Electrochemical studies on cathode blends of LiMn2O4 and Li[Li1/15Ni1/5Co2/5Mn1/3O2]

Jeong, Soo Kyung; Shin, Jae Sun; Nahm, Kee Suk; Kumar, T. Prem; Stephan, A. Manuel

doi:10.1016/j.matchemphys.2008.03.032

Cited by 46 publications

(13 citation statements)

References 31 publications

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“…Blending different kinds of active materials is a promising approach to improve the properties of electrodes for lithiumion batteries (LIBs). [1] Layered-layered, [2] spinel-spinel, [3][4][5][6] layered-olivine [7,8] and spinel-olivine mixtures [9,10] exhibit great improvements concerning safety, [2,3] rate capability [11,12] and also cycle stability. [4][5][6]13] Despite these promising perspectives, basic interactions, especially the specific influence of the single components on the properties of the blend, are not satisfactorily understood at the moment.…”

Section: Introductionmentioning

confidence: 99%

Investigations on the Effective Electric Loads in Blended Insertion Electrodes for Lithium‐Ion Batteries

et al. 2019

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Blending different types of active materials in one electrode is a great opportunity to improve the overall performance of lithium‐ion batteries. Despite considerable progress in the recent years, basic interactions, such as the specific impact of a single component on the blends’ properties, are not satisfactorily understood at the moment. In this study, the electric loads of the individual components of a blend are investigated using a special experimental setup in combination with model‐like blended electrodes. Systematic studies on the impact of type and mass fraction of the components are conducted for different nominal charge and discharge rates. The experiments reveal that the single components can be charged and discharged independent from each other, according to their characteristic redox activities and the overpotential during operation. This can lead to high effective electric loads (C‐rates) subjected to a single component despite a comparatively low total current applied to the electrode. Based on the experimental results, a simple model is developed to estimate maximum effective C‐rates of the individual components in an arbitrary blend system. These novel insights are discussed in regarding advantages and disadvantages of battery electrodes with multiple active materials.

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Section: Introductionmentioning

confidence: 99%

Investigations on the Effective Electric Loads in Blended Insertion Electrodes for Lithium‐Ion Batteries

et al. 2019

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“…Kinetic origin.-As the over-lithiation of LMO being identified, it is interesting to know under what conditions it could happen. Although this LMO to Li 2 Mn 2 O 4 reaction has been reported in half-cell experiments for composite electrodes vs. a Li electrode, 6 where Liion is in excess; it is difficult to conceive how this over-lithiation of LMO could occur in a full cell, since the accessible Li content should be constrained by the initial Li content in the PE. In a typical discharge regime, at the EOD ideally all lithium ions should be retained in the PE where NMC and LMO are supposed to be fully lithiated to their respective state of charge, where kinetic charge balance or thermodynamic equilibrium could be attained.…”

Section: Discussionmentioning

confidence: 94%

“…A useful reference is the review provided by Thackeray, 5 which summarized the various compositions in the Li-Mn-O ternary system and their behavior as active cathode materials in battery applications. The work reported by Jeong et al 6 and by Wu and Yu 7 showed more current trends in utilizing such compositions in possible Li-ion battery applications. Although the exact composition in the commercial cells tested in this work was not known, the similarity in the cell behavior as revealed in the work of Jeong et al 6 compared to ours gives us some basis for discussion to aid the understanding of the overdischarge behavior of the cell under evaluation in this work.…”

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confidence: 97%

Evaluation of Commercial Lithium-Ion Cells Based on Composite Positive Electrode for Plug-In Hybrid Electric Vehicle (PHEV) Applications

Dubarry

Truchot

Devie

et al. 2015

J. Electrochem. Soc.

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Lithium-ion cells with composite positive electrodes are attractive and promising for EV and PHEV applications. For powertrain applications, the battery packs are required to have multiple-cell configurations, where some battery management is needed to protect cells from experiencing overcharging and overdischarging. Here, we show how to analyze the effect of slight overdischarge in a graphite || {Li x Mn 1/3 Ni 1/3 Co 1/3 O 2 + Li x Mn 2 O 4 } cell, when it was overdischarged to 2.0 V. We found a peculiar behavior at low voltages that is imputable to the composite nature of the positive electrode. Under certain circumstances, due to differences in kinetic limitations in each of the constituents in the composite electrode, although Li-ion batteries with graphite intercalation compounds (G) as negative electrodes (NE) and mechanically blended compositions nominally denoted as {Li x Mn a Ni b Co c O 2 (NMC) + Li x Mn 2 O 4 (LMO)} as composite positive electrodes (c-PE) could be attractive for plugin hybrid electric vehicle (PHEV) applications due to their ability of combining high power (rate capability) and high energy aspects. 1To acquire sufficient understanding of the performance of this type of cells, studies on various subjects, including aging process and degradation mechanism, quantification of cell-to-cell variations (cell variability) among a small quantity of cells; 2 the rate capability over a range of rates; 2 quantification of attributes from various degradation modes to capacity fading in a 2C cycle aging regime; 3 and, the amount of reversible and irreversible capacity fading at different temperatures in a temperature excursion; 4 have been reported in our previous studies. Here, a study with illustrations of computer model-generated schematics on a peculiar overdischarge phenomenon was conducted to understand cell behavior against overdischarge protection. It is useful to characterize such overdischarge events to understand the impacts of such variations on battery control and management during the operation of battery packs. The understanding shall shed some light on the particular events and their effects with regard to the consequences on reliability and safety of the battery system. Eventually, it would be desirable that various degrees of overdischarge be characterized, as similar overdischarge events may occur in cells in a string or battery pack where intrinsic cell variability, extrinsically induced imbalance, and variations in the operating conditions such as under temperature gradients may present in a system. Although this particular overdischarge phenomenon may only be relevant to this c-PE cell design and chemistry, this mechanistic study shall address the general concern of possible overdischarging events in composite electrode design and performance and their consequence in capacity fade with composite electrode designs.To receive a comprehensive understanding of this overdischarging behavior in the c-PE, one should refer to early studies of this family of materials, particularly th...

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“…According to the different combination modes between the LL and spinel, the LLS materials can be divided into three categories including mechanical mixing, core–shell, and fully integrated. First, mechanical mixing LL with Fd

\overset{3}{true}

m spinels is a straightforward method to prepare LLS . However, samples prepared from this method lack interconnection between the two components, so their overall performance only reflects as average of each phase.…”

Section: Libsmentioning

confidence: 99%

Layer‐Based Heterostructured Cathodes for Lithium‐Ion and Sodium‐Ion Batteries

Deng

Liang

et al. 2019

Adv Funct Materials

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A critical bottleneck that hinders major performance improvement in lithium-ion and sodium-ion batteries is the inferior electrochemical activity of their cathode materials. While significant research progresses have been made, conventional single-phase cathodes are still limited by intrinsic deficiencies such as low reversible capacity, enormous initial capacity loss, rapid capacity decay, and poor rate capability. In the past decade, layer-based heterostructured cathodes acquired by combining multiple crystalline phases have emerged as candidates with a huge potential to realize performance breakthrough. Herein, recent studies on the structural properties, electrochemical behaviors, and synthesis route optimizations of these heterostructured cathodes are summarized for in-depth discussions. Particular attention is paid to the latest mechanism discoveries and performance achievements. This review thus aims to promote a deeper understanding of the correlation between the crystal structure of cathodes and their electrochemical behavior, and offers guidance to design advance cathode materials from the aspect of crystal structure engineering.

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Electrochemical studies on cathode blends of LiMn2O4 and Li[Li1/15Ni1/5Co2/5Mn1/3O2]

Cited by 46 publications

References 31 publications

Investigations on the Effective Electric Loads in Blended Insertion Electrodes for Lithium‐Ion Batteries

Investigations on the Effective Electric Loads in Blended Insertion Electrodes for Lithium‐Ion Batteries

Evaluation of Commercial Lithium-Ion Cells Based on Composite Positive Electrode for Plug-In Hybrid Electric Vehicle (PHEV) Applications

Layer‐Based Heterostructured Cathodes for Lithium‐Ion and Sodium‐Ion Batteries

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