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KR-20260063496-A - AIR ELECTRODE AND METAL-AIR BATTERY INCLUDING SAME

KR20260063496AKR 20260063496 AKR20260063496 AKR 20260063496AKR-20260063496-A

Abstract

The present invention relates to an air electrode capable of improving electrochemical stability by minimizing interference between oxygen evolution and reduction reactions by including a carbon fiber layer coated with an oxygen evolution reaction catalyst and a carbon fiber layer coated with an oxygen reduction reaction catalyst, a metal-air battery including the same, and a method for manufacturing the same.

Inventors

  • 안성훈

Assignees

  • 조선대학교산학협력단

Dates

Publication Date
20260507
Application Date
20241030

Claims (11)

  1. An air electrode for a metal-air battery comprising a carbon fiber layer coated with an oxygen evolution reaction catalyst and a carbon fiber layer coated with an oxygen reduction reaction catalyst.
  2. An air electrode for a metal-air battery according to claim 1, wherein the carbonized fiber is formed by carbonizing cotton.
  3. A metal-air battery comprising the air electrode of claim 1 or 2.
  4. A metal-air battery according to claim 3, comprising a sequentially stacked cathode, an intermediate layer, a solid electrolyte, and the air electrode.
  5. A metal-air battery according to claim 4, wherein the negative electrode is made of zinc, magnesium, lithium, or iron.
  6. A metal-air battery according to claim 4, wherein the intermediate layer is a carbon fiber coated with a metal affinity to the negative electrode.
  7. A metal-air battery according to claim 6, wherein the negative electrode is made of zinc and the metal affinity to the negative electrode is copper.
  8. An electric device comprising the metal-air battery of claim 3.
  9. A method for manufacturing an air electrode for a metal-air battery, comprising the steps of: carbonizing cotton to obtain carbonized fibers; and coating the carbonized fibers with an oxygen evolution reaction catalyst or an oxygen reduction reaction catalyst to obtain a carbonized fiber layer coated with an oxygen evolution reaction catalyst or a carbonized fiber layer coated with an oxygen reduction reaction catalyst.
  10. A method for manufacturing a metal-air battery comprising the step of stacking a cathode, an intermediate layer, a solid electrolyte, and an air electrode manufactured by the method of claim 9.
  11. A method for manufacturing a metal-air battery according to claim 10, further comprising the steps of: carbonizing a cotton to form a carbon fiber layer; and coating a metal having an affinity with the metal material of the cathode on the carbon fiber layer to produce the intermediate layer.

Description

Air electrode and metal-air battery including the same The present invention relates to an air electrode and a metal-air battery including the same. Recently, the development of alternative energy storage platforms such as ZAB has been accelerated due to the risk of explosion in lithium-ion batteries and the rapid rise in the price of electrode materials. In particular, ZAB is attracting attention as a power source for wearable devices because it uses a stable aqueous electrolyte, eliminates the risk of explosion, has a relatively high energy density (~1370 Wh kg⁻¹ , excluding oxygen), and has biocompatibility with solid gel electrolytes. Although solid-state ZABs with ampere-scale discharge capacities have been reported in previous studies, such research is rare and requires a high level of technical expertise. Major obstacles to commercialization exist, such as low discharge capacities and limited lifespans of ZABs due to dendrite formation and corrosion issues of the zinc anode. In particular, the problem of zinc dendrite formation occurring in strong alkaline electrolytes limits discharge capacity, while the low catalytic activity and reaction rate of the air electrode result in low Coulomb efficiency. Therefore, a strategy to simultaneously address the problems of both the anode and the cathode is essential to achieve ampere-scale discharge capacities in solid-state ZABs. Various strategies have been proposed to suppress dendrite growth on zinc anodes. Representative methods include modifying the electrolyte or additives, using three-dimensional structured host materials, and introducing zinc-friendly interlayers. In particular, the method of introducing zinc-friendly interlayers is simple in process and advantageous for mass production; furthermore, the interlayer prevents zinc dendrite formation and promotes uniform zinc plating, which can significantly improve the performance of the anode. However, mass-producing these interlayers as ultrathin films while maintaining their mechanical strength remains a challenge. Furthermore, the design of the air electrode plays a crucial role in enhancing ZAB performance. Recent studies have proposed functionally separated asymmetric air electrodes to promote the oxygen reduction (ORR) and oxygen evolution (OER) reactions. This asymmetric electrode design has significantly improved the practical performance of ZAB by enhancing catalytic activity and reaction rates. However, such structures are complex and costly, posing challenges for commercial expansion. This project (result) is the result of the Local Government-University Cooperation-based Regional Innovation Project conducted in 2024 with funding from the Ministry of Education and support from the National Research Foundation of Korea (Project Management No.: 2021RIS-002). Fig. 1. (a) Schematic diagram of a large-area (36 cm² or larger) anode laminated pouch battery. It includes an amphiphilic bilayer air cathode, a copper-induced zinc cathode, a zinc-affinity copper interlayer, a gel electrolyte, a hydrophilic NiFe(OH) ₂ layer, and a hydrophobic FeNC layer. (b) A photograph showing the process of producing flexible carbon fiber (CF) by unwinding a carbon roll (CR). (c) An image showing the CF layer separation by a simple finger rub, demonstrating ease of handling and processing. (d) A cross-sectional view of the bilayer CF electrode, showing the hydrophilic NiFe(OH) ₂ OER layer and the hydrophobic FeNC ORR layer. (e) A detailed image of the bilayer CF electrode, showing the inner hydrophobic ORR side and the outer hydrophilic OER side. Fig. 2. (a) SEM image of carbon fiber (CF) showing fibrous structure and high porosity. (b) TEM image of the FeNC layer showing a thin, flexible carbon material with uniformly distributed FeNC particles. (c) HR-TEM image of the FeNC layer showing Fe-NC sites dispersed at the atomic level (white circles). (d) Elemental mapping of the FeNC layer showing the distribution of C, N, and Fe elements. (e) Cross-sectional SEM image of a NiFe(OH) 2 layer on the CF showing a uniform coating and a thickness of approximately 100 nm. (f) TEM image of the NiFe(OH) 2 layer showing a porous matrix in the form of nanosheets. (g) HR-TEM image of NiFe(OH) 2 showing a lattice spacing of 0.242 nm. (h) Elemental mapping of the NiFe(OH) 2 layer showing the distribution of Ni, Fe, and C elements. (i) Cross-sectional SEM image of the double-layer CF electrode showing the hydrophilic NiFe(OH) 2 OER side and the hydrophobic FeNC ORR side. (j) Elemental mapping of the double-layer structure showing the distribution of Ni, Fe, C, and N elements within the composite material. (k) Time-lapse image (within 60 ms) showing the rapid absorption of a water droplet on the surface of the hydrophilic NiFe(OH) 2 layer. (l) Thin film XRD patterns of the s-CF-FeNC, s-CF-NiFe, and bi-CF-F/N electrodes. (m) XPS irradiation spectra of the hydrophilic OER side and the hydrophobic ORR side of the double-layer CF electrode.