Few-Layered Tin Sulfide Nanosheets Supported on Reduced Graphene Oxide as a High-Performance Anode for Potassium-Ion Batteries
Few-Layered Tin Sulfide Nanosheets Supported on Reduced Graphene Oxide as a High-Performance Anode for Potassium-Ion Batteries
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还原氧化石墨烯支撑的少层硫化锡纳米片作为钾离子电池的高性能阳极
DOI：
10.1002/smll.201804806
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发表时间：
2019-03-08
期刊：
影响因子：
13.3
通讯作者：
Xia, Hui
中科院分区：
文献类型：
--
作者：
Fang, Lingzhe;Xu, Jing;Xia, Hui
涉及转化和合金化反应机制的阳极由于其较高的理论容量而成为钾离子电池（PIBs）的研究热点。然而，在钾化/脱钾过程中，严重的体积变化和金属聚集往往导致电化学性能不佳。本文制备了基于还原氧化石墨烯（SnS2@rGO）的多层SnS2纳米片作为PIBs的负极材料，具有高比容量（0.05 A g（-1）时为448 mAh g(-1)）、高倍率（1 A g（-1）时为247 mAh g(-1)）和提高的循环性能（300次循环后容量保持率为73%）。在这种复合电极中，SnS2纳米片在钾化/脱钾过程中经历了顺序转化（SnS2到Sn）和合金化（Sn到K4Sn23， KSn）反应，从而产生了高比容量。同时，由于快速的电子/离子传输、表面电容主导的电荷存储机制以及对体积变化的有效调节，杂化超薄纳米片具有快速的K存储动力学和优异的结构完整性。本研究表明，通过精细结构工程可以显著提高合金和转化基阳极的储钾性能。
Anodes involving conversion and alloying reaction mechanisms are attractive for potassium-ion batteries (PIBs) due to their high theoretical capacities. However, serious volume change and metal aggregation upon potassiation/depotassiation usually cause poor electrochemical performance. Herein, few-layered SnS2 nanosheets supported on reduced graphene oxide (SnS2@rGO) are fabricated and investigated as anode material for PIBs, showing high specific capacity (448 mAh g(-1) at 0.05 A g(-1)), high rate capability (247 mAh g(-1) at 1 A g(-1)), and improved cycle performance (73% capacity retention after 300 cycles). In this composite electrode, SnS2 nanosheets undergo sequential conversion (SnS2 to Sn) and alloying (Sn to K4Sn23, KSn) reactions during potassiation/depotassiation, giving rise to a high specific capacity. Meanwhile, the hybrid ultrathin nanosheets enable fast K storage kinetics and excellent structure integrity because of fast electron/ionic transportation, surface capacitive-dominated charge storage mechanism, and effective accommodation for volume variation. This work demonstrates that K storage performance of alloy and conversion-based anodes can be remarkably promoted by subtle structure engineering.