Atomic structure and lattice dynamics of Ni and Mg hydroxides

Kazimirov, V. Yu.; Smirnov, M. B.; Bourgeois, Lydie; Guerlou‐Demourgues, Liliane; Servant, Laurent; Балагуров, А. М.; Natkaniec, I.; Khasanova, Nellie R.; Антипов, Е.В.

doi:10.1016/j.ssi.2010.10.002

Cited by 87 publications

(89 citation statements)

References 40 publications

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“…In β-and γ-NiOOH the distance between the Ni-O planes is over 4.6 Å, and in Ni(OH) 2 •xH 2 O it increases to 7.6 Å, as the water molecules enter the spaces between the protonated Ni-O layers. 28,75 These large lattice parameters seemingly argue against such crystal structures as models of the protonated material in our case; however, if only some of the Li + ions are replaced by H + ions, one can expect contraction rather than expansion, since the smaller proton would interact stronger with the oxygens and in this way more efficiently screen the repulsion between them.…”

Section: Discussion: H + /Li + Exchange Hypothesismentioning

confidence: 78%

Chemical Weathering of Layered Ni-Rich Oxide Electrode Materials: Evidence for Cation Exchange

Shkrob

Gilbert

Phillips

et al. 2017

J. Electrochem. Soc.

141

160

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Lithiated ternary oxides containing nickel, cobalt, and manganese are intercalation compounds that are used as positive electrodes in high-energy lithium-ion batteries. These oxides undergo changes, when they are stored in humid air or exposed to moisture, that adversely affect their electrochemical performance. There is a new urgency to better understanding of these "weathering" mechanisms as manufacturing moves toward a more environmentally benign aqueous processing of the positive electrode. Delithiation of the oxide and the formation of lithium salts (such as hydroxides and carbonates) coating the surface, are known to occur during moisture exposure. The redox reactions which follow this delithiation are believed to trigger all the other transformations. In this article we suggest another possibility: namely, the proton -lithium exchange. We argue that this hypothesis provides a simple, comprehensive rationale for our observations, which include contraction of the c-axis (unit cell) lattice parameter, rock salt phase formation in the subsurface regions, presence of amorphous surface films, and the partial recovery of oxide capacity during electrochemical relithiation. The detrimental effects of water exposure need to be mitigated before aqueous processing of the positive electrode can find widespread adoption during cell manufacturing. Improving the performance of lithium-ion batteries (LIBs) for electrically powered vehicles gives urgency to the development of high-capacity, high-voltage electrode materials, and layered Ni-rich oxides are presently among the most technological advanced materials that allow operation above +4.0 V vs Li + /Li. 1 Such materials (also known as NCMxyz materials) have the general composition of LiNi x/10 Co y/10 Mn z/10 O 2 , where x+y+z = 10. In these ternary oxides, the manganese stays in the Mn 4+ state during cell cycling, and the capacity mainly originates from the Ni 2+ /Ni 3+ and Ni 3+ /Ni 4+ redox couples. The monolayers of octahedra containing transition metal (TM) ions form a structural scaffold with the layers of mobile Li + ions placed in between. The crystalline material retains the structure of the progenitor material of the family, viz. α-LiCoO 2 , 2 with the unit cell belonging to the rhombohedral R(-3)m space group. During electrochemical cycling, the lithium ions intercalate into (and deintercalate from) the layered crystals as the redox state of (mainly the) nickel ions changes to provide the overall charge neutrality.In this study, we examine one such material, NCM523, which represents a particular trade-off between the cycling rate (that improves with Co content), safety (that improves with Mn content), and capacity (that increases with Ni content).1 The safety concerns mainly relate to the thermal and chemical stability, including oxidation of the organic electrolyte by catalytic centers at the oxide surface 3 and phase transitions in the delithiated material that occur when a significant fraction of nickel ions is reduced to Ni 2+ ions and molecular oxygen ...

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Section: Discussion: H + /Li + Exchange Hypothesismentioning

confidence: 78%

Chemical Weathering of Layered Ni-Rich Oxide Electrode Materials: Evidence for Cation Exchange

Shkrob

Gilbert

Phillips

et al. 2017

J. Electrochem. Soc.

141

160

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“…Since there are no trivalent cations when x = 0, this value of c 0 corresponds to the situation where the main hydroxide layer is electroneutral and so there would be no anions in the interlayer. This interlayer spacing is very much greater than the value for -Ni(OH) 2 -which is 4.606 Å (Kazimirov et al, 2010) -and so there must be something in the interlayer region that keeps the hydroxide layers so far apart. It seems reasonable to suggest that the expanded interlayer is due to the presence of water molecules, i.e.…”

Section: Layered Double Hydroxidesmentioning

confidence: 75%

“…For a regular octahedron, the bond angle is 90 and so the a parameter is given by equation (7), d MÀO ð Þ¼a=2 1=2 , and (Catti et al, 1995;Č erný et al, 1995;Chakoumakos et al, 1997;Desgranges et al, 1996;Isetti, 1965;Zigan & Rothbauer, 1967), Ni(OH) 2 (Kazimirov et al, 2010), Co(OH) 2 (Pertlik, 1999), Fe(OH) 2 (Parise et al, 2000), Mn(OH) 2 (Christensen & Ollivier, 1972), Cd(OH) 2 (Bertrand & Dusausoy, 1970), Ca(OH) 2 (Busing & Levy, 1957) Brindley & Kao (1984) presented a similar figure but used values of d(M-O) that were calculated using ionic radii rather than those determined by experiment. The data point for -Zn(OH) 2 is clearly anomalous (the structure is from Baneyeva & Popova, 1969) and whilst an approximate value for its a parameter can be calculated using equation (4) (using = 98.3 and the effective ionic radii of the Zn 2+ and OH À ions), the value of a is actually very sensitive to the value of for the level of precision that is necessary and an accurate value for the effective radius of the O atom of the hydroxyl ion is also needed.…”

Section: Geometrical Relationships In the Octahedral Layer Of Single mentioning

confidence: 99%

The importance of proper crystal-chemical and geometrical reasoning demonstrated using layered single and double hydroxides

Richardson¹

2013

Acta Crystallogr Sect B

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Atomistic modelling techniques and Rietveld refinement of Xray powder diffraction data are widely used but often result in crystal structures that are not realistic, presumably because the authors neglect to check the crystal-chemical plausibility of their structure. The purpose of this paper is to reinforce the importance and utility of proper crystal-chemical and geometrical reasoning in structural studies. It is achieved by using such reasoning to generate new yet fundamental information about layered double hydroxides (LDH), a large, much-studied family of compounds. LDH phases are derived from layered single hydroxides by the substitution of a fraction (x) of the divalent cations by trivalent. Equations are derived that enable calculation of x from the a parameter of the unit cell and vice versa, which can be expected to be of widespread utility as a sanity test for extant and future structure determinations and computer simulation studies. The phase at x = 0 is shown to be an form of divalent metal hydroxide rather than the polymorph. Crystal-chemically sensible model structures are provided for -Zn(OH) 2 and Niand Mg-based carbonate LDH phases that have any trivalent cation and any value of x, including x = 0 [i.e. for -M(OH) 2 ÁmH 2 O phases].

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“…Because of high power, high energy density, good safety, Ni-MH battery is widely used in power tools to electric vehicles or hybrid electric vehicles, portable electronics, UPS [1]. As is well-known, there are two polymorphs known as a-Ni(OH) 2 and b-Ni(OH) 2 phase, which in the oxidation process convert to g-NiOOH and bNiOOH, respectively [2].…”

Section: Introductionmentioning

confidence: 99%

The relationship between structural stability and electrochemical performance of multi-element doped alpha nickel hydroxide

Miao

Zhu

Huang

et al. 2015

Journal of Power Sources

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Atomic structure and lattice dynamics of Ni and Mg hydroxides

Cited by 87 publications

References 40 publications

Chemical Weathering of Layered Ni-Rich Oxide Electrode Materials: Evidence for Cation Exchange

Chemical Weathering of Layered Ni-Rich Oxide Electrode Materials: Evidence for Cation Exchange

The importance of proper crystal-chemical and geometrical reasoning demonstrated using layered single and double hydroxides

The relationship between structural stability and electrochemical performance of multi-element doped alpha nickel hydroxide

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