A novel one‐step reaction sodium‐sulfur battery with high areal sulfur loading on hierarchical porous carbon fiber
Qiubo Guo,
Shuo Sun,
Keun‐il Kim,
Hongshen Zhang,
Xuejun Liu,
Chenglin Yan,
Hui Xia
Affiliations
Qiubo Guo
School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing China
Shuo Sun
School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing China
Keun‐il Kim
Department of Chemistry Oregon State University Oregon Corvallis USA
Hongshen Zhang
School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing China
Xuejun Liu
Key Laboratory of Advanced Carbon Materials and Wearable Energy, Technologies of Jiangsu Province Soochow Institute for Energy and Materials Innovations, College of Energy Soochow University Suzhou China
Chenglin Yan
Key Laboratory of Advanced Carbon Materials and Wearable Energy, Technologies of Jiangsu Province Soochow Institute for Energy and Materials Innovations, College of Energy Soochow University Suzhou China
Hui Xia
School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing China
Abstract Room temperature sodium‐sulfur (RT Na‐S) batteries are gaining extensive attention as attractive alternatives for large‐scale energy storage, due to low cost and high abundancy of sodium and sulfur in nature. However, the dilemmas regarding soluble polysulfides (Na2S n , 4 ≤ n ≤ 8) and the inferior reaction kinetics limit their practical application. To address these issues, we report the activated porous carbon fibers (APCF) with small sulfur molecules (S2 – 4) confined in ultramicropores, to achieve a reversible single‐step reaction in RT Na‐S batteries. The mechanism is investigated by the in situ UV/vis spectroscopy, which demonstrates Na2S is the only product during the whole discharge process. Moreover, the hierarchical carbon structure can enhance areal sulfur loading without sacrificing the capacity due to thorough contact between electrolyte and sulfur electrode. As a consequence, the APCF electrode with 38 wt% sulfur (APCF‐38S) delivers a high initial reversible specific capacity of 1412 mAh g−1 and 10.6 mAh cm−2 (avg. areal sulfur loading: 7.5 mg cm−2) at 0.1 C (1 C = 1675 mA g−1), revealing high degree of sulfur utilization. This study provides a new strategy for the development of high areal capacity RT Na‐S batteries.
