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HỘI THẢO QUỐC TẾ ATiGB LẦN THỨ CHÍN - The 9 ATiGB 2024 161

reactions within the aqueous electrolyte generate Currently, there is extensive research on various
hydrogen gas (HER), resulting in non-uniform contact materials for use as cathode electrodes in zinc-ion
surfaces between the battery layers, which increases batteries, including different tunnel-structured
internal resistance and reduces battery performance. manganese oxides, vanadium oxides with diverse
Thirdly, these side reactions cause the corrosion of the crystalline structures, and transition metal sulfides.
zinc anode, leading to uneven zinc deposition and the Vanadium oxides offer stable capacity and excellent
formation of zinc dendrites. The growth of these battery lifespan, but their high toxicity may limit their
dendrites can puncture the separator, causing short applications. Manganese oxide materials are up-and-
circuits within the battery. To address these drawbacks, coming due to their high electrochemical window,
researchers have focused on the anode electrode: cost-effectiveness, non-toxic nature, and abundant
modifying it and using additives to coat the surface of resources, making them highly suitable for
the zinc metal electrode. Additionally, researchers are commercialization. This study focuses on the
concentrating on incorporating additives into the synthesis of β-MnO2 nanorod material using the
aqueous electrolyte to minimize the side reactions that hydrothermal method at 140°C for 12 hours for
produce H2 gas [6], [7], [8]. application as the positive electrode in pouch-type
aqueous zinc-ion batteries.

Fig. 1. Illustrative image of the structure ofa pouch cell system using the synthesized MnO 2 material
as the cathode in an aqueous Zn-ion battery
2. EXPERIMENT 3MnSO + 4 2KMnO + 2H O
2.1. Material preparation and characterization 4 2 (1)
→ 5MnO + K SO + 2H SO
β-MnO 2 was prepared via a one-step hydrothermal 2 2 4 2 4
method. Initially, 0.3 M (mol L-1) of MnSO4 (Xilong- 2.2. Preparation of pouch cell
China, purity 99%) and 0.2 M (mol L-1) of KMnO4 MnO 2 electrode. A blend consisting of MnO2, Super
(Xilong-China, purity 99%) were each dissolved P(TOB-China, 99% purity), and Sodium Carboxymethyl
separately in 25 mL of deionized water with vigorous Cellulose (CMC) binder (Yulong-China, 99% purity)
stirring for 30 minutes. The two solutions were then was created in a ratio of 7:2:1. Mix the three components
combined and stirred for an additional 30 minutes. The in a 7:2:1 ratio (140 mg MnO2, 40 mg Super P, 20 mg
prepared mixture was moved to a 150 mL Teflon-coated CMC) using an agate mortar and pestle. Gradually add
autoclave and heated at 140°C for 12 hours. Once cooled distilled water while stirring for 1 hour. Then, coat the
to ambient temperature, the sample was subjected to suspension onto a carbon cloth using a doctor's blade.
filtration and rinsed multiple times with distilled water, Dry the coated cloth at 50°C for 2 hours to obtain the
acetone (Xilong-China, 99% purity), and absolute MnO 2 electrode. The mass loading of the β-MnO 2
ethanol (Xilong-China, 99% purity) to eliminate any electrode was about 1 mg/cm .
2
remaining salts and contaminants. Finally, the product
was dried at 60°C overnight to obtain β-MnO 2 powder. Aqueous electrolyte: using electrolyte solution of 2M
The overall reaction can be described as follows: ZnSO4 and 0.2 M MnSO4.

ISBN: 978-604-80-9779-0