, the B4C@CNF substrate enables the cathode to achieve both high sulfur content (70 wt%) and sulfur loading (10.3 mg cm?2), delivering a superb areal capacity of 9 mAh cm?2. Additionally, Li–S pouch cells fabricated with the B4C@CNF substrate are able to host a high sulfur mass of 200 mg per cathode and deliver a high discharge capacity of 125 mAh after 50 cycles. |
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Keywords: | boron carbide electrochemical performance first‐principle calculations high‐loading cathodes lithium– sulfur batteries |
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