Ultrathin and Ultrastrong Kevlar Aramid Nanofiber Membranes for Highly Stable Osmotic Energy Conversion

作者：Ding, Li; Xiao, Dan; Zhao, Zihao; Wei, Yanying; Xue, Jian^*; Wang, Haihui^*

来源：Advanced Science, 2022, 9(25): 2202869.

DOI：10.1002/advs.202202869

• ion selective
• Kevlar aramid nanofiber
• membrane
• nanofluidic
• osmotic energy

An ion-selective membrane can directly convert the osmotic energy to electricity through reverse electrodialysis. However, developing an advanced membrane that simultaneously possesses high power density, excellent mechanical strength, and convenient large-scale production for practical osmotic energy conversion, remains challenging. Here, the fabrication of ultrathin and ultrastrong Kevlar aramid nanofiber (KANF) membranes with interconnected three-dimensional (3D) nanofluidic channels via a simple blade coating method is reported. The negatively charged 3D nanochannels show typical surface-charge-governed nanofluidic ion transport and exhibit excellent cation selectivity. When applied to osmotic energy conversion, the power density of the KANF membrane-based generator reaches 4.8 W m(-2) (seawater/river water) and can be further increased to 13.8 W m(-2) at 328 K, which are higher than most of the state-of-the-art membranes. Importantly, a 4-mu m-thickness KANF membrane shows ultrahigh tensile strength (565 MPa) and Young's modulus (25 GPa). This generator also exhibits ultralong stability over 120 days, showing great potential in practical energy conversions.

• 单位
  清华大学