Ammonium Fluoride Mediated Synthesis of Anhydrous Metal Fluoride–Mesoporous Carbon Nanocomposites for High-Performance Lithium Ion Battery Cathodes
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- 作者：Jinyoung Chun ; Changshin Jo ; Sunhye Sahgong ; Min Gyu Kim ; Eunho Lim ; Dong Hyeon Kim ; Jongkook Hwang ; Eunae Kang ; Keun Ah Ryu ; Yoon Seok Jung ; Youngsik Kim ; Jinwoo Lee
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2016
- 出版时间：December 28, 2016
- 年：2016
- 卷：8
- 期：51
- 页码：35180-35190
- 全文大小：852K
- ISSN：1944-8252
文摘
Metal fluorides (MF<sub>xsub>) are one of the most attractive cathode candidates for Li ion batteries (LIBs) due to their high conversion potentials with large capacities. However, only a limited number of synthetic methods, generally involving highly toxic or inaccessible reagents, currently exist, which has made it difficult to produce well-designed nanostructures suitable for cathodes; consequently, harnessing their potential cathodic properties has been a challenge. Herein, we report a new bottom-up synthetic method utilizing ammonium fluoride (NH<sub>4sub>F) for the preparation of anhydrous MF<sub>xsub> (CuF<sub>2sub>, FeF<sub>3sub>, and CoF<sub>2sub>)/mesoporous carbon (MSU–F–C) nanocomposites, whereby a series of metal precursor nanoparticles preconfined in mesoporous carbon were readily converted to anhydrous MF<sub>xsub> through simple heat treatment with NH<sub>4sub>F under solventless conditions. We demonstrate the versatility, lower toxicity, and efficiency of this synthetic method and, using XRD analysis, propose a mechanism for the reaction. All MF<sub>xsub>/MSU–F–C prepared in this study exhibited superior electrochemical performances, through conversion reactions, as the cathode for LIBs. In particular, FeF<sub>3sub>/MSU–F–C maintained a capacity of 650 mAh g<sup>–1sup><sub>FeF3sub> across 50 cycles, which is ∼90% of its initial capacity. We expect that this facile synthesis method will trigger further research into the development of various nanostructured MF<sub>xsub> for use in energy storage and other applications.