Strong metal oxide-support interactions in carbon/hematite nanohybrids activate novel energy storage modes for ionic liquid-based supercapacitors
Strong metal oxide-support interactions in carbon/hematite nanohybrids activate novel energy storage modes for ionic liquid-based supercapacitors
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DOI：
10.1016/j.ensm.2019.04.035
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发表时间：
2019-07-01
影响因子：
20.4
通讯作者：
Oschatz, Martin
中科院分区：
文献类型：
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作者：
Lai, Feili;Feng, Jianrui;Oschatz, Martin
强金属氧化物-载体相互作用对于激活离子液体超级电容器中碳支撑混合电极的高能量存储模式至关重要。尽管众所周知导电载体可以影响金属氧化物的电化学性能，但仍缺乏对如何利用金属氧化物-载体相互作用来优化联合储能性能的见解。我们报告了 α-Fe2O3 纳米斑点和磷掺杂有序介孔碳 (CMK-3-P) 之间的结点，具有金属氧化物的强共价锚定。 CMK-3-P-Fe2O3 中的氧化物-碳相互作用增强了 Fe2O3 和 CMK-3-P 之间的连接和电荷转移。它通过增强离子液体离子与电极表面之间的相互作用来增强能量存储。密度泛函理论模拟表明，强金属氧化物-载体相互作用将离子液体的吸附能提高至-4.77 eV，而结合较弱的CMK-3Fe(2)O(3)杂化物的吸附能为-3.85 eV。尽管比表面积较低且储能模式明显相似，但与不含 Fe2O3 的 CMK-3 和 CMK-3-P 参考材料相比，CMK-3-P-Fe2O3 表现出优异的双电层电容器性能，在 2 mV s(-1) (0-3.5 V) 下比电容为 179 F g(-1)。这种混合电极设计原理可适用于未来用于先进储能的稳定金属氧化物支撑电极的合理设计。
Strong metal oxide-support interaction is crucial to activate high energy storage modes of carbon-supported hybrid electrodes in ionic liquid-based supercapacitors. Although it is known that conductive supports can influence the electrochemical properties of metal oxides, insights into how metal oxide-support interactions can be exploited to optimize joint energy storage properties are lacking. We report the junction between alpha-Fe2O3 nanosplotches and phosphorus-doped ordered mesoporous carbon (CMK-3-P) with strong covalent anchoring of the metal oxide. The oxide-carbon interaction in CMK-3-P-Fe2O3 is strengthening the junction and charge transfer between Fe2O3 and CMK-3-P. It enhances energy storage by intensifying the interaction between ionic liquid ions and the surface of the electrode. Density functional theory simulations reveal that the strong metal oxide-support interaction increases the adsorption energy of ionic liquid to -4.77 eV as compared to -3.85 eV for a CMK-3Fe(2)O(3) hybrid with weaker binding. In spite of the lower specific surface area and apparently similar energy storage mode, the CMK-3-P-Fe2O3 exhibits superior electrical double-layer capacitor performance with a specific capacitance of 179 F g(-1) at 2 mV s(-1) (0-3.5 V) in comparison to Fe2O3-free CMK-3 and CMK-3-P reference materials. This principle for design of hybrid electrodes can be applicable for future rational design of stable metal oxide-support electrodes for advanced energy storage.