Work

Electronic Synergistic Effects on the Stability and Oxygen Evolution Reaction Efficiency of the Mesoporous LiMn2–xMxO4 (M = Mn, Fe, Co, Ni, and Cu) Electrodes

Year: 2024

Type: article

Abstract: Stable porous manganese oxide-based electrodes are essential for clean energy generation and storage because of their high natural abundance and health safety. This investigation focuses on mesoporous LiMn 2– x M x O 4 (where M is Fe, Co, Ni, and Cu and x is 0, 0.1, 0.3, 0.5, and 0.67) electrodes and thin/thick films. The mesoporous electrodes and films are fabricated by coating clear and homogeneous ethanol solutions of the salts (LiNO 3, [Mn(OH 2 ) 4 ](NO 3 ) 2, and [M(OH 2 ) x ](NO 3 ) 2 ) and surfactants (P123 and CTAB) and calcining at elevated temperature (denoted as F-LiMn 2– x M x O 4, G-LiMn 2– x M x O 4, and meso -LiMn 2– x M x O 4, respectively). The electrochemical properties, stability, and oxygen evolution reaction (OER) performance of the F/G-LiMn 2– x M x O 4 electrodes are investigated in alkaline media using a three electrode setup. The F-LiMn 1.33 M 0.67 O 4 electrodes (where M is Mn, Fe, Co, and Ni) exhibit low Tafel slopes of 60, 43, 44, and 32 mV/dec, respectively. While all the Mn-rich and F-LiMn 2– x Fe x O 4 electrodes degrade via Mn(VI) disproportionation reaction, the 33% Co electrode shows high stability during the OER. The nickel-based electrodes are stable with as little as 15% Ni and display excellent OER performance over 25% Ni, albeit undergoing a transformation that accumulates Ni(OH) 2 species on the electrode surface. Copper in the F-LiMn 2– x Cu x O 4 electrodes is homogeneous at low Cu percentages but forms a CuO phase above 15% Cu, undergoes degradation, and displays a weak OER performance. In short, Co and Ni stabilize the F-LiMn 1.33 Co 0.67 O 4 and F-LiMn 1.7 Ni 0.3 O 4 electrodes, which display excellent OER performance.

Source: Inorganic Chemistry

DOI: 10.1021/acs.inorgchem.4c03885

Authors: Irmak Karakaya Durukan, Ömer Dag

Institutions: Bilkent University, National Nanotechnology Research Center

Language: English

Topic: Electrocatalysts for Energy Conversion

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $4,500