Controlled synthesis of KCu7S4/rGO nanocomposites for electrochemical energy storage
Controlled synthesis of KCu7S4/rGO nanocomposites for electrochemical energy storage
复制标题
用于电化学储能的 KCu7S4/rGO 纳米复合材料的控制合成
DOI：
10.1016/j.matdes.2020.108992
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发表时间：
2020
影响因子：
8.4
通讯作者：
Dai Shuge
中科院分区：
文献类型：
--
作者：
Shen Weixia;Zang Jinhao;Hu Hao;Xu Junmin;Zhang Zhuangfei;Yan Ruiqiang;Dai Shuge
水性可充电电池具有能量密度大、成本低、安全性高等特点，适用于大规模储能系统。然而，高容量、高循环寿命的负极材料的缺乏仍然阻碍了它的发展。在这里，我们报道了一种新型的隧道结构的KCu7S4水基二次电池负极材料。用X-射线光电子能谱和X射线衍射仪成功地研究了KCu7S4的结构演化和电荷储存机理。电荷储存可以归因于Cu2+深度氧化为Cu2+/Cu3+和良好的可逆反应。电化学诱导的Cu7S4向Cu1.96S的不可逆相变是KCu7S4电极容量退化的主要原因。幸运的是，优化后的KCu7S4/rGO复合电极具有良好的电化学性能，制备的全电池具有良好的储能能力。这些发现可以拓宽负极材料的视野，并为制造先进的充电电池提供新的机会。
Aqueous rechargeable batteries present desired properties of considerable energy density, low-cost and high safety for large-scale energy storage systems. However, the scarcity of available negative electrode materials with high capacity and satisfying cycling life still hinders their development. Here, we report a novel tunnel structured KCu7S4negative electrode material for aqueous rechargeable batteries. The structural evolution and charge storage mechanism of the KCu7S4is successfully studied by usingex-situXPS and XRD. The charge storage can be attributed to the deep oxidation of Cu+into Cu2+/Cu3+and the good reversible reaction. The electrochemical induced irreversible phase transformation of Cu7S4into Cu1.96S is mainly responsible for the capacity degradation of the KCu7S4electrode. Fortunately, the optimized KCu7S4/rGO composite electrode shows good electrochemical performance and the fabricated full cell delivers good energy storage capability. These findings can broaden the horizon of negative elctrode materials and endow new opportunities for the fabrication of advanced rechargeable batteries.