Preparation of Carbon Nanotubes/Manganese Dioxide Composite Catalyst with Fewer Oxygen-Containing Groups for Li-O-2 Batteries Using Polymerized Ionic Liquids as Sacrifice Agent
Preparation of Carbon Nanotubes/Manganese Dioxide Composite Catalyst with Fewer Oxygen-Containing Groups for Li-O-2 Batteries Using Polymerized Ionic Liquids as Sacrifice Agent
复制标题
以聚合离子液体为牺牲剂制备含较少氧基团的碳纳米管/二氧化锰复合催化剂用于Li-O-2电池
DOI：
10.1021/acsami.6b16531
复制
发表时间：
2017
影响因子：
9.5
通讯作者：
Deng Youquan
中科院分区：
文献类型：
--
作者：
Ni Wenpeng;Liu Shimin;Fei Yuqing;He Yude;Ma Xiangyuan;Lu Liujin;Deng Youquan
考虑到含氧基团对碳电极表面的显着影响，采用聚合离子液体（PIL）作为牺牲剂，采用简便的方法合成了碳纳米管（CNT）基MnO2复合催化剂。在此，制备了PIL（聚合疏水性1-乙烯基-3-乙基咪唑鎓双（（三氟甲基）磺酰基）亚胺）包裹的CNT。该复合材料通过KMnO4溶液处理来负载MnO2，利用PIL与KMnO4之间的反应，排除或抑制CNT的氧化，并且所合成的含氧基团较少的材料作为Li-O2电池的阴极催化剂，直接避免了粘合剂的使用。与不含 PIL 的样品相比，该催化剂表现出增强的活性，放电和充电期间较低的过电势（100 mA g-1 电流密度下为 0.97 V）证实了这一点。同时，使用该催化剂的Li-O2电池的库仑效率和倍率性能等性能参数也得到了改善。此外，由于MnO2的固有催化活性和催化剂表面上较少的氧官能团的协同效应，受限Li2O2颗粒的形成可能是Li-O2电池充电电位降低的原因。
Considering the significant influence of oxygen-containing groups on the surface of carbon involved electrodes, a carbon nanotube (CNT)-based MnO2composite catalyst was synthesized following a facile method while using polymerized ionic liquids (PIL) as sacrifice agent. Herein, the PIL (polymerized hydrophobic 1-vinyl-3-ethylimidazolium bis ((trifluoromethyl)sulfonyl)imide) wrapped CNTs were prepared. The composite was applied to support MnO2by the treatment of KMnO4solution, taking advantage of the reaction between PIL and KMnO4, which excludes or suppresses the oxidation of CNTs, and the as-synthesized material with fewer oxygen-containing groups acted as a cathode catalyst for Li-O2batteries, directly avoiding the application of binders. The catalyst shows enhanced activity compared to that of the samples without PIL, as verified by the lower overpotential during discharging and charging (0.97 V at the current density of 100 mA g–1). Meanwhile, the performance parameters such as Coulombic efficiency and rate capability were also improved for the Li-O2battery utilizing this catalyst. Further, the formation of confined Li2O2particles could be responsible for the reduction of charge potential of Li-O2batteries due to the synergy effect of the intrinsic catalytic activity of MnO2and fewer oxygen functional groups on the catalyst surface.