From Metal–Organic Framework to Li2S@C–Co–N Nanoporous Architecture: A High-Capacity Cathode for Lithium–Sulfur Batteries

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• 作者：Jiarui He ; Yuanfu Chen ; Weiqiang Lv ; Kechun Wen ; Chen Xu ; Wanli Zhang ; Yanrong Li ; Wu Qin ; Weidong He
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：December 27, 2016
• 年：2016
• 卷：10
• 期：12
• 页码：10981-10987
• 全文大小：497K
• ISSN：1936-086X

文摘

Owing to the high theoretical specific capacity (1166 mAh g^–1), lithium sulfide (Li₂S) has been considered as a promising cathode material for Li–S batteries. However, the polysulfide dissolution and low electronic conductivity of Li₂S limit its further application in next-generation Li–S batteries. In this report, a nanoporous Li₂S@C–Co–N cathode is synthesized by liquid infiltration–evaporation of ultrafine Li₂S nanoparticles into graphitic carbon co-doped with cobalt and nitrogen (C–Co–N) derived from metal–organic frameworks. The obtained Li₂S@C–Co–N architecture remarkably immobilizes Li₂S within the cathode structure through physical and chemical molecular interactions. Owing to the synergistic interactions between C–Co–N and Li₂S nanoparticles, the Li₂S@C–Co–N composite delivers a reversible capacity of 1155.3 (99.1% of theoretical value) at the initial cycle and 929.6 mAh g^–1 after 300 cycles, with nearly 100% Coulombic efficiency and a capacity fading of 0.06% per cycle. It exhibits excellent rate capacities of 950.6, 898.8, and 604.1 mAh g^–1 at 1C, 2C, and 4C, respectively. Such a cathode structure is promising for practical applications in high-performance Li–S batteries.