Carbon microspheres built of La2O3 quantum dots-implanted nanorods: Superb hosts with ultra-long Li2Sn-catalysis durability

Practical utilization of Li-sulfur batteries (LSBs) is still hindered by the sulfur cathode side due to its infe-rior electrical conductivity, huge volume expansion and adverse polysulfide shuttling effects. Though using polar catalysts coupled with mesoporous carbons may well surmount these barriers, such unshel-tered catalysts rarely survive due to oversaturated polysulfide adsorption and extra sulfuration side reac-tions. To overcome above constrains, we herein propose to implant highly reactive nanocatalysts into carbon matrix with few nanometers insertion depth for mechanical protection. As a paradigm study, we have embedded La2O3-quantum dots (QDs) into carbon nanorods, which are then assembled into car-bon microspheres (CMs). As evaluated, La2O3 QDs-CMs can help elevate the cathode redox reaction kinet-ics and sulfur utilization ratios, delivering a large capacity of 1392 mAh g-1 at 0.25C and high-capacity retention of 76% after total cycling. The thin carbon layers on La2O3 QDs exert a key role in impeding excess polysulfide accumulation on catalysts and thus prevent their deactivation/failure. Our strategy may guide a smart way to make catalysts-involved sulfur cathode systems with ultra-long working dura-bility for LSBs applications.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

To address the limitations of the sulfur cathode in Li-sulfur batteries, researchers propose a method of implanting highly reactive nanocatalysts into a carbon matrix for mechanical protection. As a case study, La2O3 quantum dots are embedded into carbon nanorods and assembled into carbon microspheres. The La2O3 QDs-CMs can improve the redox reaction kinetics and sulfur utilization of the cathode, resulting in high capacity and stability. This research provides guidance for developing Li-sulfur battery systems with long working durability.