In-depth structural characterization of the influence of Li+ excess on spherical, Co-free layered LiMn0.5Ni0.5O2 cathode material using correlative Raman–SEM microscopy

Klein, Florian; Pfeifer, Claudia; Scheitenberger, Philipp; Pfeiffer, Lukas; Zimmer, Dominik; Wohlfahrt‐Mehrens, Margret; Lindén, Mika; Axmann, Peter

doi:10.1039/d2ta05957f

Cited by 5 publications

(3 citation statements)

References 80 publications

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“…These materials typically exhibit superlattice ordering of type a a 3 3 . √ × √ 21,35 Increasing amounts of Na substitution reduce the intensity of this ordering. Figures 2c and 2d demonstrate that the peaks (003), ( 104), ( 108), (110) move towards the left with increasing Na, indicating an increase in d spacing but without affecting crystallinity.…”

Section: Resultsmentioning

confidence: 99%

Substituting Na for Excess Li in Li_1+x(Ni_0.6Mn_0.4)_1−xO₂ Materials

Rathore,

Perez,

Monchesky

et al. 2024

J. Electrochem. Soc.

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NMC640, a series of Li1+x(Ni0.6Mn0.4)1-xO2 materials, are important Co-free mid-Ni cathode materials for Li-ion batteries, offering high energy density and better cost-efficiency than Ni-rich counterparts. These materials require excess Li compared to stoichiometric composition to improve the electrochemical performance in terms of rate capability and cycling stability. Although lithium-to-transition metal ratios up to 1.15 can be used to optimize the performance, less than 80% of this lithium is electrochemically active during cycling up to a 4.4 V upper cut off. This study explores whether some percentage of the inactive Li can be replaced by sodium to make these materials more cost-effective and bring potential improvements in electrochemical performance. Various amounts of excess Li were substituted by sodium in the structure. The results show that sodium can be integrated into the layered oxide structure without forming any impurity phases and effectively decreases the cation mixing observed in these layered structures. However, this does compromise cycling stability and rate capability. Na tends to occupy Li sites rather than transition metal sites, resulting in electrochemical instability and capacity loss. Even though excess Li is not electrochemically active, it cannot be effectively replaced by sodium without compromising battery performance of Li1+x(Ni0.6Mn0.4)1-xO2 materials.

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Section: Resultsmentioning

confidence: 99%

Substituting Na for Excess Li in Li_1+x(Ni_0.6Mn_0.4)_1−xO₂ Materials

Rathore,

Perez,

Monchesky

et al. 2024

J. Electrochem. Soc.

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“…This situation could flip the availability and long-term viability of the metal in the future. Klein et al 18 synthesized Co-free lithium LiMn 0.5 Ni 0.5 O 2 layer using excess of Li + obtained an initial discharge capacity of 173 mAh g −1 . However, the retention capacity was seemed only when an excess of 7% of lithium was used.…”

mentioning

confidence: 99%

“…However, the retention capacity was seemed only when an excess of 7% of lithium was used. 18 Moreover, the work only showed 40 cycles and the retention capacity was not reported.…”

mentioning

confidence: 99%

Cobalt-Free Oxide Cathode Material with Phase Composition Control to High Electrochemical Performance in Li-Ion Batteries

Agudelo,

Vasquez,

Calderón

2024

J. Electrochem. Soc.

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Cobalt-free layered oxide cathode material (LiMn0.5Ni0.5O2) was obtained via a two-step synthesis method. First, hydrothermal synthesis of MnOOH with nanorod morphology was achieved and then a co-precipitation process to obtain the LiMn0.5Ni0.5O2 active layered material was performed. Structural and morphological characterization revealed a promising disordered layered structure obtained at 800°C with improved electrochemical performance. The thermal treatment performed on the active materials resulted in a controlled balance between the monoclinic and rhombohedral phase leading to good phases formation ratio in a cobalt-free layer cathode. It was found that the controlled mixing of structural phases plays an important role in improving the electrochemical performance of the active cathodic layer material, resulting in an adequate balance between high discharge capacity and electrochemical stability during the charge/discharge cycling. The morphological analysis showed two kinds of particles that played an important role in the structural stability and electrochemical performance. The active material thermally treated at 800°C displayed outstanding discharge capacity of 235.05 mAh g-1 at 20 mA g-1 in current constant-constant voltage) mode. While, in current constant mode showed the highest discharge capacity, of 178.95 mAh g-1 at 20 mA g-1 and good capacity retention (87.2% after 100 cycles).

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Borate modified Co-free LiNi0.5Mn1.5O4 cathode material: A pathway to superior interface and cycling stability in LNMO/graphite full-cells

Nisar,

Bansmann,

Hebel

et al. 2024

Chemical Engineering Journal

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In-depth structural characterization of the influence of Li⁺ excess on spherical, Co-free layered LiMn_0.5Ni_0.5O₂ cathode material using correlative Raman–SEM microscopy

Abstract: Structural evidence of a Li+ induced phase segregation on particle level in Co-free layered Li–Mn–Ni-oxide cathode materials for Li-ion batteries is presented, illustrating the importance of correlative SEM–Raman microscopy in battery research.

Cited by 5 publications

References 80 publications

Substituting Na for Excess Li in Li_1+x(Ni_0.6Mn_0.4)_1−xO₂ Materials

Substituting Na for Excess Li in Li_1+x(Ni_0.6Mn_0.4)_1−xO₂ Materials

Cobalt-Free Oxide Cathode Material with Phase Composition Control to High Electrochemical Performance in Li-Ion Batteries

Borate modified Co-free LiNi0.5Mn1.5O4 cathode material: A pathway to superior interface and cycling stability in LNMO/graphite full-cells

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In-depth structural characterization of the influence of Li+ excess on spherical, Co-free layered LiMn0.5Ni0.5O2 cathode material using correlative Raman–SEM microscopy

Abstract: Structural evidence of a Li+ induced phase segregation on particle level in Co-free layered Li–Mn–Ni-oxide cathode materials for Li-ion batteries is presented, illustrating the importance of correlative SEM–Raman microscopy in battery research.

Cited by 5 publications

References 80 publications

Substituting Na for Excess Li in Li1+x(Ni0.6Mn0.4)1−xO2 Materials

Substituting Na for Excess Li in Li1+x(Ni0.6Mn0.4)1−xO2 Materials

Cobalt-Free Oxide Cathode Material with Phase Composition Control to High Electrochemical Performance in Li-Ion Batteries

Borate modified Co-free LiNi0.5Mn1.5O4 cathode material: A pathway to superior interface and cycling stability in LNMO/graphite full-cells

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Product

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In-depth structural characterization of the influence of Li⁺ excess on spherical, Co-free layered LiMn_0.5Ni_0.5O₂ cathode material using correlative Raman–SEM microscopy

Substituting Na for Excess Li in Li_1+x(Ni_0.6Mn_0.4)_1−xO₂ Materials

Substituting Na for Excess Li in Li_1+x(Ni_0.6Mn_0.4)_1−xO₂ Materials