Multi- functional nanowall arrays with unrestricted Li plus transport channels and an integrated conductive network for high- areal- capacity Li- S batteries

摘要

The rational design of cathode hosts with superior polysulfide (PS) confinement properties, excellent Li+/e(-) transport and improved cyclability is of the utmost importance for high-areal-capacity lithium-sulfur (Li-S) batteries. Herein, multi-functional nanowall arrays (MNWAs) combining the aforementioned properties are fabricated to improve the electrochemical performance of Li-S batteries with high areal sulfur loadings. The integrated conductive networks and top-down vertically aligned Li+ transport channels are beneficial to Li+/e(-) transport, resulting in high rate performance with a discharge capacity of 620 mA h g(-1) at a high current density of 9.6 mA cm(-2) for 4 mg cm(-2) sulfur-loaded S/MNWA electrodes. Additionally, the strong PS shuttling suppression via the synergetic effects of physical confinement and chemical adsorption leads to Li-S batteries with a sulfur loading of 10 mg cm(-2) capable of delivering a high areal capacity of 12.4 mA h cm(-2) with a high capacity retention of nearly 85% for over 100 cycles. What's more, the Li-S batteries assembled with 4 mg cm(-2) sulfur-loaded S/MNWA electrodes show an ultra-low capacity decay of 0.07% per cycle over 400 cycles at 3.2 mA cm(-2).