High-Voltage Phosphate Cathodes for Rechargeable Ca-Ion Batteries
High-Voltage Phosphate Cathodes for Rechargeable Ca-Ion Batteries
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DOI：
10.1021/acsenergylett.0c01663
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发表时间：
2020-10-09
影响因子：
22
通讯作者：
Vaughey, John T.
中科院分区：
文献类型：
--
作者：
Kim, Sanghyeon;Yin, Liang;Vaughey, John T.
钙离子电池（CIB）作为下一代储能设备正在接受研究，因为它们理论上具有较高的工作潜力，并且与钙的高天然丰度相关的较低成本。然而，由于缺乏可用的正极材料，CIB的发展受到限制。在这里，我们首次报道了两种功能性聚阴离子磷酸盐材料作为室温下 CIB 的高压阴极。 NaV2(PO4)(3)电极在3.2 V（相对于Ca2+/Ca）附近可逆嵌入0.6 mol Ca2+（81 mA h g(-1)），在3.5 mA g(-1)电流密度下具有稳定的循环性能。在第一次循环中，橄榄石骨架材料FePO4在7.5 mA g(-1)的电流密度下，在2.9 V附近(vs Ca-2(+)/Ca)可逆地嵌入0.2 mol Ca2+ (72 mA h g(-1))。结构、电子和成分的变化与这两种材料中 Ca2+ 的可逆嵌入一致。
Calcium-ion batteries (CIBs) are under investigation as next-generation energy storage devices due to their theoretically high operating potentials and lower costs tied to the high natural abundance of calcium. However, the development of CIBs has been limited by the lack of available positive electrode materials. Here, for the first time, we report two functional polyanionic phosphate materials as high-voltage cathodes for CIBs at room temperature. NaV2(PO4)(3) electrodes were found to reversibly intercalate 0.6 mol of Ca2+ (81 mA h g(-1)) near 3.2 V (vs Ca2+/Ca) with stable cycling performance at a current density of 3.5 mA g(-1). The olivine framework material FePO4 reversibly intercalates 0.2 mol of Ca2+ (72 mA h g(-1)) near 2.9 V (vs Ca-2(+)/Ca) at a current density of 7.5 mA g(-1) in the first cycle. Structural, electronic, and compositional changes are consistent with reversible Ca2+ intercalation into these two materials.