当前位置: X-MOL 学术Small › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Densely Populated Bismuth Nanosphere Semi-Embedded Carbon Felt for Ultrahigh-Rate and Stable Vanadium Redox Flow Batteries.
Small ( IF 13.0 ) Pub Date : 2020-08-12 , DOI: 10.1002/smll.201907333
Xuelong Zhou 1 , Xiangyang Zhang 1 , Lanlan Mo 1 , Xuechang Zhou 1 , Qixing Wu 1
Affiliation  

The elaborate spatial arrangement and immobilization of highly active electrocatalysts inside porous substrates are crucial for vanadium redox flow batteries capable of high‐rate charging/discharging and stable operation. Herein, a type of bismuth nanosphere/carbon felt is devised and fabricated via the carbothermic reduction of nanostructured bismuth oxides. The bismuth nanospheres with sizes of ≈25 nm are distributed on carbon fiber surfaces in a highly dispersed manner and its density reaches up to ≈500 pcs µm−2, providing abundant active sites. Besides, a unique bismuth nanosphere semi‐embedded carbon fiber structure with strong interfacial BiC chemical bonding is spontaneously formed during carbothermic reactions, offering an excellent mechanical stability under flowing electrolytes. It shows that the bismuth nanosphere semi‐embedded carbon felt can effectively promote V(II)/V(III) redox reactions with appreciable catalytic activity. The battery with the present electrode sustains an energy efficiency of 77.1 ± 0.2% and an electrolyte utilization of 57.2 ± 0.2% even when a current density up to 480 mA cm−2 is applied, which are remarkably higher than those of batteries with the bismuth nanoparticle/carbon felt synthesized by the electrodeposition method (62.6 ± 0.1%, 23.6 ± 0.2%). Further, the battery with the present electrode demonstrates a stable energy efficiency retention of 98.2% after 1000 cycles.

中文翻译:

人口稠密的铋纳米球半嵌入式碳毡,用于超高速率和稳定的钒氧化还原液流电池。

精细的空间布置和高活性电催化剂在多孔基材内部的固定化对于能够实现高速率充电/放电和稳定运行的钒氧化还原液流电池至关重要。在此,通过纳米结构化的铋氧化物的碳热还原,设计和制造了一种铋纳米球/碳毡。≈25nm的铋纳米球以高度分散的方式分布在碳纤维表面上,其密度高达≈500pcs µm -2,提供了丰富的活性位点。此外,一个唯一的铋纳米球半嵌入碳纤维结构体具有强界面毕在碳热反应过程中会自发形成C化学键,在流动的电解液下具有出色的机械稳定性。结果表明,铋纳米球半包埋碳毡可以有效地促进V(II)/ V(III)氧化还原反应,并具有明显的催化活性。具有本电极的电池即使施加了高达480 mA cm -2的电流密度,也能保持77.1±0.2%的能量效率和57.2±0.2%的电解质利用率,这明显高于含铋电池的电池。通过电沉积方法合成的纳米颗粒/碳毡(62.6±0.1%,23.6±0.2%)。此外,具有本发明电极的电池在1000次循环后显示出98.2%的稳定的能量效率保持率。
更新日期:2020-09-18
down
wechat
bug