In situ imaging electrocatalytic CO2 reduction and evolution reactions in all-solid-state Li-CO2 nanobatteries
In situ imaging electrocatalytic CO2 reduction and evolution reactions in all-solid-state Li-CO2 nanobatteries
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全固态Li-CO2纳米电池中电催化CO2还原和析出反应的原位成像
DOI：
10.1039/d0nr07066a
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发表时间：
2020-12-21
期刊：
影响因子：
6.7
通讯作者：
Huang, Jianyu
中科院分区：
文献类型：
--
作者：
Yang, Tingting;Li, Hui;Huang, Jianyu
Li-CO2电池由于其高能量密度和可能的CO2捕获应用而成为有前途的能量存储装置。然而，在Li-CO2电池的实际应用之前，仍然需要解决一些关键问题，例如由Li 2CO 3放电产物的缓慢分解引起的高充电过电位和差的循环稳定性。探索高效的CO2还原反应（CORR）和析氢反应（COER）催化剂并了解其催化机理对于Li-CO2电池的应用至关重要。然而，在CORR和COER期间的电催化的直接成像仍然是难以捉摸的。在此，我们报告了在先进的像差校正的环境透射电子显微镜中使用Ni-Ru涂层的α-MnO 2纳米线（Ni-Ru/MnO 2）阴极的Li-CO 2纳米电池中的CORR和COER期间的电催化的原位成像。在CORR过程中，Ni-Ru/MnO 2纳米线表面通过4Li（+）+3CO（2）+4e（-）-> 2Li（2）CO（3）+ C形成了一层较厚的Li 2CO 3和碳的混合层。在COER过程中，生成的Li 2CO 3分解为2Li（2）CO（3）-> 2CO（2）+ O-2 + 4Li（+）+4 e（-），而生成的无定形碳保留下来。相比之下，Li 2CO 3在裸露的MnO 2纳米线上的分解是困难的，强调了重要的Ni-Ru纳米线在促进COER中的电催化作用。我们的研究结果提供了对Li-CO2电池中CO2化学的重要理解，可能有助于设计用于储能应用的Li-CO2电池。
Li-CO2 batteries are promising energy storage devices owing to their high energy density and possible applications for CO2 capture. However, still some critical issues, such as high charging overpotential and poor cycling stability caused by the sluggish decomposition of Li2CO3 discharge products, need to be addressed before the practical applications of Li-CO2 batteries. Exploring highly efficient catalysts and understanding their catalytic mechanisms for the CO2 reduction reaction (CORR) and evolution reaction (COER) are critical for the application of Li-CO2 batteries. However, the direct imaging of electrocatalysis during CORR and COER is still elusive. Herein, we report the in situ imaging of electrocatalysis during CORR and COER in a Li-CO2 nanobattery using a Ni-Ru-coated alpha-MnO2 nanowire (Ni-Ru/MnO2) cathode in an advanced aberration corrected environmental transmission electron microscope. During the CORR, a thick Li2CO3 and carbon mixture layer was formed on the surface of the Ni-Ru/MnO2 nanowires via 4Li(+) + 3CO(2) + 4e(-) -> 2Li(2)CO(3) + C. During the COER, the as-formed Li2CO3 decomposed via 2Li(2)CO(3) -> 2CO(2) + O-2 + 4Li(+) + 4e(-), while the as-formed amorphous carbon remained. In contrast, the decomposition of Li2CO3 on bare MnO2 nanowires was difficult, underscoring the important Ni-Ru bimetal electrocatalytic role in facilitating the COER. Our results provide an important understanding of the CO2 chemistry in Li-CO2 batteries, possibly helping in the designing of Li-CO2 batteries for energy storage applications.