Lee Dae Kyeum, Go Chae Young, Kim Ki Chul
Computational Materials Design Laboratory, Division of Chemical Engineering , Konkuk University , Seoul 05029 , The Republic of Korea.
ACS Appl Mater Interfaces. 2019 Sep 4;11(35):31972-31979. doi: 10.1021/acsami.9b09947. Epub 2019 Aug 21.
Cyclic organic compounds with pentagon rings have been paid less attention for cathodes in lithium-ion batteries as compared with aromatic compounds. In this study, we investigate the Li-binding thermodynamics, redox properties, and theoretical performance for a selected set of heteroatom-containing, pentagon-shaped, organic compounds, namely borole, pyrrole, furan, phosphole, thiophene, and their derivatives to assess their potential for organic cathode materials. This investigation provides us with three important findings. First, the Li-binding thermodynamics and redox properties for the organic compounds would be systematically tailored by the type of the incorporated heteroatom and backbone length, exhibiting both the strongest Li-binding and the highest redox potential for borole. Second, it is highlighted that borole can store up to two Li atoms per molecule exhibiting the exceptionally high charge capacity (839 mA h/g) despite the absence of any well-known redox-active moieties (e.g., carbonyl). Third, dibenzothiophene exhibits weak and comparable Li-binding strengths at multiple feasible binding configurations with an indication of its low Li-storage capability, while the others dominantly bind with Li at their most stable binding configurations. All these findings will provide an insight into the guidelines for the systematic design of promising heterocyclic organic compounds (i.e., borole-based insoluble polymeric forms) for cathodes in secondary batteries.
与芳香族化合物相比，含五元环的环状有机化合物作为锂离子电池的阴极受到的关注较少。在本研究中，我们研究了一组选定的含杂原子的五边形有机化合物，即硼咯、吡咯、呋喃、磷咯、噻吩及其衍生物的锂结合热力学、氧化还原性质和理论性能，以评估它们作为有机阴极材料的潜力。这项研究为我们提供了三个重要发现。首先，有机化合物的锂结合热力学和氧化还原性质将通过引入的杂原子类型和主链长度进行系统调整，硼咯表现出最强的锂结合能力和最高的氧化还原电位。其次，值得注意的是，尽管硼咯没有任何众所周知的氧化还原活性基团（如羰基），但每个分子最多可存储两个锂原子，表现出极高的电荷容量（839 mA h/g）。第三，二苯并噻吩在多种可行的结合构型下表现出较弱且相当的锂结合强度，表明其锂存储能力较低，而其他化合物在其最稳定的结合构型下主要与锂结合。所有这些发现将为系统设计用于二次电池阴极的有前景的杂环有机化合物（即基于硼咯的不溶性聚合物形式）提供指导。
