Construction of electrospun multistage ZnO@PMIA gel electrolytes for realizing high performance zinc-ion batteries

Abstract

As an important component of ZIBs, flexible gel electrolytes offer the advantages of solid/liquid electrolytes and good interfacial bonding. However, limited by poor ionic conductivity and mechanical properties, traditional gel electrolytes are still unable to meet realistic applications. To solve the above problems, in this paper, poly(m-phenylene isophthalamide) (PMIA) nanofiber membranes were prepared by electrospinning, and then ordered zinc oxide (ZnO) nanorods were grown on their surfaces by hydrothermal method, and ZnO@PMIA nanofiber membranes were combined with poly(vinyl alcohol) (PVA) gel to obtain ZnO@PMIA-PVA (ZPP) composite electrolytes. On the one hand, thanks to the advantages of large specific surface area and good electrical conductivity of PMIA nanofibers and ZnO nanorods, they can provide continuous and uniform transmission channels for Zn²⁺ .On the other hand, ZPP combines the nanofiber layer with the gel layer, which possesses excellent mechanical properties and produces a well-bonded interface with the electrode, which can effectively reduce the internal resistance and resist the penetration of the dendrimer into the electrolyte during long cycling. The results show that the ZPP composite electrolyte has a high ionic conductivity (18.3 mS·cm^-1) and exhibits obvious advantages in inhibiting hydrogen precipitation and oxidative decomposition of Zn anode, and the Zn/ZPP/Zn symmetric battery can be recycled for >1000 h at 3 mA·cm^-2, and the full battery Zn/ZPP/MnO₂ can still maintain 159.3 mAh·g^-1 residual capacity after 1000 cycles with stable long-cycle performance and high coulombic efficiency (CE) (99 %). This flexible composite electrolyte has high safety, mechanical and electrochemical properties, which can realize high-performance ZIBs, and is expected to provide a new strategy for next-generation wearable energy storage devices.