DNA-Guided Li2S Nanostructure Deposition for High-Sulfur-Loaded Li-S Batteries

초록

The low areal capacity caused by low sulfur loading (<2.0mgcm(-2)) and the poor sulfur utilization due to theinsulating Li2S layer covering the cathode always limitthe practical applications of lithium-sulfur batteries (Li-Sbatteries). Deoxyribonucleic acid (DNA)-controlled nucleation andgrowth of Li2S in the Li-S system were first studiedin this work. The negatively charged sugar-phosphate backbone of DNAcould attract Li+ ions and allow crystalline Li2S to grow along the DNA chains. The electrodeposition of Li2S with a unique three-dimensional nanostructure during the polysulfideconversion and deposition process was realized, which can not onlyboost electron and ion transport but also expose and retain more activesites in the cathode. A Li-S battery with ultrahigh sulfurloading of 10 mg cm(-2) and a low electrolyte/sulfurratio of 6.08 delivered a high areal capacity of 8.1 mA h cm(-2), which is more than 2 times that of commercial Li-ion batteries,demonstrating a great enhancement of the Li-S battery comparedto other studies. Therefore, this study provides an effective strategyof DNA-guided 3D Li2S deposition for achieving high-sulfur-loadingLi-S batteries.

키워드