Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing University of Posts and Telecommunications , 9 Wenyuan Road , Nanjing 210023 , P. R. China.
Research Institute of Electrochemical Energy , National Institute of Advanced Industrial Science and Technology (AIST) , Ikeda , Osaka 563-8577 , Japan.
ACS Appl Mater Interfaces. 2019 Sep 25;11(38):34895-34903. doi: 10.1021/acsami.9b09722. Epub 2019 Sep 12.
Separators are key safety components for electrochemical energy storage systems. However, the intrinsic poor wettability with electrolyte and low thermal stability of commercial polyolefin separators cannot meet the requirements of the ever-expanding market for high-power, high-energy, and high-safety power systems, such as lithium-metal, lithium-sulfur, and lithium-ion batteries. In this study, scalable bendable networks built with ultralong silica nanowires (SNs) are developed as stable separators for both high-safety and high-power lithium-metal batteries. The three-dimensional porous nature (porosity of 73%) and the polar surface of the obtained SNs separators endue a much better electrolyte wettability, larger electrolyte uptake ratio (325%), higher electrolyte retention ratio (63%), and ∼7 times higher ionic conductivity than that of commercial polypropylene (PP) separators. Moreover, the pore-rich structure of the SNs separator can aid in evenly distributing lithium and, in turn, suppress the uncontrollable growth of lithium dendrites to a certain degree. Furthermore, the pure inorganic structure endows the SNs separators with excellent chemical and electrochemical stabilities even at elevated temperatures, as well as excellent thermal stability up to 700 °C. This work underpins the utilization of SNs separators as a rational choice for developing high-performance batteries with a metallic lithium anode.
分离器是电化学储能系统的关键安全组件。然而，商用聚烯烃隔板与电解质的固有润湿性差，热稳定性低，无法满足日益扩展的高功率、高能量、高安全性电力系统（如锂金属、锂硫和锂离子电池）的要求。在这项研究中，开发了具有超长二氧化硅纳米线（SNs）的可扩展的柔韧网络，作为高安全性和高功率锂金属电池的稳定隔板。所得到的 SNs 隔板的三维多孔性质（孔隙率为 73%）和极性表面赋予其更好的电解质润湿性、更大的电解质吸收比（325%）、更高的电解质保持率（63%）和约 7 倍于商业聚丙烯（PP）隔板的离子电导率。此外，SNs 隔板的多孔结构有助于均匀分布锂，并在一定程度上抑制锂枝晶的不可控生长。此外，纯无机结构使 SNs 隔板具有优异的化学和电化学稳定性，即使在高温下，也具有优异的热稳定性，高达 700°C。这项工作为 SNs 隔板作为开发具有金属锂阳极的高性能电池的合理选择提供了依据。
