Temperature-Driven Chemical Segregation in Co-Free Li-Rich-Layered Oxides and Its Influence on Electrochemical Performance

Prakasha, Kunkanadu R.; Grîns, Jêkabs; Jaworski, Aleksander; Thersleff, Thomas; Svensson, Gunnar; Jøsang, Leif Olav; Dyrli, Anne Dalager; Paulus, Andreas; Sloovere, Dries De; D’Haen, Jan; Bael, Marlies K. Van; Hardy, An; Avireddy, Hemesh; Morante, Joan Ramón; Biendicho, Jordi Jacas

doi:10.1021/acs.chemmater.1c04150

Cited by 10 publications

(17 citation statements)

References 45 publications

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“…This finding is discussed in more detail in Prakasha et al. [ 24 ] Figure 5b summarizes variations to the relative nickel concentration (defined as Ni/(Ni + Mn)) from these maps in the form of a histogram. We observe that, while the histogram is roughly centered on the nominal value of 0.39, it exhibits trimodal behavior and a large spread.…”

Section: Resultsmentioning

confidence: 69%

“…A more detailed study of the parent compound is provided by Prakasha et al. [ 24 ] In this manuscript, the individual samples are named according to Table 1 .…”

Section: Resultsmentioning

confidence: 99%

“…The spectrum of the parent composition reveals an isotropic shift of 720 ppm, which changes only marginally (within ±10 ppm) among the compositions studied herein, as well as in comparison to similar compositions in our previous work. [ 24 ] The shape of the shift anisotropy pattern does not change as well across the samples. Hence, it can be assumed that oxidation states of the involved paramagnetic metal ions, on average, are the same in all samples.…”

Section: Resultsmentioning

confidence: 99%

“…[ 8,13,23 ] For example, we recently demonstrated that it is possible to achieve a core–shell morphology in Li 1.1 Ni 0.35 Mn 0.55 O 2 with the Ni‐rich R‐phase preferentially segregated to particle surfaces by combining spray‐pyrolysis with a post‐deposition calcination at 900 °C. [ 24 ] This microstructure correlated to an enhanced electrode performance, with the optimal synthesis parameters delivering 160 and 100 mAhg −1 at C/3 and 1C, respectively, with 80% capacity retention after 150 cycles.…”

Section: Introductionmentioning

confidence: 97%

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Exploring the Nanoscale Origin of Performance Enhancement in Li_1.1Ni_0.35Mn_0.55O₂ Batteries Due to Chemical Doping

Thersleff

Biendicho

Prakasha

et al. 2023

Advanced Energy Materials

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While cathode materials with a layered structure containing Co such as LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC111) can currently provide high capacities, their use for next-generation Li-ion batteries is limited by the high toxicity, cost, and ethical issues associated with cobalt mining. [3,4] Due to the strategic importance of Co reduction or elimination, a wide range of alternative compounds and lithium chemistries are currently being researched; [5] however, most of these exhibit significant drawbacks compared to NMC111. For example, olivine (LiFePO 4 ) [6] and spinel (LiNi 0.5 Mn 1.5 O 4 ) [7] based materials have interesting properties such as being Co-free, low cost and presenting high C-rate performance for rapid battery charging, but their capacity is limited to <200 mAhg −1 . Ni-rich layered oxides with low cobalt content, for example, LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NMC622) and LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) deliver high energy densities but suffer from slow kinetics and poor cycling stability requiring complex engineering at the particle level to enhance performance. [8,9] Additionally, these materials are prone to reactivity and instability upon exposure to ambient conditions [10] and their price has increased lately.In addition to the aforementioned compounds, it is also possible to fabricate Co-free cathode materials based off the layered Li-Mn-rich oxides. These form complex nanocomposite structures due to their nanoscale integration of two structural components: a monoclinic C2/m Li 2 MnO 3 -like phase (M-phase) and a rhombohedral R-3m LiMn 1/2 Ni 1/2 O 2 -like phase (R-phase). [11,12] The presence of both structures as a nanocomposite material is desirable, as they differ in their cation ordering and are active at different potentials up to 4.6 V versus Li + /Li, thereby maximizing energy density. However, without the inclusion of Co, these nanocomposites show limited capacity retention, poor efficiencies, severe voltage fade, and a failure to deliver capacity at high C-rates. [13,14] Several approaches have been discussed in the literature to improve the performance of this system, and some of the most promising results have been obtained by chemical doping. [13,15,16] For instance, Al-doped samples showed superior cycling performance and lower voltage decay than parent compositions, [17][18][19] which was attributed to a robust R-phase stabilizing the overall structure while blocking the random growth of spinel-like phases. [17] The effect Despite significant potential as energy storage materials for electric vehicles due to their combination of high energy density per unit cost and reduced environmental and ethical concerns, Co-free lithium ion batteries based on layered Mn oxides presently lack the longevity and stability of their Co-containing counterparts. Here, a reduction in this performance gap is demonstrated via chemical doping, with Li 1.1 Ni 0.35 Mn 0.54 Al 0.01 O 2 achieving an initial discharge capacity of 159 mAhg −1 at C/3 rate and a corresponding capacity retention of 94.3% after 150 ...

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Section: Resultsmentioning

confidence: 69%

“…A more detailed study of the parent compound is provided by Prakasha et al. [ 24 ] In this manuscript, the individual samples are named according to Table 1 .…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

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Exploring the Nanoscale Origin of Performance Enhancement in Li_1.1Ni_0.35Mn_0.55O₂ Batteries Due to Chemical Doping

Thersleff

Biendicho

Prakasha

et al. 2023

Advanced Energy Materials

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“…Turning to other Co-free stoichiometries, Prakasha et al [103] investigated the effect of the calcination temperature on the structural properties and the electrochemical performance of an LRLO with composition Li1.1Ni0.35Mn0.55O2. This material was synthesized by the use of spray-pyrolysis combined with a calcination at 900°C.…”

Section: Co-free Lrlosmentioning

confidence: 99%

Li-Rich Layered Oxides: Structure and Doping Strategies to Enable Co-poor/Co-free Cathodes for Li-Ion Batteries

Silvestri¹,

Tuccillo²,

Celeste³

et al. 2022

Preprint

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Lithium rich layered oxides (LRLO) are a wide class of innovative active materials for positive electrodes in lithium-ion (LIB) and lithium-metal secondary batteries (LMB). LRLOs are over-stoichiometric layered oxides rich in lithium and manganese, with general formula Li1+xTM1-xO2, where TM is a blend of transition metals comprising Mn (main constituent), Ni, Co, Fe and others. Due to the very variable composition and the extended defectivity their structural identity is still debated among researchers being likely an unresolved hybrid between a monoclinic (mC24) and a hexagonal lattice (hR12). Once casted in composite positive electrode films and assembled in LIBs or LMBs, LRLOs can delivery reversible specific capacities above 220-240 mAhg-1, thus beyond any other available intercalation cathode material for LIBs, with mean working potential above 3.3-3.4 V vs Li for hundreds of cycles in liquid aprotic commercial electrodes. In this review we critically outline the recent advancements in the fundamental understanding of the physico-chemical properties of LRLO as well as the most exciting innovations in their battery performance. We focus in particular on the elusive structural identity of these phases, on the complexity of the reaction mechanism in batteries as well as on practical strategies to minimize or remove cobalt from the lattice while preserving the outstanding performance upon cycling.

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Phase Engineering via Aluminum Doping Enhances the Electrochemical Stability of Lithium‐Rich Cobalt‐Free Layered Oxides for Lithium‐Ion Batteries

De Sloovere,

Mylavarapu,

D'Haen

et al. 2024

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Lithium‐rich, cobalt‐free oxides are promising potential positive electrode materials for lithium‐ion batteries because of their high energy density, lower cost, and reduced environmental and ethical concerns. However, their commercial breakthrough is hindered because of their subpar electrochemical stability. This work studies the effect of aluminum doping on Li1.26Ni0.15Mn0.61O2 as a lithium‐rich, cobalt‐free layered oxide. Al doping suppresses voltage fade and improves the capacity retention from 46% for Li1.26Ni0.15Mn0.61O2 to 67% for Li1.26Ni0.15Mn0.56Al0.05O2 after 250 cycles at 0.2 C. The undoped material has a monoclinic Li2MnO3‐type structure with spinel on the particle edges. In contrast, Al‐doped materials (Li1.26Ni0.15Mn0.61‐xAlxO2) consist of a more stable rhombohedral phase at the particle edges, with a monoclinic phase core. For this core‐shell structure, the formation of Mn3+ is suppressed along with the material's decomposition to a disordered spinel, and the amount of the rhombohedral phase content increases during galvanostatic cycling. Whereas previous studies generally provided qualitative insight into the degradation mechanisms during electrochemical cycling, this work provides quantitative information on the stabilizing effect of the rhombohedral shell in the doped sample. As such, this study provides fundamental insight into the mechanisms through which Al doping increases the electrochemical stability of lithium‐rich cobalt‐free layered oxides.

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Temperature-Driven Chemical Segregation in Co-Free Li-Rich-Layered Oxides and Its Influence on Electrochemical Performance

Cited by 10 publications

References 45 publications

Exploring the Nanoscale Origin of Performance Enhancement in Li_1.1Ni_0.35Mn_0.55O₂ Batteries Due to Chemical Doping

Exploring the Nanoscale Origin of Performance Enhancement in Li_1.1Ni_0.35Mn_0.55O₂ Batteries Due to Chemical Doping

Li-Rich Layered Oxides: Structure and Doping Strategies to Enable Co-poor/Co-free Cathodes for Li-Ion Batteries

Phase Engineering via Aluminum Doping Enhances the Electrochemical Stability of Lithium‐Rich Cobalt‐Free Layered Oxides for Lithium‐Ion Batteries

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Temperature-Driven Chemical Segregation in Co-Free Li-Rich-Layered Oxides and Its Influence on Electrochemical Performance

Cited by 10 publications

References 45 publications

Exploring the Nanoscale Origin of Performance Enhancement in Li1.1Ni0.35Mn0.55O2 Batteries Due to Chemical Doping

Exploring the Nanoscale Origin of Performance Enhancement in Li1.1Ni0.35Mn0.55O2 Batteries Due to Chemical Doping

Li-Rich Layered Oxides: Structure and Doping Strategies to Enable Co-poor/Co-free Cathodes for Li-Ion Batteries

Phase Engineering via Aluminum Doping Enhances the Electrochemical Stability of Lithium‐Rich Cobalt‐Free Layered Oxides for Lithium‐Ion Batteries

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Exploring the Nanoscale Origin of Performance Enhancement in Li_1.1Ni_0.35Mn_0.55O₂ Batteries Due to Chemical Doping

Exploring the Nanoscale Origin of Performance Enhancement in Li_1.1Ni_0.35Mn_0.55O₂ Batteries Due to Chemical Doping