Performance of Thixotropic Gel Electrolytes in the Rechargeable Aqueous Zn/LiMn2O4 Battery

Novel aqueous gel electrolytes have been prepared using a combination of thixotropic and nonthixotropic gelling agents. These gels are used in rechargeable hybrid aqueous batteries for the first time. Thermogravimetric analysis proves that the retentions of the gel electrolytes in the absorbed glass mat (AGM) separator are significantly higher than that of the conventional liquid electrolyte. Batteries with the gel electrolytes exhibit up to 10% improvement in specific reversible capacity and higher rate capability, and the capacity retention is up to 8% higher than that of the reference battery after 1000 cycles at 4 C. Furthermore, the electrodes of the gel batteries are well-preserved, and dendrite formation on the Zn anode is suppressed as confirmed by scanning electron microscopy and chronoamperometry techniques. These significant improvements are due to the new gel electrolytes and the synergistic effect of a thixotropic and a nonthixotropic gelling agent.