{"title":"Gel polymer electrolytes containing SiO2 spheres with tuned sizes to increase rechargeability of quasi-solid-state Zn-air batteries","authors":"César Coello‒Mauléon, Alejandro Arredondo-Espínola, Lorena Álvarez‒Contreras, Minerva Guerra‒Balcázar, Noé Arjona","doi":"10.1016/j.electacta.2024.145265","DOIUrl":null,"url":null,"abstract":"Rechargeable zinc–air batteries (RZABs) with high energy densities and low costs have attracted tremendous interest for meeting the ever-growing demand for flexible and portable applications. In these batteries, the quasi-solid/solid-state electrolyte plays a critical role in the battery performance, such as the cycling performance rate and power output. In this study, porous poly (vinyl alcohol) (PVA) and poly (acrylic acid) (PAA) composite gel polymer electrolytes (GPEs) were modified by incorporating SiO<sub>2</sub> as a water retainer. For this reason, SiO<sub>2</sub> spheres of different sizes were synthesized by varying the temperature (5, 20, 60, and 80°C) and reaction time (2, 6, 18, and 24 h). According to the SEM micrographs, the average size ranged from 107 to 710 nm depending on the conditions. The porous PVA/PAA–SiO<sub>2</sub> GPEs obtained by selecting three SiO<sub>2</sub> sizes (107, 425, and 630 nm) exhibited higher water retention capability than the unmodified GPE. Among them, the GPE with SiO<sub>2</sub>-630 nm displayed the highest battery performance (1.46 V, 85 mW cm<sup>−2</sup> @ 0.8 V). This was achieved using CoMn<sub>2</sub>O<sub>4</sub> spinel as a bifunctional electrocatalyst, with a catalyst loading of 2 mg cm<sup>−2</sup>. The quasi-solid-state RZAB displayed twice the rechargeability of the RZAB assembled with Pt/C+IrO<sub>2</sub>/C (120 <em>vs</em>. 62 cycles). According to <em>post-mortem</em> tests, this can be related to the improved water retention, the decrease in the size of the formed Zn dendrites, and the stability of the bifunctional material. Thus, fine-tuning of the electrocatalyst/electrolyte interface strongly affects the rechargeability.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":5.5000,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Electrochimica Acta","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1016/j.electacta.2024.145265","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ELECTROCHEMISTRY","Score":null,"Total":0}
引用次数: 0
Abstract
Rechargeable zinc–air batteries (RZABs) with high energy densities and low costs have attracted tremendous interest for meeting the ever-growing demand for flexible and portable applications. In these batteries, the quasi-solid/solid-state electrolyte plays a critical role in the battery performance, such as the cycling performance rate and power output. In this study, porous poly (vinyl alcohol) (PVA) and poly (acrylic acid) (PAA) composite gel polymer electrolytes (GPEs) were modified by incorporating SiO2 as a water retainer. For this reason, SiO2 spheres of different sizes were synthesized by varying the temperature (5, 20, 60, and 80°C) and reaction time (2, 6, 18, and 24 h). According to the SEM micrographs, the average size ranged from 107 to 710 nm depending on the conditions. The porous PVA/PAA–SiO2 GPEs obtained by selecting three SiO2 sizes (107, 425, and 630 nm) exhibited higher water retention capability than the unmodified GPE. Among them, the GPE with SiO2-630 nm displayed the highest battery performance (1.46 V, 85 mW cm−2 @ 0.8 V). This was achieved using CoMn2O4 spinel as a bifunctional electrocatalyst, with a catalyst loading of 2 mg cm−2. The quasi-solid-state RZAB displayed twice the rechargeability of the RZAB assembled with Pt/C+IrO2/C (120 vs. 62 cycles). According to post-mortem tests, this can be related to the improved water retention, the decrease in the size of the formed Zn dendrites, and the stability of the bifunctional material. Thus, fine-tuning of the electrocatalyst/electrolyte interface strongly affects the rechargeability.
期刊介绍:
Electrochimica Acta is an international journal. It is intended for the publication of both original work and reviews in the field of electrochemistry. Electrochemistry should be interpreted to mean any of the research fields covered by the Divisions of the International Society of Electrochemistry listed below, as well as emerging scientific domains covered by ISE New Topics Committee.