Modulation of zinc deposition behaviour by electrostatically spun PAN-ZnTFSI fibre layer on separator for aqueous zinc ion batteries

Aqueous zinc ion batteries (AZIBs) are well-suited for current energy storage technologies due to their high safety and low cost. However, battery failures resulting from dendrites and side reactions restrict their widespread application. Here, we designed a polyacrylonitrile (PAN) -zinc trifluoromethanesulfonate (ZnTFSI) nanofibre synergistic glass fibre (PZ-GF) to modulate the interfacial deposition kinetics. The effective coordination of numerous CN functional groups within PZ, in conjunction with Zn2+, results in the homogeneous dispersion of the electric field across the electrode, which promotes the uniform deposition of Zn2+ on the zinc anode and thus significantly inhibits the rapid growth of zinc dendrites. ZnTFSI is hydrophilic and has strong hydrogen bonding interactions with the H2O molecule so that the separator can be used as a molecular sieve to regulate the flux of H2O, promote the desolvation of hydrated zinc ions, and inhibit side reactions.Tests of the initial nucleation overpotential of the symmetric battery and calculation of the activation energy reflect that PZ-GF has a smaller nucleation energy barrier and enhanced kinetic effect. And the zinc symmetric battery with PZ-GF film shows an ultra-long cycle stability of 1200 cycles with a capacity retention of 75% even at 0.5 A g-1 for the Zn//VO2 full cells.