Electrochemical lithium intercalation in disordered manganese oxides

Palos, A. Ibarra

doi:10.1016/s0167-2738(00)00797-9

Cited by 28 publications

(16 citation statements)

References 10 publications

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“…This behaviour was common to samples A-D, and agrees well with other studies on amorphous or nanometric manganese oxides [22,[34][35]. The charge-discharge curve shape does not change significantly on cycling, and differs considerably from the behaviour of longrange 2D or 3D manganese oxide networks such as spinel or LiMnO 2 .…”

Section: Electrochemical Behavioursupporting

confidence: 89%

“…In 1997, Kim and Manthiram [21] reported remarkable electrochemical capacity for an oxiiodide prepared by the reaction of sodium permanganate with lithium iodide in non-aqueous medium. More recently [22], Ibarra-Palos et al showed that X-ray amorphous products could be obtained by reacting sodium permanganate with various reducing agents in aqueous medium (Cl -, I -, hydrogen peroxide, oxalic acid), The iodide route gave the best product in terms of ease of dehydration and electrochemical performances.…”

Section: Introductionmentioning

confidence: 99%

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New nanocrystalline manganese oxides as cathode materials for lithium batteries: Electron microscopy, electrochemical and X-ray absorption studies

et al. 2006

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New nanostructured manganese oxi-iodides were prepared by redox reaction of sodium permanganate with lithium iodide in aqueous medium at room temperature. Transmission electron microscopy (TEM) showed that they are nanocrystalline with grain size in the 5-10 nm range. TEM and X-ray absorption confirmed the short-range orderded structure of these compounds, which contain octahedrally coordinated manganese atoms. The electrochemical properties were studied as a function of preparation conditions (Li/Mn ratio, carbon incorporation at the synthesis stage and grinding). Best electrochemical results were obtained either on samples with carbon black incorporated directly in the aqueous reaction medium at the synthesis stage, or on samples with carbon mixed after synthesized, submitted to extensive grinding. Typical capacities in the potential window 1.8-3.8 V are160 and 130 mAh/g at the 40th and 100th cycle, respectively.Step-potential electrochemical spectroscopy and the evolution of X-ray absorption spectra on discharge are consistent with a single-phase lithium intercalation reaction with simultaneous manganese oxidation-reduction.

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Section: Electrochemical Behavioursupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

New nanocrystalline manganese oxides as cathode materials for lithium batteries: Electron microscopy, electrochemical and X-ray absorption studies

et al. 2006

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“…All reactions were carried out at room temperature in a 6-fold excess Li + with respect to NaMnO 4 concentration. Preparation details have been published elsewhere [2,8]. A new variant of this synthetic route consists in including conductive carbon black directly in the aqueous reaction medium, in order to obtain an intimate mixture oxide-carbon and to improve the electrical conductivity of the positive electrode.…”

Section: Methodsmentioning

confidence: 99%

Electrochemical lithium intercalation in nanosized manganese oxides

Strobel

Darie

Thièry

et al. 2006

Journal of Physics and Chemistry of Solids

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X-ray amorphous manganese oxides were prepared by reduction of sodium permanganate by lithium iodide in aqueous medium (MnOx-I) and by decomposition of manganese carbonate at moderate temperature (MnOx-C). TEM showed that these materials are not amorphous, but nanostructured, with a prominent spinel substructure in MnOx-C. These materials intercalate lithium with capacities up to 200 mAh/g at first cycle (potential window 1.8-4.3 V) and 175 mAh/g at 100th cycle. Best performances for MnOx-C are obtained with cobalt doping. Potential electrochemical spectroscopy shows that the initial discharge induces a 2-phase transformation in MnOx-C phases, but not in MnOx-I ones. EXAFS and XANES confirm the participation of manganese in the redox process, with variations in local structure much smaller than in known long-range crystallized manganese oxides. X-ray absorption spectroscopy also shows that cobalt in MnOx-C is divalent and does not participate in the electrochemical reaction

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“…Among the various MnO 2 species studied, amorphous or nanocrystalline compounds [9][10][11][12] and layered structures such as synthetic Birnessite [8] or synthetic Rancieite [7,13], show the most promising initial capacity in the excess of 200 mAh/g. However, such compounds still suffer from poor kinetics [14], and from capacity fading upon cycling.…”

Section: Introductionmentioning

confidence: 99%

“…As a matter of fact, this synthesis pathway is known to give rise to well-performing active materials after direct calcination of KMnO 4 [16,17] or by chemical reduction in liquid medium [7][8][9][10][11][18][19][20][21][22]. For the latter wet synthesis, a large variety of reducting agents, such as for instance oxalic acid, fumaric acid, potassium borohydride, hydrogen peroxide, lithium iodide, lithium chloride, lithium oxalate, have been investigated.…”

Section: Introductionmentioning

confidence: 99%