High Energy Organic Cathode for Sodium Rechargeable Batteries
High Energy Organic Cathode for Sodium Rechargeable Batteries
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DOI：
10.1021/acs.chemmater.5b02569
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发表时间：
2015-11-10
影响因子：
8.6
通讯作者：
Kang, Kisuk
中科院分区：
文献类型：
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作者：
Kim, Haegyeom;Kwon, Ji Eon;Kang, Kisuk
在自然系统中，有机电极作为传统无机电极的替代品，在可持续性和普遍可获得性方面受到了极大的关注。然而，低工作电压和低能量密度是阴极应用的固有限制。在这里，我们提出了一种用于钠离子电池的高能有机阴极，它使用了一种苯醌衍生物C6Cl4O2，它是钠电池有机电极中平均电压最高的电极之一(类似于2.72V vs Na/Na+)。它还利用双电子转移来提供580Wh kg(-1)的能量。密度泛函理论(DFT)计算表明，在苯醌结构中引入电负性元素显著增加了钠的存储电位，从而提高了电极的能量密度，后者大大高于已知的醌衍生阴极。通过将C6Cl4O2引入到具有多孔碳模板的纳米复合材料中，提高了C6Cl4O2的循环稳定性。这防止了活性分子溶解到周围的电解液中。
Organic electrodes have attracted significant attention as alternatives to conventional inorganic electrodes in terms of sustainability and universal availability in natural systems. However, low working voltages and low energy densities are inherent limitations in cathode applications. Here, we propose a high-energy organic cathode using a quinone-derivative, C6Cl4O2, for use in sodium-ion batteries, which boasts one of the highest average voltages among organic electrodes in sodium batteries (similar to 2.72 V vs Na/Na+). It also utilizes a two-electron transfer to provide an energy of 580 Wh kg(-1). Density functional theory (DFT) calculations reveal that the introduction of electronegative elements into the quinone structure significantly increased the sodium storage potential and thus enhanced the energy density of the electrode, the latter being substantially higher than previously known quinone-derived cathodes. The cycle stability of C6Cl4O2 was enhanced by incorporating the C6Cl4O2 into a nanocomposite with a porous carbon template. This prevented the dissolution of active molecules into the surrounding electrolyte.