Electrochemical tuning of layered lithium transition metal oxides for improvement of oxygen evolution reaction
Electrochemical tuning of layered lithium transition metal oxides for improvement of oxygen evolution reaction
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DOI：
10.1038/ncomms5345
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发表时间：
2014-07-01
影响因子：
16.6
通讯作者：
Cui, Yi
中科院分区：
文献类型：
--
作者：
Lu, Zhiyi;Wang, Haotian;Cui, Yi
由于析氧反应在清洁能源生产和储存中的重要性，一直在积极寻求用于析氧反应的低成本和高效催化剂。虽然开发新的催化剂很重要，但在广泛的电化学电势范围内调整现有催化剂的电子结构也可以提供新的方向。在这里，我们展示了一种方法，用于电化学锂调谐的催化材料在有机电解质中，随后在水溶液中的催化活性的增强。通过将锂离子电池中常用的正极材料LiCoO 2中的锂离子连续萃取到有机电解液中的Li0.5CoO2中，催化活性显著提高。这种增强归因于脱锂过程后的独特电子结构。该方法的一般功效在具有类似改进的几种混合金属氧化物中得到证明。电化学脱锂的LiCo0.33Ni0.33Fe0.33O2表现出显著的性能，优于基准铱/碳催化剂。
Searching for low-cost and efficient catalysts for the oxygen evolution reaction has been actively pursued owing to its importance in clean energy generation and storage. While developing new catalysts is important, tuning the electronic structure of existing catalysts over a wide electrochemical potential range can also offer a new direction. Here we demonstrate a method for electrochemical lithium tuning of catalytic materials in organic electrolyte for subsequent enhancement of the catalytic activity in aqueous solution. By continuously extracting lithium ions out of LiCoO2, a popular cathode material in lithium ion batteries, to Li0.5CoO2 in organic electrolyte, the catalytic activity is significantly improved. This enhancement is ascribed to the unique electronic structure after the delithiation process. The general efficacy of this methodology is demonstrated in several mixed metal oxides with similar improvements. The electrochemically delithiated LiCo0.33Ni0.33Fe0.33O2 exhibits a notable performance, better than the benchmark iridium/carbon catalyst.