Performance Enhancement and Side Reactions in Rechargeable Nickel-Iron Batteries with Nanostructured Electrodes
Performance Enhancement and Side Reactions in Rechargeable Nickel-Iron Batteries with Nanostructured Electrodes
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DOI：
10.1021/acsami.5b10547
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发表时间：
2016-01-27
影响因子：
9.5
通讯作者：
Yushin, Gleb
中科院分区：
文献类型：
--
作者：
Lei, Danni;Lee, Dong-Chan;Yushin, Gleb
我们报告的第一次强耦合nanoFe/多壁碳纳米管（MWCNT）和nanoNiO/MWCNT纳米复合材料的溶液为基础的合成用作可充电碱性Ni-Fe电池的阳极和阴极。所生产的水性电池表现出非常高的放电容量（在200 mA g（-1）电流密度下为800 mAh g（Fe）（-1）），其在可比的电流密度下超过商业Ni-Fe电池近1个数量级。这些电池还显示出缺乏任何“活化”，这在商业电池中是典型的，其中低初始容量在初始20-50次循环期间缓慢增加。高导电性MWCNT网络的使用允许高容量利用，因为快速且有效的电子传输到氧化态[如Fe（OH）（2）或Fe 3 O 4]的活性金属纳米颗粒。多壁碳纳米管的柔性性质适应在金属电极中伴随还原氧化反应的相变期间发生的显著体积变化。同时，我们报告和讨论了活性纳米颗粒的高表面积导致多种副反应。Fe阳极的溶解导致显著更大的阳极颗粒的再沉淀。Ni阴极的溶解导致Ni金属在阳极上沉淀，从而阻断OH-阴离子的传输。电解质的摩尔浓度和组成对容量利用率和循环稳定性有显著影响。
We report for the first time a solution-based synthesis of strongly coupled nanoFe/multiwalled carbon nanotube (MWCNT) and nanoNiO/MWCNT nanocomposite materials for use as anodes and cathodes in rechargeable alkaline Ni-Fe batteries. The produced aqueous batteries demonstrate very high discharge capacities (800 mAh g(Fe)(-1) at 200 mA g(-1) current density), which exceed that of commercial Ni-Fe cells by nearly 1 order of magnitude at comparable current densities. These cells also showed the lack of any "activation", typical in commercial batteries, where low initial capacity slowly increases during the initial 20-50 cycles. The use of a highly conductive MWCNT network allows for high-capacity utilization because of rapid and efficient electron transport to active metal nanoparticles in oxidized [such as Fe(OH)(2) or Fe3O4] states. The flexible nature of MWCNTs accommodates significant volume changes taking place during phase transformation accompanying reduction oxidation reactions in metal electrodes. At the same time, we report and discuss that high surface areas of active nanoparticles lead to multiple side reactions. Dissolution of Fe anodes leads to reprecipitation of significantly larger anode particles. Dissolution of Ni cathodes leads to precipitation of Ni metal on the anode, thus blocking transport of OH-anions. The electrolyte molarity and composition have a significant impact on the capacity utilisation and cycling stability.