School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan, 689-798, Korea.
Nano Lett. 2014 Aug 13;14(8):4438-48. doi: 10.1021/nl5014037. Epub 2014 Jul 3.
The facilitation of ion/electron transport, along with ever-increasing demand for high-energy density, is a key to boosting the development of energy storage systems such as lithium-ion batteries. Among major battery components, separator membranes have not been the center of attention compared to other electrochemically active materials, despite their important roles in allowing ionic flow and preventing electrical contact between electrodes. Here, we present a new class of battery separator based on inverse opal-inspired, seamless nanoscaffold structure ("IO separator"), as an unprecedented membrane opportunity to enable remarkable advances in cell performance far beyond those accessible with conventional battery separators. The IO separator is easily fabricated through one-pot, evaporation-induced self-assembly of colloidal silica nanoparticles in the presence of ultraviolet (UV)-curable triacrylate monomer inside a nonwoven substrate, followed by UV-cross-linking and selective removal of the silica nanoparticle superlattices. The precisely ordered/well-reticulated nanoporous structure of IO separator allows significant improvement in ion transfer toward electrodes. The IO separator-driven facilitation of the ion transport phenomena is expected to play a critical role in the realization of high-performance batteries (in particular, under harsh conditions such as high-mass-loading electrodes, fast charging/discharging, and highly polar liquid electrolyte). Moreover, the IO separator enables the movement of the Ragone plot curves to a more desirable position representing high-energy/high-power density, without tailoring other battery materials and configurations. This study provides a new perspective on battery separators: a paradigm shift from plain porous films to pseudoelectrochemically active nanomembranes that can influence the charge/discharge reaction.
促进离子/电子传输，以及对高能量密度的需求不断增加，是推动锂离子电池等储能系统发展的关键。在主要的电池组件中，与其他电化学活性材料相比，分离膜并没有得到太多关注，尽管它们在允许离子流动和防止电极之间的电接触方面起着重要作用。在这里，我们提出了一种基于反蛋白石启发的、无缝纳米支架结构的新型电池分离器（“IO 分离器”），作为一个前所未有的膜机会，可以实现电池性能的显著进步，远远超过传统电池分离器所能达到的水平。IO 分离器可以通过在无纺基底中存在紫外（UV）可固化三丙烯酸酯单体的情况下，通过一锅法、蒸发诱导胶体二氧化硅纳米粒子自组装，然后进行 UV 交联和选择性去除二氧化硅纳米粒子超晶格来轻松制造。IO 分离器的精确有序/网状纳米多孔结构允许显著改善离子向电极的转移。IO 分离器驱动的离子输运现象的促进作用预计将在高性能电池（特别是在高质量负载电极、快速充放电和高极性液体电解质等苛刻条件下）的实现中发挥关键作用。此外，IO 分离器使 Ragone 图曲线能够移动到更理想的位置，代表高能量/高功率密度，而无需对其他电池材料和配置进行调整。这项研究为电池分离器提供了一个新的视角：从普通多孔膜到具有伪电化学活性的纳米膜的范式转变，可以影响电荷/放电反应。
