Thermodynamic analysis using first-principles calculations of phases and structures of LixNi0.5Mn1.5O4 (0 ≤ x ≤ 1)

Kishida, Ippei; Orita, Kengo; Nakamura, Atsutomo; Yokogawa, Yoshiyuki

doi:10.1016/j.jpowsour.2013.04.099

Cited by 11 publications

(9 citation statements)

References 30 publications

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“…Thus, in the analogue case of Li 0.5 Ni 0.5 Mn 1.5 O 4 in P 2 1 3 symmetry, Li orders by fully occupying a single 4 a tetrahedral position, compared to an occupancy of 0.5 at the 8 c tetrahedral position in P 4 3 32 symmetry (Figure c). Refining the model to the 320 °C dataset with P 2 1 3 symmetry and allowing for Li to freely occupy both of the tetrahedral 4 a positions led to Li occupying specifically one of the two sites, i.e., the (0.0189 (14), 0.0189 (14), 0.0189 (14)) position, in agreement with the thermodynamically most stable Li configuration found from first-principles calculations on Li 0.5 Ni 0.5 Mn 1.5 O 4 . This resulted in a successful fit to the (200) reflection, as shown in Figure a,b.…”

Section: Resultssupporting

confidence: 67%

Low-Temperature Cation Ordering in High Voltage Spinel Cathode Material

Gustafsson

Kullgren

Brant

2023

ACS Appl. Energy Mater.

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The spinel cathode LiNi 0.5 Mn 1.5 O 4 (LNMO) is a promising material for battery applications; however, issues regarding its cycling stability need to be addressed to fully utilize its potential. Specifically, LNMO suffers from rapid capacity loss following prolonged electrochemical cycling where the capacity drop occurs at an earlier stage for its transition metal ordered form. Further, the disordered form has been found to partially order during cycling, leading to the question if the failing of the disordered form is driven by Ni and Mn ordering in the structure. However, ordering is usually initiated at temperatures above 700 °C in the fully lithiated state, sparking the question if the energy barrier for the ordering process is lowered at the reduced Li content. In the work presented here, in situ neutron diffraction was used to further elucidate the ordering temperature and thermal stability of Li x Ni 0.5 Mn 1.5 O 4 (0.000 (10) ≤ x ≤ 0.675 ( 10)). The temperature for Ni and Mn ordering was found to be dramatically lowered to 310−320 °C for Li x Ni 0.5 Mn 1.5 O 4 compositions of 0.222 (8) ≤ x ≤ 0.675 (10), explained by a lower energy barrier for formation of intermediate Frenkel defect states. Li ordering and a lowering of symmetry to P2 1 3, together with formation of both a NiMn 2 O 4 -type spinel phase and a NiMnO 3 -type phase, could also be observed. The formation of NiMn 2 O 4 -and NiMnO 3 -type phases could be linked to reorganization of transition metals (TM) within the spinel structure and were found to be in competition with Ni and Mn ordering. At higher Li contents, transition metal diffusion tended to favor Ni and Mn ordering, while NiMn 2 O 4 -and NiMnO 3 -type phases were formed to a greater extent at lower Li contents. These results highlight the importance of suppressing transition metal reorganization in LiNi 0.5 Mn 1.5 O 4 , via increased TM diffusion energy barriers, as a key strategy for minimizing structural rearrangements and ultimately improving its electrochemical cyclability.

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Section: Resultssupporting

confidence: 67%

Low-Temperature Cation Ordering in High Voltage Spinel Cathode Material

Gustafsson

Kullgren

Brant

2023

ACS Appl. Energy Mater.

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“…Recently, Kishida et al performed a thermodynamic analysis of L x MNO (0 ≤ x ≤ 1), and their calculations showed that x = 0, 0.5, and 1 are the most stable phases in the system at 0 K, consistent with the experimental detection of the three phases during Li extraction and insertion of LMNO. 36 However, their decomposition energy was comparable to that of other compositions, with a difference as small as ∼0.4 eV calculated. This indicates that less stable L x MNO phases may easily form under external stimulus.…”

Section: Resultsmentioning

confidence: 54%

“…The thermally driven solid solution, however, can be isolated and maintained at room temperature for a long period of time. Recently, Kishida et al performed a thermodynamic analysis of L x MNO (0 ≤ x ≤ 1), and their calculations showed that x = 0, 0.5, and 1 are the most stable phases in the system at 0 K, consistent with the experimental detection of the three phases during Li extraction and insertion of LMNO . However, their decomposition energy was comparable to that of other compositions, with a difference as small as ∼0.4 eV calculated.…”

Section: Resultsmentioning

confidence: 76%

Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

et al. 2017

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For ordered high-voltage spinel LiMn 1.5 Ni 0.5 O 4 (LMNO) with the P4 3 2 1 symmetry, the two consecutive twophase transformations at ∼4.7 V (vs Li + /Li), involving three cubic phases of LMNO, Li 0.5 Mn 1.5 Ni 0.5 O 4 (L 0.5 MNO), and Mn 1.5 Ni 0.5 O 4 (MNO), have been well-established. Such a mechanism is traditionally associated with poor kinetics due to the slow movement of the phase boundaries and the large mechanical strain resulting from the volume changes among the phases, yet ordered LMNO has been shown to have excellent rate capability. In this study, we show the ability of the phases to dissolve into each other and determine their solubility limit. We characterized the properties of the formed solid solutions and investigated the role of non-equilibrium single-phase redox processes during the charge and discharge of LMNO. By using an array of advanced analytical techniques, such as soft and hard X-ray spectroscopy, transmission X-ray microscopy, and neutron/X-ray diffraction, as well as bond valence sum analysis, the present study examines the metastable nature of solidsolution phases and provides new insights in enabling cathode materials that are thermodynamically unstable.

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“…Destabilization of the LiNi 0.5 Mn 1.5 O 4 structure, accompanied by a loss of oxygen during cycling, is possibly responsible for the migration of TM ions associated with the formation of the locally distorted structures. This cathode material, as well as many others, is highly oxidative and unstable, particularly in the charged (delithiated) stage, as indicated by experimental ,,,− and computational ,− studies. Thus, they are prone to the migration of TM ions to form more stable structures, accompanied by a loss of oxygen.…”

Section: Discussionmentioning

confidence: 99%

Insight into the Atomic Structure of High-Voltage Spinel LiNi_0.5Mn_1.5O₄ Cathode Material in the First Cycle

et al. 2014

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Application of high-voltage spinel LiNi 0.5 Mn 1.5 O 4 cathode material is the closest and the most realistic approach to meeting the midterm goal of lithium-ion batteries for electric vehicles (EVs) and plug-in hybrid electric vehicles (HEVs). However, this application has been hampered by long-standing issues, such as capacity degradation and poor first-cycle Coulombic efficiency of LiNi 0.5 Mn 1.5 O 4 cathode material. Although it is well-known that the structure of LiNi 0.5 Mn 1.5 O 4 into which Li ions are reversibly intercalated plays a critical role in the above issues, performance degradation related to structural changes, particularly in the first cycle, are not fully understood. Here, we report detailed investigations of local atomic-level and average structure of LiNi 0.5 Mn 1.5 O 4 during first cycle (3.5−4.9 V) at room temperature. We observed two types of local atomic-level migration of transition metals (TM) ions in the cathode of a well-prepared LiNi 0.5 Mn 1.5 O 4 //Li half-cell during first charge via an aberration-corrected scanning transmission electron microscopy (STEM). Surface regions (∼2 nm) of the cycled LiNi 0.5 Mn 1.5 O 4 particles show migration of TM ions into tetrahedral Li sites to form a Mn 3 O 4 -like structure. However, subsurface regions of the cycled particles exhibit migration of TM ions into empty octahedral sites to form a rocksalt-like structure. The migration of these TM ions are closely related to dissolution of Ni/Mn ions and building-up of charge transfer impedance, which contribute significantly to the capacity degradation and the poor first-cycle Coulombic efficiency of spinel LiNi 0.5 Mn 1.5 O 4 cathode material. Accordingly, we provide suggestions of effective stabilization of LiNi 0.5 Mn 1.5 O 4 structure to obtain better electrochemical performance.

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Thermodynamic analysis using first-principles calculations of phases and structures of LixNi0.5Mn1.5O4 (0 ≤ x ≤ 1)

Cited by 11 publications

References 30 publications

Low-Temperature Cation Ordering in High Voltage Spinel Cathode Material

Low-Temperature Cation Ordering in High Voltage Spinel Cathode Material

Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

Insight into the Atomic Structure of High-Voltage Spinel LiNi_0.5Mn_1.5O₄ Cathode Material in the First Cycle

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Thermodynamic analysis using first-principles calculations of phases and structures of LixNi0.5Mn1.5O4 (0 ≤ x ≤ 1)

Cited by 11 publications

References 30 publications

Low-Temperature Cation Ordering in High Voltage Spinel Cathode Material

Low-Temperature Cation Ordering in High Voltage Spinel Cathode Material

Crystal Chemistry and Electrochemistry of LixMn1.5Ni0.5O4 Solid Solution Cathode Materials

Insight into the Atomic Structure of High-Voltage Spinel LiNi0.5Mn1.5O4 Cathode Material in the First Cycle

Contact Info

Product

Resources

About

Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

Insight into the Atomic Structure of High-Voltage Spinel LiNi_0.5Mn_1.5O₄ Cathode Material in the First Cycle