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Updated: Aug 15, 2025

Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of ManganeseII Acetylacetonate
Published on: June 18, 2020
Valence Engineering Enhancing NH4 + Storage Capacity of Manganese Oxides
Tzu-Hao Lu1, Chenghui Zeng2, Haozhe Zhang1
1MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-carbon Chem & Energy Conservation of Guangdong Province, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, P. R. China.
Abstract:
Ammonium ions (NH4 + ), as non-metallic charge carriers, are attracting attention in aqueous batteries due to its low molar mass, element sufficiency, and non-toxicity. However, the host materials for NH4 + storage are still limited. Herein, an oxygen defects-rich manganese oxide (MnO2-x ) for NH4 + storage are reported. The oxygen defects can endow the MnO2-x sample with improved electric conductivity and low interface activation energy. The electrochemical reaction mechanism is also verified by using ex situ X-ray photoelectron spectroscopy (XPS) and fourier transform infrared spectroscopy (FT-IR), demonstrating the insertion and extraction of NH4 + in the MnO2-x by formation/breaking of a hydrogen bond. As a result, MnO2-x delivers a high capacity of 109.9 mAh g-1 at the current density of 0.5 A g-1 and retention of 24 mAh g-1 after 1000 cycles at the current density of 4 A g-1 , outperforming the pristine MnO2 sample.
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