Improving Performance and Cyclability of Printed Flexible Zinc-Air Batteries Using Carbopol Gel Electrolyte

Abstract

The formation of dendritic zinc during recharge is a critical issue hindering the widespread application of rechargeable zinc-air batteries. Here, we demonstrate that the dendritic growth of zinc can be effectively suppressed using Carbopol gel electrolyte. This work investigates the effects of the concentration of Carbopol (0-3.5 wt.%) on polarization characteristic and a discharge/recharge profile of the batteries. Moreover, the morphology of the zinc anodes and their electrochemical parameters were examined as a function of cycling. The gel electrolyte significantly changes the anode/electrolyte interface and affects the nucleation and growth of zinc, resulting in effective inhibition of zinc dendrites. Therefore, cyclability of the batteries was considerably enhanced. However, increasing the concentration of Carbopol leaded to increasing the internal resistance of the batteries but a reduction in resistance at the electrode/electrolyte interface.

Pursuit of reversible Zn electrochemistry: a time-honored challenge towards low-cost and green energy storage

“…A series of PVA/PAA composite electrolytes incorporated with KOH were investigated, and the highest ion conductivity reached 301 mS cm −1 at room temperature, with a weight ratio of PVA/PAA = 10/7.5 108 . Chaduang et al 109 reported that 3.5 wt% crosslinked PAA in GPEs could obviously change the anode/electrolyte interface structure, preventing the nucleation and growth of Zn dendrites and reducing the interface resistance. A PAA electrolyte neutralized by NaOH could support more than 50 times its own weight of salt solution (0.2 M Zn(CH 3 COO) 2 and 6 M KOH) at equilibrium and has been used in a variety of batteries [110][111][112] .…”

Mapping the Design of Electrolyte Materials for Electrically Rechargeable Zinc–Air Batteries

“…[ 22 ] A GPE consisting of Carbopol and 8 m KOH aqueous solution was beneficial for obtaining a zinc boulder structure on the electrode surface with no dendrite formation after the first cycle. [ 135 ]…”

“…As ion‐conductive GPEs can also serve as a separator membrane, they can suppress Zn(OH) 4 2− crossover, which can affect the nucleation and growth of zinc and alleviate the dissolution of active materials owing to their low water contents. [ 135,136 ] A PVA–PAA–KOH GPE with bicontinuous phases was designed to integrate a 3D interconnected anion‐conducting phase with a 3D reticulated anion‐repelling phase ( Figure a). [ 137 ] This unique structure enabled the GPE to serve as a selective ion transport channel that can effectively suppressed Zn(OH) 4 2− crossover through ion repulsion (i.e., Donnan exclusion effect) by the continuous Nafion phase while slightly impairing OH − migration (predominantly by the PVA/PAA nanofiber mat).…”

“…[22] A GPE consisting of Carbopol and 8 m KOH aqueous solution was beneficial for obtaining a zinc boulder structure on the electrode surface with no dendrite formation after the first cycle. [135] Moreover, according to the operating mechanism of ERZABs, the intermediate Zn(OH) 4 2− ions result from oxidized zinc ions (Zn 2+ ) that subsequently react with OH − ions during the discharge process. Driven by the concentration gradient, Zn(OH) 4 2− ions tend to migrate from the zinc anode to the air cathode through the electrolyte.…”

A Review of the Use of GPEs in Zinc-Based Batteries. A Step Closer to Wearable Electronic Gadgets and Smart Textiles

“…Chaduang et al [282] used commercial Carbopol 940 (crosslinked PAA) to highlight the improvement of discharge/recharge performance on a flexible Zinc-air battery. Likewise, Wang et al [283] develop a separator based on a paper soaked in PAA/PVA solution to enhance the battery performance.…”