Institute for Materials Research, Hasselt University, BE-3590 Diepenbeek, Belgium.
Max-Planck Institut für Eisenforschung GmbH, 40237 Düsseldorf, Germany.
Nat Commun. 2016 Aug 26;7:12693. doi: 10.1038/ncomms12693.
Interfaces are essential in electrochemical processes, providing a critical nanoscopic design feature for composite electrodes used in Li-ion batteries. Understanding the structure, wetting and mobility at nano-confined interfaces is important for improving the efficiency and lifetime of electrochemical devices. Here we use a Surface Forces Apparatus to quantify the initial wetting of nanometre-confined graphene, gold and mica surfaces by Li-ion battery electrolytes. Our results indicate preferential wetting of confined graphene in comparison with gold or mica surfaces because of specific interactions of the electrolyte with the graphene surface. In addition, wetting of a confined pore proceeds via a profoundly different mechanism compared with wetting of a macroscopic surface. We further reveal the existence of molecularly layered structures of the confined electrolyte. Nanoscopic confinement of less than 4-5 nm and the presence of water decrease the mobility of the electrolyte. These results suggest a lower limit for the pore diameter in nanostructured electrodes.
界面在电化学过程中至关重要，为锂离子电池中使用的复合电极提供了关键的纳米设计特征。了解纳米受限界面的结构、润湿性和迁移率对于提高电化学器件的效率和寿命非常重要。在这里，我们使用表面力仪来量化锂离子电池电解液对纳米受限石墨烯、金和云母表面的初始润湿。我们的结果表明，由于电解液与石墨烯表面的特定相互作用，受限石墨烯优先润湿，而不是金或云母表面。此外，与润湿宏观表面相比，受限孔的润湿过程通过一种截然不同的机制进行。我们进一步揭示了受限电解液中存在分子层状结构。纳米尺度的小于 4-5nm 的限制和水的存在降低了电解质的迁移率。这些结果表明纳米结构电极的孔径存在下限。
