Triphasic Electrolytes for Membrane-Free High-Voltage Redox Flow Battery
Triphasic Electrolytes for Membrane-Free High-Voltage Redox Flow Battery
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DOI：
10.1021/acsenergylett.3c02594
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发表时间：
2023-12
影响因子：
22
通讯作者：
Rajeev K. Gautam;Xiao Wang;Soumalya Sinha;Jianbing Jimmy Jiang
中科院分区：
文献类型：
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作者：
Rajeev K. Gautam;Xiao Wang;Soumalya Sinha;Jianbing Jimmy Jiang
无隔膜液/液两相电池是一种很有前途的氧化还原液流电池。然而，这种电池固有地在液/液界面处经历自放电，导致低库仑效率和差的容量保持。在此，我们报道了一种包含全非水电解质的三相系统，以克服两相系统中的挑战。通过引入第三电解质层以分离阳极电解液和阴极电解液，该系统有效地阻止了自放电事件，而不损害库仑效率和容量保持率。采用金属锂作阳极，吩噻嗪衍生物C18-PTZ（0.5M）作阴极。此外，我们设计了两个全非水三相模型，无论是垂直堆叠的相或物理分离的两相侧向沿着与一个共同的界面层在顶部。有趣的是，这两种设计在静态（98%，31天，100次循环）和流动（99%，39天，100次循环）条件下均显示出高容量保持率。此外，所有电池均表现出接近100%的平均库仑效率。
Liquid/liquid biphasic batteries without a membrane could be promising models of redox flow batteries. However, such batteries inherently undergo self-discharge at the liquid/liquid interface, resulting in a low Coulombic efficiency and poor capacity retention. Herein, we report a triphasic system comprising all-nonaqueous electrolytes to overcome the challenges in biphasic systems. By incorporation of a third electrolyte layer to separate the anolyte and catholyte, the system effectively impeded the self-discharge event without compromising the Coulombic efficiency and capacity retention. Li metal anode and phenothiazine derivativeC18-PTZ(0.5 M) cathode have been used to construct the electrochemical cell. Moreover, we have designed two all-nonaqueous triphasic models either stacking the phases vertically or physically separating two phases sidewise along with a common interfacial layer at the top. Interestingly, both designs showed high capacity retention under static (∼98%, 31 days, 100 cycles) and flow (∼99%, 39 days, 100 cycles) conditions. Moreover, all batteries exhibited an average Coulombic efficiency of nearly 100%.