Influence of Temperature on the Interface Chemistry of LixMn2O4 Electrodes

Eriksson, Therése; Andersson, A.M; Gejke, Cecilia; Gustafsson, Torbjörn; Thomas, John O.

doi:10.1021/la011354m

Cited by 92 publications

(120 citation statements)

References 57 publications

Supporting

Mentioning

114

Contrasting

Order By: Relevance

“…[26][27][28] This is consistent with observations made on the basis of the O 1s region in Figure 3 and the P 2p region in Figure 5, where the cycled positive electrodes contain O and P contributions, respectively, from Li x PF y O z . In addition, Figure 5 displays a P contribution, which corresponds to LiPF 6 .…”

Section: F 1s and P 2p Regions-as Shown Insupporting

confidence: 80%

Probing the Electrode-Electrolyte Interface in Cycled LiNi_0.5Mn_1.5O₄by XPS Using Mg and Synchrotron X-rays

Mansour

Kwabi

Quinlan

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

X-ray photoelectron spectroscopy (XPS) was used to investigate the surface chemistry of high voltage spinel, LiNi 0.5 Mn 1.5 O 4 (LNMO) positive electrodes cycled 5 and 10 times in Li-cells with 1 M LiPF 6 in (3:7) EC:DMC. The XPS spectra were collected using conventional Mg X-rays with energy of 1253.6 eV as well as synchrotron X-rays with energies of 2493.6 and 3498.4 eV in order to examine the depth distribution of various surface chemical species induced during cycling. The XPS spectra revealed a 5 -10 nm surface layer of organic and Li x PF y O z -type species formed as result of electrolyte decomposition, and a comparatively thinner layer composed of transition metal fluorides and LiF. These results suggest that electrolyte decomposition is a major contributor to parasitic reactions in LNMO battery electrochemistry. Limiting electrolyte decomposition with the use of solvents with wide electrochemical stability windows thus comprises a promising strategy for ensuring the practical feasibility of high voltage spinel materials in future Li-ion systems. Rechargeable lithium-ion batteries (LIBs) are among the widest used energy sources for portable electronic devices, but are currently being considered for more energy-dense applications such as electric vehicles and short-term grid support. In order to realize these possibilities, gravimetric energy densities of typical LIBs, which currently provide 400-550 Wh/kg need to be improved. LiNi 0.5 Mn 1.5 O 4 (LNMO) is a particularly promising positive electrode material in this regard, as it operates at an exceptionally high voltage of 4.8 V vs Li + /Li, 1 resulting in an energy density of ∼706 Wh/kg based on a theoretical capacity of 147 mAh/g for 1e − transfer. 2 Such a high voltage is however above the potential at which most LIB electrodes, cell components and electrolytes decompose (>4.2 V vs Li + /Li), and results in the formation of highly resistive parasitic species that hamper battery reversibility and cycle life.In order to design LIBs that are chemically stable enough for practical application, a strong fundamental understanding of electrolyte decomposition and side product formation mechanisms is required. In positive LIB electrodes, battery cycling typically results in an electrode-electrolyte interface (EEI), the study of which can yield mechanistic insights into particularly critical parasitic reaction pathways responsible for poor electrochemical performance.3 Thus, understanding the structure and composition of the surface EEI in LNMObased positive electrodes is key to their commercial realization.Previous studies exploring LNMO performance degradation during cycling have explored the influence of stoichiometry, 4 cation ordering, 4,5 doping 6 and particle morphology. 5,7,8 There have been relatively fewer studies exploring EEI formation in detail, likely owing to the difficulty of characterizing thin layers (typically < 20 nm) of product. Using Raman and Electrochemical Impedance Spectroscopy (EIS) measurements, Aurbach et al. 9 suggested that LNMO...

show abstract

Section: F 1s and P 2p Regions-as Shown Insupporting

confidence: 80%

Probing the Electrode-Electrolyte Interface in Cycled LiNi_0.5Mn_1.5O₄by XPS Using Mg and Synchrotron X-rays

Mansour

Kwabi

Quinlan

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…Fig. 7a presents impedance spectra (Nyquist plots) measured after the initial Li intercalation into the MCMB + MCF anode (1) and after the first deintercalation process (2). The drastic shrinkage of the high frequency semicircle of these spectra after deintercalation during initial cycling of graphite electrodes, has already been described [24,25].…”

Section: Resultsmentioning

confidence: 95%

“…It is known that the stability of Li-ion cells degrades when they are exposed to or operated at temperatures above 60 • C [1][2][3]. There is a variety of cathode and anode material combi- * Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

On the performance of graphitized meso carbon microbeads (MCMB)–meso carbon fibers (MCF) and synthetic graphite electrodes at elevated temperatures

Markevich

Pollak

Salitra

et al. 2007

Journal of Power Sources

View full text Add to dashboard Cite

“…For example, in F 1s spectra, peaks of LiF (685 eV) and Li x PO y F z (686.8 eV) resulting from salt reduction products were observed for the cycled cathode surface. 7,17,18 Peaks of LiF (55.7 eV), Li x PO y F z (56.7 eV), and Li 2 CO 3 (55.1 eV) were observed in Li 1s spectra for the cycled NMC532 surface. In C 1s spectra, the small peak representing CF 3 (293 eV) was observed only for the FEC/FEMC (1/9) system.…”

Section: Resultsmentioning

confidence: 96%

Fluorinated Carbonate-Based Electrolyte for High-Voltage Li(Ni_0.5Mn_0.3Co_0.2)O₂/Graphite Lithium-Ion Battery

Lee

Ryou

et al. 2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

A stable electrolyte system at a charge voltage over 4.5 V is the key to successfully obtaining higher energy density by raising the charging cutoff voltage. We demonstrate a fluorinated electrolyte (1 M LiPF 6 fluoroethylene carbonate (FEC) and methyl (2,2,2-trifluoroethyl) carbonate (FEMC) (FEC/FEMC = 1/9, v/v)) for a high-voltage LiNi 0.5 Mn 0.3 Co 0.2 O 2 /graphite system. The stability of the fluorinated electrolyte for the LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532) cathode was investigated using scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. The charge-discharge performance of the fluorinated electrolyte was superior to the corresponding non-fluorinated electrolyte system at a charging cutoff voltage of 4. Considerable efforts have been made for developing high-charge voltage platforms that provide large capacities, thereby helping improve the energy density of lithium-ion batteries (LIB). Because electrical energy is the product of the discharge capacity and the average discharge voltage, it is important to search for cathode materials with a high discharge voltage.1 To this end, many studies have been devoted to improving cathode materials for high-voltage applications, such as polyanion oxides (LiCoPO 4 ), spinel-type oxides (LiMn 2 O 4 ), and layered oxides (LiNi x Mn y Co 1-x-y O 2 ). Among cathode materials, LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532) is one of the most promising for its potential practical application in high-voltage lithium-ion battery. 2-4However, there remains a critical obstacle that should be overcome for high-voltage lithium-ion batteries. Oxidative instability of the conventional non-aqueous electrolyte takes place at a charging voltage beyond 4.5 V, leading to severe decay of cycling performances.5 Per research, practical approaches to improving performance for highvoltage operation include use of a new solvent or introducing functional additives to the electrolyte. [6][7][8] Recently, incorporation of the fluorinated compound either as solvent or as additive have been investigated for high-voltage LIB and positive effects have been reported. [9][10][11][12][13] Especially, utilization of fluoroethylene carbonate (FEC), which is well known to form solid-electrolyte interphase (SEI) on the anode surface with the small amounts addition, in high-voltage LIB has gathered attention. Based on 1 M LiPF 6 ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (EC/EMC = 3/7, wt/wt) electrolyte, FEC was used as a fluorinated solvent (20∼50%) to replace EC or as a fluorinated additive (>5%) in a base electrolyte solution. However, there are a few studies reported on the electrolyte system consisting of wholly fluorinated solvents and additive. Here, we demonstrate a fully fluorinated electrolyte system composed of FEC and methyl (2,2,2-trifluoroethyl) carbonate (FEMC) at a volume ratio of 1:9 for high-voltage lithium-ion batteries. Amount of FEC is selected slightly higher than the case of FEC as additive in base solvent and much lower th...

show abstract

Influence of Temperature on the Interface Chemistry of Li_xMn₂O₄ Electrodes

Cited by 92 publications

References 57 publications

Probing the Electrode-Electrolyte Interface in Cycled LiNi_0.5Mn_1.5O₄by XPS Using Mg and Synchrotron X-rays

Probing the Electrode-Electrolyte Interface in Cycled LiNi_0.5Mn_1.5O₄by XPS Using Mg and Synchrotron X-rays

On the performance of graphitized meso carbon microbeads (MCMB)–meso carbon fibers (MCF) and synthetic graphite electrodes at elevated temperatures

Fluorinated Carbonate-Based Electrolyte for High-Voltage Li(Ni_0.5Mn_0.3Co_0.2)O₂/Graphite Lithium-Ion Battery

Contact Info

Product

Resources

About

Influence of Temperature on the Interface Chemistry of LixMn2O4 Electrodes

Cited by 92 publications

References 57 publications

Probing the Electrode-Electrolyte Interface in Cycled LiNi0.5Mn1.5O4by XPS Using Mg and Synchrotron X-rays

Probing the Electrode-Electrolyte Interface in Cycled LiNi0.5Mn1.5O4by XPS Using Mg and Synchrotron X-rays

On the performance of graphitized meso carbon microbeads (MCMB)–meso carbon fibers (MCF) and synthetic graphite electrodes at elevated temperatures

Fluorinated Carbonate-Based Electrolyte for High-Voltage Li(Ni0.5Mn0.3Co0.2)O2/Graphite Lithium-Ion Battery

Contact Info

Product

Resources

About

Influence of Temperature on the Interface Chemistry of Li_xMn₂O₄ Electrodes

Probing the Electrode-Electrolyte Interface in Cycled LiNi_0.5Mn_1.5O₄by XPS Using Mg and Synchrotron X-rays

Probing the Electrode-Electrolyte Interface in Cycled LiNi_0.5Mn_1.5O₄by XPS Using Mg and Synchrotron X-rays

Fluorinated Carbonate-Based Electrolyte for High-Voltage Li(Ni_0.5Mn_0.3Co_0.2)O₂/Graphite Lithium-Ion Battery