| Institution: | 1. Department State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 China
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore;2. Department State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 China;3. School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore;4. College of Aerospace Engineering, Chongqing University, Chongqing, 400044 China;5. Department of Chemistry, Faculty of Science and Technology, Thammasat University, Pathum Thani, 12120 Thailand;6. School of Materials Science and Engineering, Peking University, Beijing, 100871 China |
| Abstract: | Passivation of the sulfur cathode by insulating lithium sulfide restricts the reversibility and sulfur utilization of Li?S batteries. 3D nucleation of Li2S enabled by radical conversion may significantly boost the redox kinetics. Electrolytes with high donor number (DN) solvents allow for tri-sulfur (S3??) radicals as intermediates, however, the catastrophic reactivity of such solvents with Li anodes pose a great challenge for their practical application. Here, we propose the use of quaternary ammonium salts as electrolyte additives, which can preserve the partial high-DN characteristics that trigger the S3?? radical pathway, and inhibit the growth of Li dendrites. Li?S batteries with tetrapropylammonium bromide (T3Br) electrolyte additive deliver the outstanding cycling stability (700 cycles at 1 C with a low-capacity decay rate of 0.049 % per cycle), and high capacity under a lean electrolyte of 5 μLelectrolyte mgsulfur?1. This work opens a new avenue for the development of electrolyte additives for Li?S batteries. |
