Electrolytic synthesis of carbon from the captured CO2 in molten LiCl-KCl-CaCO3: Critical roles of electrode potential and temperature for hollow structure and lithium storage performance
Electrolytic synthesis of carbon from the captured CO2 in molten LiCl-KCl-CaCO3: Critical roles of electrode potential and temperature for hollow structure and lithium storage performance
复制标题
从熔融 LiCl-KCl-CaCO3 中捕获的 CO2 电解合成碳：电极电位和温度对中空结构和锂存储性能的关键作用
DOI：
10.1016/j.electacta.2017.11.025
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发表时间：
2018-01-01
影响因子：
6.6
通讯作者：
Wang, Dihua
中科院分区：
文献类型：
--
作者：
Deng, Bowen;Tang, Juanjuan;Wang, Dihua
在本研究中，含CaCO 3的熔融LiCleKCl在CO2气氛下作为电解质用于制备电解炭进行了研究。改变电极电位和电解温度可以操纵碳的电沉积反应的动力学，从而允许形成具有不同形态的碳产物。在450 ℃下，分别在2.8和3.5 V的电池电压下获得了微米级中空碳球（HCS）和碳纳米片的高产率。在较高的温度（550和650摄氏度）和电池电压下，碳片的含量减少，可以观察到各种碳材料，如准球形颗粒，珊瑚状碳和碳纳米纤维。只有在中等反应速率（2.8V和450 ℃）下才能得到100 - 100 μ m大小的HCS，这使得所形成的CO气体（碳酸根离子电还原的中间体之一）发生微泡效应。CO气体的膨胀使塑性的碳纤维片成形，从而形成发育良好的HCS。在碳产品中，在4.5 V和650 ℃下沉积的碳产品表现出超过400 m2 g-1的最高比表面积，而HCS表现出最佳的锂储存性能。本研究强调了控制电极电位和工作温度对从熔盐中捕获的CO2制备增值电解炭的重要性。(C)2017爱思唯尔有限公司版权所有
In the present study, CaCO3-containing molten LiCleKCl under CO2 atmosphere was investigated as the electrolyte for the preparation of electrolytic carbon. Varying the electrode potential and electrolysis temperature can manipulate the kinetics of the electro-deposition reaction of carbon, thereby allowing the formation of the carbon products with different morphologies. At 450 degrees C, high yields of micron-sized hollow carbon spheres (HCSs) and ultrathin sheets were obtained under 2.8 and 3.5 V cell voltages, respectively. At higher temperatures (550 and 650 degrees C) and cell voltages, the content of carbon sheets decreased, and various carbon materials, such as quasi-spherical particles, coral-like carbon and carbon nanofibers, could be observed. Micron-sized HCSs were only obtained with a moderate reaction rate (2.8 V and 450 degrees C), which allowed the occurrence of microbubble effect of the as-formed CO gas (one of the intermediates of electro-reduction of carbonate ions). The expansion of the CO gas shaped the plastic ultrathin carbon sheets, resulting in the formation of well-developed HCSs. Among the carbon products, the one deposited at 4.5 V and 650 degrees C exhibited the highest specific surface area of more than 400 m(2) g(-1), while the HCSs showed the best performance for lithium storage. The present study highlights the importance of manipulating electrode potential and working temperature to the preparation of value-added electrolytic carbon from the captured CO2 in molten salts. (C) 2017 Elsevier Ltd. All rights reserved.