Crystal structure, phase relations and electrochemical properties of monoclinic Li2MnSiO4

Politaev, V.V.; Петренко, А.А.; Nalbandyan, V. B.; Medvedev, B.S.; Shvetsova, Ekaterina

doi:10.1016/j.jssc.2007.01.001

Cited by 161 publications

(143 citation statements)

References 16 publications

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“…The reason for observed differences in QS values is not fully understood, however we presume this difference can be ascribed to the different polymorph used in our experiment as it was used by Nyten. It is worth to mention that the existence of different polymorphs in Li 2 FeSiO 4 was not proven yet, however the above opinion is based on the work on Li 2 MnSiO 4 and Li 2 CoSiO 4 [2,3,12,20]. Based on our in-situ Mössbauer experiment we agree with a conclusion given by Nyten [7], that local environment of iron observed with Mössbauer spectroscopy is very similar before and after "phase transition" reflected as a shift of potential from 3.1 to 2.8 V. At the end of Mössbauer part we need to emphasize that Mössbauer parameters of the magnetic phase remain very similar during the oxidation/reduction process in all fitted spectra.…”

Section: Xrd and Mössbauer Analysismentioning

confidence: 99%

In-situ XAS study on Li2MnSiO4 and Li2FeSiO4 cathode materials

Dominko

Arčon

Kodre

et al. 2009

Journal of Power Sources

124

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Section: Xrd and Mössbauer Analysismentioning

confidence: 99%

In-situ XAS study on Li2MnSiO4 and Li2FeSiO4 cathode materials

Dominko

Arčon

Kodre

et al. 2009

Journal of Power Sources

124

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“…Thus, LM2 with 20 wt % of acetylene black shows a superior electrochemical stability and a higher rate capability as compared to those reported so far. [15][16][17][18][19] Because the electrical conductivity of Li 2 MnSiO 4 is very low, almost in the insulator range, it is expected that a large impedance would develop at the cathode-electrolyte interface that would hinder the electrochemical intercalation of Li during charge-discharge. The impedance spectra of the cells LM0 and LM2 have been recorded at various stages, before any charge-discharge and during cycling after 10 and 20 cycles.…”

Section: A678mentioning

confidence: 99%

Improved Electrochemical Performance of Li[sub 2]MnSiO[sub 4]/C Composite Synthesized by Combustion Technique

Ghosh

Mahanty

Basu

2009

J. Electrochem. Soc.

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Li 2 MnSiO 4 cathode powders were synthesized by a simple combustion technique using citric acid as a chelating agent. The as-synthesized powder was ballmilled with acetylene black ͑0-20 wt %͒ and heated at 700°C in argon atmosphere to form a Li 2 MnSiO 4 /C composite. X-ray powder diffraction indicated the formation of Li 2 MnSiO 4 possessing an orthorhombic crystal structure along with manganese oxide as a minor impurity phase. Field-emission-scanning electron microscopy showed that pristine Li 2 MnSiO 4 consists of large agglomerates of ϳ500 to 800 nm. The addition of acetylene black resulted in a drastic change in morphology for Li 2 MnSiO 4 /C composites consisting of uniform grains of ϳ50 nm. The electrochemical discharge capacity as well as the rate capability of Li 2 MnSiO 4 also improved dramatically with an increasing amount of conducting carbon ͑acetylene black͒ in the matrix, and a value as high as 164 mAh g −1 was obtained at a current density of 0.01 mA/cm 2 . Impedance spectroscopy showed that the addition of acetylene black decreases the charge-transfer impedance and checks the growth of cell impedance during cycling. Cyclic voltammetry showed two oxidation/reduction couples at 3.6/2.9 and 4.5/4.3 V with good reversibility. Rechargeable lithium-ion batteries are the most advanced battery systems among the contemporary energy storage technologies in terms of accessible energy density, reversibility, and cycle life. It is presently used in virtually all electronic devices and is projected as the power source for electric vehicles. However, the conventional cathode materials, namely, LiCoO 2 , LiMn 2 O 4 , and LiFePO 4 , suffer from one or more problems related to structural stability, rate capability, energy density, etc.

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“…4,7,8 Two of the three known polymorphs of Li 2 MnSiO 4 are orthorhombic (Pmnb and Pmn2 1 ), whereas the third is monoclinic (P2 1 /n). 8 Ab initio density-functional theory (DFT) calculations have shown that both orthorhombic structures are more stable than the monoclinic one. 9 As shown by Sirisopanaporn et al 10 for Li 2 FeSiO 4 and by Lyness et al 11 for Li 2 CoSiO 4 , the crystal structure is known to have an influence on the electrochemical behavior.…”

Section: Introductionmentioning

confidence: 99%

Novel Pn Polymorph for Li₂MnSiO₄ and Its Electrochemical Activity As a Cathode Material in Li-Ion Batteries

et al. 2011

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We report on the synthesis and characterization of a new metastable polymorph of Li 2 MnSiO 4 adopting the Pn space group, prepared by ion-exchange from Na 2 MnSiO 4 . Density-functional theory methods were used to predict the lattice parameters and atom positions of the new polymorph material and those of Na 2 MnSiO 4 and LiNaMnSiO 4 , allowing their identification by X-ray diffraction profiles, as well as the comparison of the measured and calculated cell parameters. The electrochemical activity of this new polymorph as a cathode material for lithium ion batteries was evaluated in coin cells and compared to that of the thermodynamically stable Pmn2 1 polymorph of Li 2 MnSiO 4 , as well as LiNaMnSiO 4 and Na 2 MnSiO 4 . Carbon coating, very vital to the electrochemical activity of the material, was added in situ to the material before ion-exchange because the metastable polymorph converts to the stable polymorph above 370°C, as confirmed by differential scanning calorimetry scans. Both Li 2 MnSiO 4 polymorphs display similar charge−discharge curves, except for a marginally lower lithium extraction voltage during the first charge of the Pn structure that may be due to the presence of sodium ion impurities. A discharge capacity of 110 mA h g −1 is initially observed for both Li 2 MnSiO 4 polymorphs and both exhibit similar capacity fades. LiNaMnSiO 4 , however, yields a stable capacity of 45 mA h g −1 , whereas Na 2 MnSiO 4 yields an initial capacity of 20 mAh g −1 , increasing to 60 mAh g −1 with cycling. KEYWORDS: lithium manganese silicate, polymorphism, Li-ion battery

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Crystal structure, phase relations and electrochemical properties of monoclinic Li2MnSiO4

Cited by 161 publications

References 16 publications

In-situ XAS study on Li2MnSiO4 and Li2FeSiO4 cathode materials

In-situ XAS study on Li2MnSiO4 and Li2FeSiO4 cathode materials

Improved Electrochemical Performance of Li[sub 2]MnSiO[sub 4]/C Composite Synthesized by Combustion Technique

Novel Pn Polymorph for Li₂MnSiO₄ and Its Electrochemical Activity As a Cathode Material in Li-Ion Batteries

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Crystal structure, phase relations and electrochemical properties of monoclinic Li2MnSiO4

Cited by 161 publications

References 16 publications

In-situ XAS study on Li2MnSiO4 and Li2FeSiO4 cathode materials

In-situ XAS study on Li2MnSiO4 and Li2FeSiO4 cathode materials

Improved Electrochemical Performance of Li[sub 2]MnSiO[sub 4]/C Composite Synthesized by Combustion Technique

Novel Pn Polymorph for Li2MnSiO4 and Its Electrochemical Activity As a Cathode Material in Li-Ion Batteries

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Novel Pn Polymorph for Li₂MnSiO₄ and Its Electrochemical Activity As a Cathode Material in Li-Ion Batteries