A metal-free organic-inorganic aqueous flow battery
A metal-free organic-inorganic aqueous flow battery
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DOI：
10.1038/nature12909
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发表时间：
2014-01-09
期刊：
影响因子：
64.8
通讯作者：
Aziz, Michael J.
中科院分区：
文献类型：
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作者：
Huskinson, Brian;Marshak, Michael P.;Aziz, Michael J.
随着间歇性可再生能源（如太阳能或风能）发电比例的增长，存储大量电能的能力越来越重要。固体电极电池在峰值功率下保持放电的时间太短，无法完全调节风能或太阳能输出（1，2）。相反，液流电池可以通过将所有电活性物质保持在流体形式（3-5）来独立地缩放系统的功率（电极面积）和能量（任意大的存储体积）分量。然而，液流电池的大规模利用受到这些材料的丰度和成本的限制，特别是那些使用氧化还原活性金属和贵金属电催化剂的材料（6，7）。在这里，我们描述了一类能量存储材料，利用了被称为醌类分子家族的有利的化学和电化学性质。我们展示的示例是基于9，10-蒽醌-2，7-二磺酸（AQDS）的氧化还原化学的无金属液流电池。AQDS在硫酸介质中于玻碳电极上发生快速可逆的双电子双质子还原反应。具有廉价碳电极的水液流电池，将醌/氢醌电对与Br-2/Br-氧化还原电对组合，在1.3A cm（-2）下产生超过0.6W cm（-2）的峰值电流功率密度。这种醌溴化物液流电池的循环显示每个循环> 99%的存储容量保持率。有机蒽醌物质可以从廉价的商品化学品合成（8）。这种有机方法允许通过添加官能团来调节重要的性质，例如还原电位和溶解度：例如，我们证明了向AQDS添加两个羟基使电池的开路电位增加11%，并且我们描述了进一步增加电池电压的途径。使用p-芳族氧化还原活性有机分子代替氧化还原活性金属代表了以大大降低的成本实现大规模电能存储的新的和有前途的方向。
As the fraction of electricity generation from intermittent renewable sources-such as solar or wind-grows, the ability to store large amounts of electrical energy is of increasing importance. Solid-electrode batteries maintain discharge at peak power for far too short a time to fully regulate wind or solar power output(1,2). In contrast, flow batteries can independently scale the power (electrode area) and energy (arbitrarily large storage volume) components of the system by maintaining all of the electro-active species in fluid form(3-5). Wide-scale utilization of flow batteries is, however, limited by the abundance and cost of these materials, particularly those using redox-active metals and precious-metal electrocatalysts(6,7). Here we describe a class of energy storage materials that exploits the favourable chemical and electro-chemical properties of a family of molecules known as quinones. The example we demonstrate is ametal-free flow battery based on the redox chemistry of 9,10-anthraquinone-2,7-disulphonic acid (AQDS). AQDS undergoes extremely rapid and reversible two-electron two-proton reduction on a glassy carbon electrode in sulphuric acid. An aqueous flow battery with inexpensive carbon electrodes, combining the quinone/hydroquinone couple with the Br-2/Br- redox couple, yields a peak galvanic power density exceeding 0.6 W cm(-2) at 1.3 A cm(-2). Cycling of this quinone-bromide flow battery showed >99 per cent storage capacity retention per cycle. The organic anthraquinone species can be synthesized from inexpensive commodity chemicals(8). This organic approach permits tuning of important properties such as the reduction potential and solubility by adding functional groups: for example, we demonstrate that the addition of two hydroxy groups to AQDS increases the open circuit potential of the cell by 11% and we describe a pathway for further increases in cell voltage. The use of p-aromatic redox-active organic molecules instead of redox-active metals represents a new and promising direction for realizing massive electrical energy storage at greatly reduced cost.