Synthesis and electrochemical characterizations of spinel LiMn1.94MO4 (M = Mn0.06, Mg0.06, Si0.06, (Mg0.03Si0.03)) compounds as cathode materials for lithium-ion batteries

Zhao, Hongyuan; Liu, Xingquan; Cheng, Cai; Li, Qiang; Zhang, Zheng; Wu, Yue; Chen, Bing; Xiong, Weiqiang

doi:10.1016/j.jpowsour.2015.02.049

Cited by 51 publications

(27 citation statements)

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“…In addition, the synthetic method could have a significant influence on the electrochemical properties. So far, the LiMn 2 O 4 cathode materials have been obtained by a solid-state method [38,39], hydrothermal method [40,41], combustion method [31,42,43], co-precipitation method [44], sol-gel method [45,46,47], and so on. Among these methods, the sol-gel method is highly suitable to prepare the high-performance, doped LiMn 2 O 4 due to the following advantages: (1) the reactants are evenly mixed at the molecular level in the process of forming a gel; (2) uniform cation doping can be achieved due to the intimate mixing of chemical contents in a solution; and (3) the chemical reaction is carried out easily, because the diffusion of the components is on a nanometer scale, which requires relatively low synthetic temperature.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Cycling Stability through Erbium Doping of LiMn2O4 Cathode Material Synthesized by Sol-Gel Technique

et al. 2018

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In this work, LiMn2−xErxO4 (x ≤ 0.05) samples were obtained by sol-gel processing with erbium nitrate as the erbium source. XRD measurements showed that the Er-doping had no substantial impact on the crystalline structure of the sample. The optimal LiMn1.97Er0.03O4 sample exhibited an intrinsic spinel structure and a narrow particle size distribution. The introduction of Er3+ ions reduced the content of Mn3+ ions, which seemed to efficiently suppress the Jahn–Teller distortion. Moreover, the decreased lattice parameters suggested that a more stable spinel structure was obtained, because the Er3+ ions in a ErO6 octahedra have stronger bonding energy (615 kJ/mol) than that of the Mn3+ ions in a MnO6 octahedra (402 kJ/mol). The present results suggest that the excellent cycling life of the optimal LiMn1.97Er0.03O4 sample is because of the inhibition of the Jahn-Teller distortion and the improvement of the structural stability. When cycled at 0.5 C, the optimal LiMn1.97Er0.03O4 sample exhibited a high initial capacity of 130.2 mAh g−1 with an excellent retention of 95.2% after 100 cycles. More significantly, this sample showed 83.1 mAh g−1 at 10 C, while the undoped sample showed a much lower capacity. Additionally, when cycled at 55 °C, a satisfactory retention of 91.4% could be achieved at 0.5 C after 100 cycles with a first reversible capacity of 130.1 mAh g−1.

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Section: Introductionmentioning

confidence: 99%

Enhanced Cycling Stability through Erbium Doping of LiMn2O4 Cathode Material Synthesized by Sol-Gel Technique

et al. 2018

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“…As shown here, the characteristic peaks of all these samples match with that of LiMn 2 O 4 (JCPDS No. 35-0782), implying that the Cu-doping strategy have no material impact on the inherent structure of LiMn 2 O 4 [17,33], where lithium and manganese ions occupy the tetrahedral sites (8a) and octahedral sites (16d), respectively. According to the reported research result, the (220) characteristic peak may be observed if other cations occupied the tetrahedral sites [34].…”

Section: Resultsmentioning

confidence: 99%

“…However, this value increases to 158.1 Ω cm 2 with growth rate of 69.6%. Through the above analysis, it is concluded that replacing some trivalent manganese ions with copper ions can have a constructive role in decreasing the R 2 value and enhancing the diffusion of lithium ions [33,38,39]. …”

Section: Resultsmentioning

confidence: 99%

Enhanced Cycling Stability of LiCuxMn1.95−xSi0.05O4 Cathode Material Obtained by Solid-State Method

Zhao

Bai

et al. 2018

Materials

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The LiCuxMn1.95−xSi0.05O4 (x = 0, 0.02, 0.05, 0.08) samples have been obtained by a simple solid-state method. XRD and SEM characterization results indicate that the Cu-Si co-doped spinels retain the inherent structure of LiMn2O4 and possess uniform particle size distribution. Electrochemical tests show that the optimal Cu-doping amount produces an obvious improvement effect on the cycling stability of LiMn1.95Si0.05O4. When cycled at 0.5 C, the optimal LiCu0.05Mn1.90Si0.05O4 sample exhibits an initial capacity of 127.3 mAh g−1 with excellent retention of 95.7% after 200 cycles. Moreover, when the cycling rate climbs to 10 C, the LiCu0.05Mn1.90Si0.05O4 sample exhibits 82.3 mAh g−1 with satisfactory cycling performance. In particular, when cycled at 55 °C, this co-doped sample can show an outstanding retention of 94.0% after 100 cycles, whiles the LiMn1.95Si0.05O4 only exhibits low retention of 79.1%. Such impressive performance shows that the addition of copper ions in the Si-doped spinel effectively remedy the shortcomings of the single Si-doping strategy and the Cu-Si co-doped spinel can show excellent cycling stability.

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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%

“…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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Synthesis and electrochemical characterizations of spinel LiMn1.94MO4 (M = Mn0.06, Mg0.06, Si0.06, (Mg0.03Si0.03)) compounds as cathode materials for lithium-ion batteries

Cited by 51 publications

References 43 publications

Enhanced Cycling Stability through Erbium Doping of LiMn2O4 Cathode Material Synthesized by Sol-Gel Technique

Enhanced Cycling Stability through Erbium Doping of LiMn2O4 Cathode Material Synthesized by Sol-Gel Technique

Enhanced Cycling Stability of LiCuxMn1.95−xSi0.05O4 Cathode Material Obtained by Solid-State Method

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

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