A Graphene-like Oxygenated Carbon Nitride Material for Improved Cycle-Life Lithium/Sulfur Batteries

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• 作者：Jinghai Liu ; Wanfei Li ; Limei Duan ; Xin Li ; Lei Ji ; Zhibin Geng ; Keke Huang ; Luhua Lu ; Lisha Zhou ; Zongrui Liu ; Wei Chen ; Liwei Liu ; Shouhua Feng ; Yuegang Zhang
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：August 12, 2015
• 年：2015
• 卷：15
• 期：8
• 页码：5137-5142
• 全文大小：463K
• ISSN：1530-6992

文摘

Novel sulfur (S) anchoring materials and the corresponding mechanisms for suppressing capacity fading are urgently needed to advance the performance of Li/S batteries. Here, we designed and synthesized a graphene-like oxygenated carbon nitride (OCN) host material that contains tens of micrometer scaled two-dimensional (2D) rippled sheets, micromesopores, and oxygen heteroatoms. N content can reach as high as 20.49 wt %. A sustainable approach of one-step self-supporting solid-state pyrolysis (OSSP) was developed for the low-cost and large-scale production of OCN. The urea in solid sources not only provides self-supporting atmospheres but also produces graphitic carbon nitride (g-C₃N₄) working as 2D layered templates. The S/OCN cathode can deliver a high specific capacity of 1407.6 mA h g^鈥? at C/20 rate with 84% S utilization and retain improved reversible capacity during long-term cycles at high current density. The increasing micropores, graphitic N, ether, and carboxylic O at the large sized OCN sheet favor S utilization and trapping for polysulfides.