Electrochemical In-Situ Conductivity Measurements for Thin Film of Li1-xMn2O4 Spinel

Nishizawa, Masatoyo; Ise, Tomoaki; Koshika, Hiromichi; Itoh, Takashi; Uchida, Isamu

doi:10.1021/cm990696z

Cited by 46 publications

(47 citation statements)

References 29 publications

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“…9d). In the equivalent circuit, R o , R s , R e , and Z w represent the ohmic resistance of the cell, the interfacial resistance of electrolyte and the cathode, the electronic conductivity and Warburg diffusion impedance, respectively [27,28]. Charge-transfer resistance (R ct ) cannot be observed at 3.0 V which is in accordance with the previous report [29].…”

Section: Electrochemical Performancesupporting

confidence: 88%

Improved elevated temperature performance of commercial LiMn2O4 coated with LiNi0.5Mn1.5O4

Qiu

Wang

et al. 2014

Electrochimica Acta

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Section: Electrochemical Performancesupporting

confidence: 88%

Improved elevated temperature performance of commercial LiMn2O4 coated with LiNi0.5Mn1.5O4

Qiu

Wang

et al. 2014

Electrochimica Acta

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“…11. The electronic resistances of the electrode materials in the charge process have the same change tendency with potentials, namely, R e first decrease and then increase with the increase of the electrode polarization potential in the charge process, in accordance with the experiment results obtained by Nishizawa et al [39]. Spinel Li 1−x Mn 2 O 4 is a mixed-valence (Mn 3+ /Mn 4+ ) compound and its electronic conduction takes place by electron-hopping between high-valence (Mn 4+ ) and low-valence (Mn 3+ ) cations [40,41].…”

Section: Analysis Of the Equivalent Circuit Of Eis In Initial Charge supporting

confidence: 90%

Comparison of different soft chemical routes synthesis of submicro-LiMn2O4 and their influence on its electrochemical properties

Cui

Bao

Zheng

et al. 2011

J Solid State Electrochem

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A comparative study of submicro-crystalline spinel LiMn 2 O 4 powders prepared by two different soft chemical routes such as hydrothermal and sol-gel methods is made. The dependence of the physicochemical properties of the spinel LiMn 2 O 4 powder has been extensively investigated by using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, cyclic voltammogram, charge-discharge test, and electrochemical impedance spectroscopy (EIS). The results show that the electrochemical performances of spinel LiMn 2 O 4 depend strongly upon the synthesis method. The LiMn 2 O 4 powder prepared by hydrothermal route has higher specific capacity and better cycling performance than the one synthesized from sol-gel method. The former has the max discharge capacity of 114.36 and 99.78 mAh g −1 at the 100th cycle, while the latter has the max discharge capacity of 98.67 and 60.25 mAh g −1 at the 100th cycle. The selected equivalent circuit can fit well the EIS results of synthesized LiMn 2 O 4 . For spinel LiMn 2 O 4 from sol-gel method and hydrothermal route in the first charge process R SEI remain almost invariable, R e and R ct first decreasing and then increasing with the increase of polarization potential.

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“…This is a factor of 25 higher than the in situ conductivity reported by Uchida et al for spinel films of Li x MnO 2 . 24,25 Second, the conductivity change for nanowires as a function of x is greater in absolute terms than seen previously for films. Finally, we observe a strong dependence of σ on the nanowire width at constant nanowire height: Increasing the nanowire width reduces σ for all values of x while also dramatically reducing the degree to which σ is modulated by x.…”

Section: ■ Introductionmentioning

confidence: 67%

In Situ Electrical Conductivity of Li_xMnO₂ Nanowires as a Function of x and Size

Le¹,

Liu²,

Wang

et al. 2015

Chem. Mater.

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Manganese oxide, MnO 2 , excels as a hybrid electrical energy storage material: The manganese centers in MnO 2 are capable of undergoing a reduction from 4+ to 3+ balanced by the intercalation of lithium ions to form Li x MnO 2 while its conductive surfaces simultaneously store energy as an electrical double layer capacitor. The highest capacitance and power performance for MnO 2 has been obtained for ensembles of nanowires that are 200 nm or less in width and many microns in length. Typically such MnO 2 nanowires are attached to a current collector at just one end, and electrical conductivity of the nanowire is therefore required in order to maintain a consistent redox and charge state along its axis. The electrical conductance of the nanowire therefore plays a very important role, and yet this parameter has been measured in few previous studies. In this work, we directly measure the electrical conductance of δ-MnO 2 nanowires in situ in 1 M LiClO 4 , acetonitrile as a function of the equilibrium Li content for nanowires with varying lateral dimensions. This measurement is accomplished using arrays of 200 MnO 2 nanowires that are 40−60 nm in height and 275−870 nm in width and which span a 10 μm gap between two gold contacts. Nanowires of fully oxidized MnO 2 are first prepared at +0.60 V vs MSE in acetonitrile. As the equilibrium electrode potential is decreased from 0.60 V to −0.80 V and lithium is intercalated, the electrical conductivity of MnO 2 nanowires increases by up to 1 order of magnitude. The measured change in conductivity is dependent on the equilibrium potential, which in turn is related to the Li content, and also depends on the width of nanowires. After doping at −0.80 V vs MSE, the conductivity increases by 30% for a 870 nm wide nanowire array and 880% for a 275 nm wide nanowire array. TEM investigations implicate the nanowire porosity in this difference.

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Electrochemical In-Situ Conductivity Measurements for Thin Film of Li_1-xMn₂O₄ Spinel

Cited by 46 publications

References 29 publications

Improved elevated temperature performance of commercial LiMn2O4 coated with LiNi0.5Mn1.5O4

Improved elevated temperature performance of commercial LiMn2O4 coated with LiNi0.5Mn1.5O4

Comparison of different soft chemical routes synthesis of submicro-LiMn2O4 and their influence on its electrochemical properties

In Situ Electrical Conductivity of Li_xMnO₂ Nanowires as a Function of x and Size

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Electrochemical In-Situ Conductivity Measurements for Thin Film of Li1-xMn2O4 Spinel

Cited by 46 publications

References 29 publications

Improved elevated temperature performance of commercial LiMn2O4 coated with LiNi0.5Mn1.5O4

Improved elevated temperature performance of commercial LiMn2O4 coated with LiNi0.5Mn1.5O4

Comparison of different soft chemical routes synthesis of submicro-LiMn2O4 and their influence on its electrochemical properties

In Situ Electrical Conductivity of LixMnO2 Nanowires as a Function of x and Size

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Electrochemical In-Situ Conductivity Measurements for Thin Film of Li_1-xMn₂O₄ Spinel

In Situ Electrical Conductivity of Li_xMnO₂ Nanowires as a Function of x and Size