Department of Chemical Engineering and Waterloo Institute of Nanotechnology , University of Waterloo , Waterloo N2L 3G1 , Ontario , Canada.
School of Materials Science and Engineering, Beijing Key Laboratory of Environmental Science and Engineering , Beijing Institute of Technology , Beijing 100081 , China.
ACS Appl Mater Interfaces. 2018 Oct 31;10(43):37110-37118. doi: 10.1021/acsami.8b13744. Epub 2018 Oct 17.
Low conductivity and structural degradation of LiMnO lead to poor power capability and severe capacity fading of hybrid aqueous Zn/LiMnO battery. Here, we propose an effective strategy by tuning the microstructures of graphene to optimize its electrical and interfacial properties and electrode dynamics of LiMnO/graphene cathodes, which successfully prompt significant improvements in electrical conductivity and structural stability, thus essentially leading to a promising electrochemical performance. More importantly, it reveals different electrochemical properties prompted by different conductivity, which mainly depends on the microstructures of graphene. This dependence is due to the influence of electronic channels and conductive paths on the conductivity of LiMnO/graphene electrodes. A well-designed mesoporous graphene composed of about two graphene-layers exhibits an excellent high-rate performance; even after 300 cycles, a highly reversible capacity of 75 mAh g is retained at 4C rate. The results of this study suggest that the structural tuning of electronic channels of graphene can be used as an effective means to improve the performance of LiMnO cathodes in hybrid aqueous batteries.
低电导率和结构降解导致 LiMnO 混合水系 Zn/LiMnO 电池的功率性能差和严重的容量衰减。在这里，我们通过调整石墨烯的微结构来优化其电性能和界面性质以及 LiMnO/石墨烯正极的电极动力学，提出了一种有效的策略，这成功地显著提高了电导率和结构稳定性，从而从根本上实现了有前景的电化学性能。更重要的是，它揭示了不同电导率所带来的不同电化学性能，这主要取决于石墨烯的微结构。这种依赖性是由于电子通道和导电路径对 LiMnO/石墨烯电极电导率的影响。由约两层石墨烯组成的设计良好的介孔石墨烯表现出优异的高倍率性能；即使在 300 次循环后，在 4C 倍率下仍保持 75 mAh g 的高可逆容量。这项研究的结果表明，对石墨烯电子通道结构的调整可以作为一种有效手段来提高混合水系电池中 LiMnO 正极的性能。
