High‐Temperature Structural Evolution of the Disordered LiMn1.5Ni0.5O4

Vitucci, Francesco; Paolone, A.; Palumbo, O.; Greco, Giorgia; Lombardo, Lucia; Köntje, Melanie; Latini, Alessandro; Panero, S.; Brutti, Sergio

doi:10.1111/jace.14166

Cited by 9 publications

(13 citation statements)

References 28 publications

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“…Using spinel cubic phase for the LMNO, the calculated lattice parameter a was 8.221 A, a relatively high value compared to typical reports in the literature. [30][31][32] This could indicate a more disordered structure in terms of cation arrangement and/or a high ratio of larger-radius Ni to smaller-radius Mn ions. 33 The calculated lattice parameters for LAGP using a rhombohedral symmetry were a = 8.282 A and c = 20.511 A, consistent with previous reported values in the literature.…”

Section: Preparation Of Lmno and Lagp Powderssupporting

confidence: 88%

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High temperature electrode‐electrolyte interface formation between LiMn_1.5Ni_0.5O₄ and Li_1.4Al_0.4Ge_1.6(PO₄)₃

et al. 2017

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All‐solid‐state lithium‐ion electrolytes offer substantial safety benefits compared to flammable liquid organic electrolytes. However, a great challenge in solid electrolyte batteries is forming a stable and ion conducting interface between the electrolyte and active material. This study investigates and characterizes a possible solid‐state electrode‐electrolyte pair for the high voltage active cathode material LiMn1.5Ni0.5O4 (LMNO) and electrolyte Li1+xAlxGe2‐x(PO4)3 (LAGP). In situ X‐ray diffraction measurements were taken on pressed pellets comprised of a blend of LMNO and LAGP during exposure to elevated temperatures to determine the product materials that form at the interface of LMNO and LAGP and the temperatures at which they form. In particular, above 600°C a material consistent with LiMnPO4 was formed. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy were used to image the morphology and elemental compositions of product materials at the interface, and electrochemical characterization was performed on LMNO‐coated LAGP electrolyte pellet half cells. Although the voltage of Li/LAGP/LMNO assembled batteries was promising, thick interfacial phases resulted in high electrochemical resistance, demonstrating the need for further understanding and control over material processing in the LAGP/LMNO system to reduce interfacial resistance and improve electrochemical performance.

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Section: Preparation Of Lmno and Lagp Powderssupporting

confidence: 88%

“…[30][31][32] This could indicate a more disordered structure in terms of cation arrangement and/or a high ratio of larger-radius Ni to smaller-radius Mn ions. XRD patterns for the two materials can be found in Figures S1 and S2.…”

Section: Preparation Of Lmno and Lagp Powdersmentioning

confidence: 99%

High temperature electrode‐electrolyte interface formation between LiMn_1.5Ni_0.5O₄ and Li_1.4Al_0.4Ge_1.6(PO₄)₃

et al. 2017

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“…42 This process leads to the reduction of Mn 4+ to the larger Mn 3+42 and thus the expansion of the lattice parameter. 28 Additionally, a greater formation of the rock-salt impurity phase is observed.…”

Section: Resultsmentioning

confidence: 99%

Influence of Synthesis, Dopants and Cycling Conditions on the Cycling Stability of Doped LiNi_0.5Mn_1.5O₄Spinels

Höweling

Stoll

Schmidt

et al. 2017

J. Electrochem. Soc.

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The high voltage LiNi 0.5 Mn 1.5 O 4 spinel suffers from severe capacity fade when cycled against a graphitic anode as well as a relatively low theoretical capacity. Using metallic lithium as counter electrode, the stability is improved and the ability of the spinel structure to host 2 Li eq. can be used to improve the capacity. This leads to a theoretical specific energy of ∼1000 Wh kg −1 . Unfortunately, the cycling of 2 Li eq. involves a phase transition from cubic to tetragonal associated with material degradation. In this work doping is used to improve capacity retention when cycling between 2.0 and 5.0 V. Initial capacities and stabilities are directly dependent on synthesis conditions and doping elements. Therefore, Fe-and Ti-doped spinels are compared with Ru-and Ti-doped spinels and tested at different cycling conditions. The cycling stability can be improved significantly by using reannealed material and by changing the discharge cutoff criteria. Thus a capacity of 190 mAh g −1 is achieved at a rate of C/2 with a capacity retention of ∼92% after 100 cycles. Furthermore, differences in the discharge behavior between the differently treated Ru-and Ti-doped materials are discussed based on the electrochemical behavior, the particle morphology and in-situ XRD analysis. The LiNi 0.5 Mn 1.5 O 4 spinel (LNMO) is a potential candidate for a high-energy cathode material in Li ion batteries. This is due to the high operating voltage of ∼ 4.7 V vs. Li + /Li. 1,2 Regardless of the high voltage the spinel offers a lower specific energy compared with other cathode materials (e.g. Li-rich layered oxides with capacities of ca. 220 -250 mAh g −1 ). 3-5However, the ability to host an additional lithium on the 16c octahedral sites 6,7 when a lithium metal anode is used, leads to an increased specific energy. The theoretical capacity increases up to 294 mAh g −1 and a theoretical energy of around 1000 Wh kg 9,10 Furthermore the trivalent manganese is Jahn-Teller active and cycling is accompanied by a strong Jahn-Teller-distortion.7,9 The c-axis parameter is increased by ∼6% while the a-and b-axis parameters shrink by ca. 0.6% leading to a phase transition from cubic to tetragonal symmetry. 11,12 The loss of manganese and the mechanical strain due to the phase transition lead to a severe capacity fade. Therefore, stable cycling of 2 Li eq. in the LNMO\\Li metal system is not possible.In order to enhance the electrochemical stability of spinel cathode materials several studies use various elements as dopants (e.g. Cr, Fe, Ga;13 Fe, Cu, Al, Mg; 14C r, Fe, Co, Ga; 15 Ti 16 ). In many publications the positive influence of Fe-and/or Ti-doping on the electrochemical stability of LNMO has been shown. 13,14,[16][17][18][19][20] Another promising doping element is Ruthenium. It has also been investigated as dopant in previous studies for the manganese spinel 21 and the LNMO spinel. 22-25It leads to an increased rate capability due to a higher electronic conductivity as well as faster lithium diffusion. However, except from z E-mai...

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“…The peak of the Ni 2+/4+ redox couple is known as one peak for an ordered LMNO structure, while the Ni exhibits two‐step reactions, including Ni 3+/4+ and Ni 2+/3+ for a disordered LMNO structure. A peak of a Mn 3+/4+ redox couple of around 4.0 V is also commonly seen in a disordered LMNO structure ,. In addition, there was no significant difference in the CV responses between the samples of a conventional structure and a 3D structure, which was reasonable, since that structure did not affect the chemical properties.…”

Section: Figurementioning

confidence: 54%

“…Those samples when compared to the 10 % SL paste printed samples (used in this study as CO-3D), demonstrated that the areal capacity could be improved by over 25 % to 75 % to obtain a high areal capacity. This result exhibited a higher areal capacity (3.48 mAh/cm 2 ) for LMNO than the records [22][23][24] in recent five years, due to its high active material mass loading (approximately 25 mg/cm 2 ) and high specific capacity (approximately 135 mAh/g) which benefited from the 3D structure and ALD coating (Figure 2h and S5).…”

Section: Ultra-thin Coating and Three-dimensional Electrode Structurementioning

confidence: 91%

Ultra‐Thin Coating and Three‐Dimensional Electrode Structures to Boosted Thick Electrode Lithium‐Ion Battery Performance

Gao

Liu

et al. 2018

Batteries & Supercaps

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This paper reports a multiscale controlled three‐dimensional (3D) electrode structure to boost the battery performance for thick electrode batteries with LiMn1.5Ni0.5O4 as cathode material, which exhibits a high areal capacity (3.5 mAh/cm2) along with a high specific capacity (130 mAh/g). This excellent battery performance is achieved by a new concept of cell electrode fabrication, which simultaneously controls the electrode structure in a multiscale manner to address the key challenges of the material. Particles with ultrathin conformal coating layers are prepared through atomic layer deposition followed by a nanoscale‐controlled, thermal diffusion doping. The particles are organized into a macroscale‐controlled 3D hybrid‐structure. This synergistic control of nano‐/macro‐structures is a promising concept for enhancing battery performance and its cycle life. The nanoscale coating/doping provides enhanced fundamental properties, including transport and structural properties, while the mesoscale control can provide a better network of the nanostructured elements by decreasing the diffusion path between. Electrochemical tests have shown that the synergistically controlled electrode exhibits the best performance among non‐controlled and selectively‐controlled samples, in terms of specific capacity, areal capacity, and cycle life.

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High‐Temperature Structural Evolution of the Disordered LiMn_1.5Ni_0.5O₄

Cited by 9 publications

References 28 publications

High temperature electrode‐electrolyte interface formation between LiMn_1.5Ni_0.5O₄ and Li_1.4Al_0.4Ge_1.6(PO₄)₃

High temperature electrode‐electrolyte interface formation between LiMn_1.5Ni_0.5O₄ and Li_1.4Al_0.4Ge_1.6(PO₄)₃

Influence of Synthesis, Dopants and Cycling Conditions on the Cycling Stability of Doped LiNi_0.5Mn_1.5O₄Spinels

Ultra‐Thin Coating and Three‐Dimensional Electrode Structures to Boosted Thick Electrode Lithium‐Ion Battery Performance

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High‐Temperature Structural Evolution of the Disordered LiMn1.5Ni0.5O4

Cited by 9 publications

References 28 publications

High temperature electrode‐electrolyte interface formation between LiMn1.5Ni0.5O4 and Li1.4Al0.4Ge1.6(PO4)3

High temperature electrode‐electrolyte interface formation between LiMn1.5Ni0.5O4 and Li1.4Al0.4Ge1.6(PO4)3

Influence of Synthesis, Dopants and Cycling Conditions on the Cycling Stability of Doped LiNi0.5Mn1.5O4Spinels

Ultra‐Thin Coating and Three‐Dimensional Electrode Structures to Boosted Thick Electrode Lithium‐Ion Battery Performance

Contact Info

Product

Resources

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High‐Temperature Structural Evolution of the Disordered LiMn_1.5Ni_0.5O₄

High temperature electrode‐electrolyte interface formation between LiMn_1.5Ni_0.5O₄ and Li_1.4Al_0.4Ge_1.6(PO₄)₃

High temperature electrode‐electrolyte interface formation between LiMn_1.5Ni_0.5O₄ and Li_1.4Al_0.4Ge_1.6(PO₄)₃

Influence of Synthesis, Dopants and Cycling Conditions on the Cycling Stability of Doped LiNi_0.5Mn_1.5O₄Spinels