Promoting Pore-Level Mass Transport/Reaction in Flow Batteries: Bi Nanodot/Vertically Standing Carbon Nanosheet Composites on Carbon Fibers
Promoting Pore-Level Mass Transport/Reaction in Flow Batteries: Bi Nanodot/Vertically Standing Carbon Nanosheet Composites on Carbon Fibers
复制标题
促进液流电池中的孔隙级传质/反应：碳纤维上的双纳米点/垂直站立碳纳米片复合材料
DOI：
10.1021/acsami.1c08494
复制
发表时间：
2021
影响因子：
9.5
通讯作者：
Zhou Xuelong
中科院分区：
文献类型：
--
作者：
Zhang Xiangyang;Ye Xiaolin;Huang Shaopei;Zhou Xuelong
精细的毡电极纳米结构固/液界面设计可以说是促进氧化还原液流电池的孔级传输-反应过程的最有效途径。在此，我们设想了一种新型的纳米催化剂层结构的石墨毡通过引入垂直站立的碳纳米片限制的Bi纳米点到碳纤维表面。垂直站立的碳纳米片构造具有用于钒离子穿梭的直通道的纳米多孔层，其中高度分散的Bi纳米点被刚性地限制以提供丰富的活性位点。采用合理设计的电极的钒氧化还原液流电池在150 mA cm-2下达到89%的能量效率，这显著高于生毡（61%）和氧化毡（77%）。此外，具有本电极的电池即使在400 mA cm-2下也保持超过73%的能量效率，显示出优异的耐受快速充电和放电的能力。多物理场模拟表明，垂直站立的架构优化了钒离子的访问固/液界面，从而最大限度地提高催化活性。此外，该电池可以维持超过1000次循环而没有明显的效率衰减，证实了本电极的极好的稳定性。这些令人鼓舞的结果表明，用定制的组合物设计垂直直立结构可能为推进液流电池技术开辟新的途径。
Elaborate nanoarchitectured solid/liquid interface design of felt electrodes is arguably the most effective pathway to promote the pore-level transport-reaction processes of redox flow batteries. Herein, we conceive a new type of nanocatalytic-layer-architectured graphite felt via introducing the vertically standing carbon nanosheet-confined Bi nanodots onto carbon fiber surfaces. The vertically standing carbon nanosheets construct a nanoporous layer with straight channels for vanadium ion shuttling, where highly dispersed Bi nanodots are stiffly confined to afford abundant active sites. The vanadium redox flow battery utilizing the rationally designed electrodes achieves an energy efficiency of 89% at 150 mA cm–2, which is substantially higher than those of raw felt (61%) and oxidized felt (77%). Also, the battery with the present electrode maintains an energy efficiency of over 73% even at 400 mA cm–2, showing the excellent capability of withstanding fast charging and discharging. The multiphysics simulation shows that the vertically standing architecture optimizes the vanadium ion accessibility to the solid/liquid interfaces and thus maximizes the catalytic activity. Moreover, the battery can sustain more than 1000 cycles without obvious efficiency decay, confirming the superb stability of the present electrode. These encouraging results indicate that engineering vertically standing structures with tailored compositions may open up new avenues for advancing the flow battery technology.