The origin of electrochemical activity in Li2MnO3

Robertson, Alastair D.; Bruce, Peter G.

doi:10.1039/b207945c

Cited by 195 publications

(178 citation statements)

References 18 publications

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“…These materials contain Ni in the formal oxidation state of +3 rather than +2 as in the previous reports of anomalously high capacity materials. The discharge capacities obtained, as high as 240 mAh g −1 , were much greater than expected for 1:1 solid solutions of Li 2 MnO 3 -LiNi 1−x Co x O 2 .H o w e v e r ,e v e nf o r Li 2 MnO 3 it has been shown that charging to voltages greater than 4.3-4.4 V induces an unexpected reversible capacity [6].…”

Section: Introductionmentioning

confidence: 94%

Effects of synthesis on electrochemical, structural and physical properties of solution phases of Li2MnO3–LiNi1−xCoxO2

Whitfield

Niketic

Davidson

2005

Journal of Power Sources

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Section: Introductionmentioning

confidence: 94%

Effects of synthesis on electrochemical, structural and physical properties of solution phases of Li2MnO3–LiNi1−xCoxO2

Whitfield

Niketic

Davidson

2005

Journal of Power Sources

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“…Nevertheless, several publications have appeared with different procedures for activation of Li 2 MnO 3 and with varying capacity values. [5][6][7][8][9][10][11][12][13][14] The initial discharge capacity values are generally high for the activated phases of Li 2 MnO 3 , but cycling instability is observed in all reports. In order to enhance the cycling stability, composites of Li 2 MnO 3 with other layered lithiated transition metal oxides such as LiCoO 2 are studied.…”

mentioning

confidence: 99%

Composite of Li-Rich Mn, Ni and Fe Oxides as Positive Electrode Materials for Li-Ion Battery

Penki

Duraisamy

Kishore

et al. 2016

J. Electrochem. Soc.

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A porous layered composite of Li 2 MnO 3 and LiMn 1/3 Ni 1/3 Fe 1/3 O 2 (composition: Li 1.2 Mn 0.53 Ni 0.13 Fe 0.13 O 2 ) is prepared by reverse microemulsion method employing tri-block co-polymer, F068 as a soft-polymer template. The Co-free composite is studied as a cathode material for Li-ion battery. Several samples are prepared by heating the precursor in the temperature range between 500 and 900 • C. The N 2 adsorption/desorption studies reveal that the product samples possess mesoporosity with broadly distributed pores around 15-50 nm diameter. Pore volume and surface area decrease by increasing the temperature of preparation. Charge-discharge, cycling and rate capability are investigated. The discharge capacity of the sample prepared at 900 • C is about 170 mAh g −1 at a specific current of 25 mA g −1 with a good cycling stability. A value of 140 mAh g −1 is obtained at the end of 50 charge-discharge cycles. Discharge capacity of 91 mAh g −1 is obtained at a specific current of 206 mA g −1 . A high rate capacity of the composite is attributed to its porous nature. Research activities on lithium-ion batteries have increased in the recent past because of their attractive energy density. [1][2][3] In an extended range of applications, they are successful in small sizes at present and anticipated to be useful in large sizes for applications such as electric vehicles. Although the energy density of the present Li-ion batteries is the greatest among rechargeable batteries, future requirements such as electric vehicle applications require still greater energy density. The next generation Li-ion batteries, thus, need novel electrode materials which can provide greater discharge capacity than the present materials. Compounds with a high atomic ratio of extractable lithium to transition metal are expected to provide high discharge capacity values. Li 2 MnO 3 belongs to this category of materials.4 Li 2 MnO 3 is a layered oxide similar to LiCoO 2 and its formula can also be presented as Li (Li 0.33 was reported at a specific current of 30 mA g −1 in the potential range between 1.5 and 4.8 V. 33,34 In addition to the high discharge capacity, an electrode material needs to possess high rate capability for the purpose of fast charge or/and discharge. Porous materials are expected to possess high rate capability because the electrolyte can creep into particles and enhance the contact area. 35 As a result, the material can withstand an enhanced specific current during charge-discharge cycling. Furthermore, the electrode material can tolerate volume expansion and contraction that may occur during charge-discharge processes. To the best of authors' knowledge, there are only few reports available on the synthesis of porous composites of Li 2 MnO 3 . A porous composite of Li 2 MnO 3 with nanoplate morphology was prepared via colloidal crystal template of poly(methyl methacrylate) beads. The porous composite was better in electrochemical properties in relation to the nonporous composite. 36,37 Investigations on high capa...

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“…9). The unmarked voltage plateau is a characteristic of discharge process of Li 2 MnO 3 materials (Robertson and Bruce, 2002;Yue et al, 2008;Huang et al, 2009). Note that extending the voltage cutoff to 2.0 V resulted in higher capacity (157.5, 168.3 and 121.2 mAh g −1 for samples annealed at 550, 650 and 750°C); however, the capacities decayed more quickly.…”

Section: Resultsmentioning

confidence: 94%

Preparation of LiCoMnO<sub>4</sub> Assisted by Hydrothermal Approach and its Electrochemical Performance

You¹,

Huang²,

Lin³

et al. 2016

American Journal of Engineering and Applied Sciences

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LiCoMnO 4 materials have been synthesized via a hydrothermal approach followed by a post-annealing process. Pure phase of LiCoMnO 4 is unable to form under hydrothermal conditions; however, high quality of pure LiCoMnO 4 was achieved after annealing the hydrothermal products. The concentration of LiOH and the post-annealing temperature are the crucial factors to form LiCoMnO 4 . Without post-annealing process, the highest contents of LiCoMnO 4 in the hydrothermal products are less than 50% (e.g., in the presence of 1.2-1.35 M LiOH); in contrast, in the cases of 1.35-1.4 M LiOH, almost pure phase of LiCoMnO 4 has been achieved successfully after annealing the hydrothermal precursors at 750°C. The asprepared sample in the presence of 1.35 M LiOH, after annealed at 750°C, exhibits a capacity of 91.6 mAh g −1 .

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The origin of electrochemical activity in Li2MnO3

Abstract: The electrochemical activity of Li2MnO3 in non-aqueous media has been investigated and found to involve neither Mn(4+)-Mn5+ oxidation nor simultaneous O2- removal but exchange of Li+ by H+, the latter being generated in the electrolyte.

Cited by 195 publications

References 18 publications

Effects of synthesis on electrochemical, structural and physical properties of solution phases of Li2MnO3–LiNi1−xCoxO2

Effects of synthesis on electrochemical, structural and physical properties of solution phases of Li2MnO3–LiNi1−xCoxO2

Composite of Li-Rich Mn, Ni and Fe Oxides as Positive Electrode Materials for Li-Ion Battery

Preparation of LiCoMnO<sub>4</sub> Assisted by Hydrothermal Approach and its Electrochemical Performance

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