Structure and surface chemistry of Al2O3 coated LiMn2O4 nanostructured electrodes with improved lifetime

Self‐discharge caused by hydrogen evolution reaction (HER) coinciding with corrosion of the zinc anode is a major drawback of printed zinc‐air batteries. Thus, this work aims at suppressing self‐discharge of flexible printed zinc‐air batteries by coating thin layer of aluminum oxide (Al2O3) onto the surface of zinc particles. The Al2O3 coating layer was directly synthesized onto the zinc particles by a low‐cost and facile sol–gel method. The Al2O3 coating effectively mitigated HER of the zinc particles, and delayed the corrosion of the zinc anode. Further, the effects of the thickness of Al2O3 layer on corrosion behavior of the zinc anode in 9 M potassium hydroxide as well as performance of the batteries were investigated. With a proper thickness of Al2O3 coating, corrosion of the battery was considerably suppressed without sacrificing the battery performance. (a) Photographic image of the fabricated battery, (b) transmission electron microscopic image of zinc particle coated with Al2O3.

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“…Further, ALD of

{Al}_{2} O_{3}

{LiMn}_{2} O_{4}

/carbon electrodes was implemented in LiBs (). It was found that besides acting as a physical barrier between the electrolyte and the electrode, the

{Al}_{2} O_{3}

coating exhibits a relatively good ionic conductivity and prevents the significant increase in polarization resistance.…”

Section: Introductionmentioning

confidence: 99%

Suppression of zinc anode corrosion for printed flexible zinc‐air battery

Wongrujipairoj

Poolnapol

Arpornwichanop

et al. 2016

Physica Status Solidi (b)

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“…The procedure to determine the average manganese valence consisted in directly transferring [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] . In this case, the blank was a solution containing only NaCH 3 COO and 1,10-phenanthroline, obtained by adding 10 mL of aqueous 10% (m/m) NaCH 3 COO and 0.1% (m/m) 1,10-phenanthroline solutions to a 50 mL volumetric flask and completing its volume with deionized water.…”

Section: Methodsmentioning

confidence: 99%

“…7 This capacity loss is usually correlated with the (i) Jahn-Teller effect, which occurs mainly during charge-discharge at 3 V vs. Li/Li + , 3,8 (ii) manganese dissolution caused by the disproportionation reaction 2Mn 3+ (s) → Mn 4+ (s) + Mn 2+ (slv), 3,9 and (iii) instability of the spinel structure at the end of the charging process due to oxygen loss. 3 Different experimental strategies have been employed to minimize these possible problems: change of precursors and synthesis conditions, 10,11 change of size and morphology of the spinel particles, 12,13 coating of the spinel particles to prevent manganese dissolution, [14][15][16] trapping of the Mn cation, 17 and doping of the spinel Li x Mn 2 O 4 with different cations and anions. 3,7,18 This last strategy is one of the most employed and cited in the current literature.…”

Section: Introductionmentioning

confidence: 99%

A New, Friendlier Methodology to Determine the Average Manganese Valence in LixMn2O4 Spinels Using Atomic Absorption Spectrometry and Molecular Absorption Spectrophotometry

Silva¹,

Silva²,

Biaggio³

et al. 2017

J. Braz. Chem. Soc.

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An alternative, friendlier methodology for the determination of the average manganese valence (ν) of manganese oxides (mainly pure and doped spinels) is presented. This methodology is based on the facile determination of the concentration of Mn 2+ and Fe 2+ ions by atomic absorption spectrometry (AAS) and molecular absorption spectrophotometry (MAS), respectively. Prior to this determination, the manganese oxides are reacted with an acidic solution containing Fe 2+ ions, when all Mn ν+ ions are reduced to Mn 2+. Then, the concentration of Mn 2+ ions is obtained directly by AAS, whereas that of Fe 2+ ions is obtained by MAS after their complexation with o-phenanthroline. Using this methodology, the obtained mean (n = 3) ν values for the stoichiometric oxides Mn 2 O 3 and Mn 3 O 4 are 2.98 ± 0.01 and 2.66 ± 0.01, respectively; their precision is a clear evidence of the suitability of the here-proposed methodology. Additionally, a precise mean ν value (3.46 ± 0.01; n = 3) is also obtained for the spinel Li 1.05 Mn 2 O 4 , whereas a higher ν value (3.52 and 3.53; n = 2) is obtained for the doped spinel Li 1.05 Mn 1.98 Al 0.02 O 3.98 S 0.02 , evidencing that effective doping has been indeed attained. This novel methodology is easily applicable for Mn oxides in electrode materials of many energy storage devices. Keywords IntroductionIn the last decade, the popularization of portable electronic devices has increased, leading to a growing demand for lithium ion batteries (LIBs). In this scenario, some oxides have been targeted for studying and testing as cathode materials in LIBs; the spinel lithium manganese oxide (Li x Mn 2 O 4 ) is one of these oxides.1,2 The use of this spinel is favored by factors such as the manganese abundance, non-toxicity, and low cost, as well as the possibility of insertion of two lithium ions per formula unit.3 When 0 ≤ x ≤ 1, Li 3 Therefore, the average manganese valence of doped spinels is a useful parameter because it can provide information on their effective doping and structural changes.As far as we could ascertain, the most common approach to determine the average manganese valence of manganese oxides has been the Vetter and Jaeger's method, 33 employs an acid solution of potassium iodide to reduce all Mn ions in the manganese oxides to Mn 2+ ions. In this process, iodine is formed and quantified by titration with a sodium thiosulfate solution, while Mn 2+ ions are determined by titration with an EDTA solution. Titration of iodine was also proposed by Licci et al. 34 to determine the average manganese valence in Mn-La complexes. Firstly, after the Mn-La complex is dissolved in dilute H 2 SO 4 , the Mn ions are oxidized to permanganate ions by adding an excess of solid bismuthate, followed by the addition of an iodide solution (also in excess) that converts all permanganate ions into Mn 2+ ions, yielding iodine. In a parallel step, the Mn-La complex is reacted directly with an iodide solution, also yielding iodine. In both cases, the iodine is amperometrically titrated with a thio...

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“…To solve such problems, nano-sized LMO are prepared to enhance the Li + diffusion rate and improve structural stability, such as solvothermal [20], sol-gel [21], mechanical-chemical [22], and microwave sintering [23]. On the other hand, introducing modifications such as doping [24][25][26] and surface coating [27][28][29] is also quite universal. These measures are capable to optimize the crystal structure stability and suppress the dissolution of Mn 2+ [30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Facile One-Step Dynamic Hydrothermal Synthesis of Spinel LiMn2O4/Carbon Nanotubes Composite as Cathode Material for Lithium-Ion Batteries

Shen

Liu

et al. 2019

Materials

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Nano-sized spinel LiMn2O4/carbon nanotubes (LMO/CNTs) composite is facilely synthesized via a one-step dynamic hydrothermal approach. The characterizations and electrochemical measurements reveal that LiMn2O4 particles with narrow size distribution are well dispersed with CNTs in the composite. The LMO/CNTs nanocomposite with 5 wt % CNTs displays a high specific discharge capacity of 114 mAh g−1 at 1C rate, and the retention rate after 180 cycles at room temperature reaches 94.5% in the potential window of 3.3 to 4.3 V vs. Li/Li+. Furthermore, the electrochemical performance of the composite with 5 wt % CNTs at elevated temperature (55 °C) is also impressive, 90% discharging capacity could be maintained after 100 cycles at 1C. Such excellent electrochemical performance of the final product is attributed to the content of CNTs added in the hydrothermal process and small particle size inherited from pretreated MnO2 precursor.

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Structure and surface chemistry of Al2O3 coated LiMn2O4 nanostructured electrodes with improved lifetime

Cited by 97 publications

References 41 publications

Suppression of zinc anode corrosion for printed flexible zinc‐air battery

Suppression of zinc anode corrosion for printed flexible zinc‐air battery

A New, Friendlier Methodology to Determine the Average Manganese Valence in LixMn2O4 Spinels Using Atomic Absorption Spectrometry and Molecular Absorption Spectrophotometry

Facile One-Step Dynamic Hydrothermal Synthesis of Spinel LiMn2O4/Carbon Nanotubes Composite as Cathode Material for Lithium-Ion Batteries

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