Study of Deposition and Dissolution Processes of Lithium in Carbonate‐Based Solutions by Means of the Quartz‐Crystal Microbalance

Naoi, Katsuhiko; Mori, Mitsuhiro; Shinagawa, Yukio

doi:10.1149/1.1837040

Cited by 47 publications

(38 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results indicate that the NMC-Li-metal cell displays a large hysteresis (overpotential) over long term cycling, but the NMC-LTO and NMC-graphite cells show a stable and small overpotential. Note that the overpotential in the NMC-Li-metal cell decreases during the initial cycling, which could be explained by roughening of the surface of Li-metal providing higher surface area and lower resistance, 20 however, the overpotential increases rapidly during the continued cycling. As the NMC cathodes are cycled against different types of anodes, the differences in overpotential is assumed to be caused by the choice of the anode.…”

Section: Resultsmentioning

confidence: 99%

How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi_1/3Co_1/3Mn_1/3O₂Cathodes in Li-Ion Batteries

Björklund

Brandell

Hahlin

et al. 2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

The cycle life of LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NMC) based cells are significantly influenced by the choice of the negative electrode. Electrochemical testing and post mortem surface analysis are here used to investigate NMC electrodes cycled vs. either Li-metal, graphite or Li 4 Ti 5 O 12 (LTO) as negative electrodes. While NMC-LTO and NMC-graphite cells show small capacity fading over 200 cycles, NMC-Li-metal cell suffers from rapid capacity fading accompanied with an increased voltage hysteresis despite the almost unlimited access of lithium. X-ray absorption near edge structure (XANES) results show that no structural degradation occurs on the positive electrode even after >200 cycles, however, X-ray photoelectron spectroscopy (XPS) results shows that the composition of the surface layer formed on the NMC cathode in the NMC-Li-metal cell is largely different from that of the other NMC cathodes (cycled in the NMC-graphite or NMC-LTO cells). Furthermore, it is shown that the surface layer thickness on NMC increases with the number of cycles, caused by continuous electrolyte degradation products formed at the Li-metal negative electrode and then transferred to NMC positive electrode. Li-ion batteries (LiBs) are widely used in applications where rechargeability of high energy density storage units is required, such as portable devices including consumer electronics, vehicles and space applications. It is beneficial that the components are as light-weight as possible for portable devices, thereby decreasing the energy required to transport the device. One widely used positive electrode material contributing to high energy density is LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NMC), either operating at a higher potential or having a larger practical specific capacity than the classical LiMn 2 O 4 and LiFePO 4 materials.1,2 NMC is also less costly than the LiCoO 2 alternative due to the decreased cobalt content.In commercial cells, NMC electrodes are most often cycled vs. graphite negative electrodes which has a low working potential, enabling a large potential difference between the electrodes. However, the low working potential is outside of the electrochemical stability window of most common electrolytes, leading to formation of a solid electrolyte interphase (SEI) layer on the anode surface. A corresponding but thinner layer could also form on the side of the positive electrode depending on the working potential of the cathode. 3,4 Lithium is consumed during SEI formation, which results in a decrease in the cell capacity and an increase in the cell resistance. The problems caused by SEI layer formation can be resolved by changing the negative electrode to an electrode working at a higher potential -within the electrochemical stability window of the electrolytesuch as lithium titanate (Li 4 Ti 5 O 12 ; LTO). Although the increased working potential decreases the energy density of the cell, cycle life is generally increased. The Li-metal anode is another negative electrode that is commonly used as counter/reference electrode, at le...

show abstract

Section: Resultsmentioning

confidence: 99%

How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi_1/3Co_1/3Mn_1/3O₂Cathodes in Li-Ion Batteries

Björklund

Brandell

Hahlin

et al. 2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…26,27,36,37 Because ⌬f has been confirmed to be largely responsible for a mass change, 27 ⌬f irr represents the irreversible change in ⌬f at one deposition-dissolution cycle corresponding to the amount of the accumulated surface film. Figure 6 shows ⌬f irr vs. cycle number plots for Li-BETI/PC in comparison with LiPF 6 /PC, LiTFSI/PC, and LiOSO 2 CF 3 /PC.…”

Section: Region a (Thickness: < Ca 1 Nm)-inmentioning

confidence: 99%

“…We also confirmed that the high reactivity of PF 6 Ϫ anions induces the formation of LiF and has the ability to inhibit the decomposition of PC. 26,47 Because Li-BETI has very good thermal and chemical stability compared to the PF 6 Ϫ anion, 23 the chemical reactions such as 3 do not occur in the presence of BETI anions, and the formation of LiF derived via. HF (reactions 7,8,9) would not take place at the electrode surface.…”

Section: Region a (Thickness: < Ca 1 Nm)-inmentioning

confidence: 99%

The Surface Film Formed on a Lithium Metal Electrode in a New Imide Electrolyte, Lithium Bis(perfluoroethylsulfonylimide) [ LiN ( C 2 F 5 SO 2 ) 2 ]

Naoi

Mori

Naruoka

et al. 1999

J. Electrochem. Soc.

Self Cite

112

View full text Add to dashboard Cite

In order to enhance the performance of Li or Li-ion batteries many kinds of electrolytes have been studied and developed over the years. 1,2 These electrolytes are needed to give optimum interfacial properties between the electrolyte and the various anodes or cathodes. So far, the salts such as LiClO 4 , LiPF 6 , LiBF 4 , LiAsF 6 , and LiOSO 2 CF 3 . LiOSO 2 CF 3 have been used in these batteries. However, there are advantages and disadvantages with each salt. These salts typically do not provide a balance of desired properties such as high ionic conductivity, high chemical/thermal stability, low toxicity, and a wide potential window. For example, LiClO 4 can induce explosions under some conditions. 3,4 LiPF 6 and LiBF 4 have poor chemical/thermal stability. 5-7 LiAsF 6 is regarded as one of the best salts because it gives the highest coulombic efficiency, but it degrades into toxic products. 8-12 LiOSO 2 CF 3 , which is more stable and safer than other salts, has the disadvantage of low ionic conductivity and like LiTFSI is corrosive toward Al current collectors at high potentials. 1 Due to its good ionic conductivity, electrochemical stability and low corrosion of Al, LiPF 6 is often used as the preferred salt in Li-ion rechargeable batteries.Recently, lithium bis(trifluoromethylsulfonylimide) [LiN(CF 3 SO 2 ) 2 , (HQ-115, available from 3M Company) LiTFSI] was introduced as a salt which acts as a good plasticizer for polyethylene oxide (PEO) electrolytes. [13][14][15] For application in polymer electrolyte systems, LiTFSI-PEO complexes exhibit rather low crystallinity and a low glass transition temperature (T g ), resulting in ionic conductivity above 10 Ϫ6 S cm Ϫ1 at 25ЊC. 14 The ionic conductivity of LiTFSI in propylene carbonate (PC) solvent is also comparable to that of LiPF 6 . Furthermore, this kind of imide salt has good chemical stability and safety characteristics. 13-15 Because of the above advantages of LiTFSI, several studies have been made of LiTFSI-based electrolytes. [16][17][18][19][20][21][22] However, the practical use of this salt in liquid electrolytes has not materialized due to its severe corrosion of Al which is commonly used as a cathode current collector above 3.6 V vs. Li/Li ϩ . 23 Very recently, a new imide salt, lithium bis(perfluoroethylsulfonylimide) [LiN(SO 2 C 2 F 5 ) 2 , Li-BETI] was introduced, in which the perfluoroalkyl groups are extended from -CF 3 (TFSI anion) to -C 2 F 5 (BETI anion). 23 Li-BETI has a relatively high ionic conductivity (ca. 10 mS cm Ϫ1 ) at a concentration of 1 mol dm Ϫ3 (ϭM) in PC:1,2-dimethoxyethane (DME) (1:1), and has excellent thermal stability up to 340ЊC compared to that of LiPF 6 , which undergoes thermal decomposition between 60 and 100ЊC. The relatively high ionic conductivity of Li-BETI/PC ϩ DME electrolyte can be attributed to the remarkable delocalization of charge in this molecule (see Fig. 1). 13 Compared to LiTFSI, Li-BETI offers a further advantage of improved corrosion performance with a repassivation potential of 4.2 V vs. Li/Li ϩ . 2,...

show abstract

“…At a more negative potential than These results indicated that the competition reaction for Nd(III)/Nd(0) reduction and IL decomposition would occur and depend on the Nd(III) concentration. The value of ηρ after 0.45 C cm −2 increased and the IL decomposition was also deduced from this result because the ηρ change implied that the quantity of the soluble species increase near the electrode and/or the viscoelastic film might be formed on the electrode surface [27,31,32,40] by the IL decomposition.…”

Section: Electrochemical Analysismentioning

confidence: 70%

Purification of Rare Earth Amide Salts by Hydrometallurgy and Electrodeposition of Rare Earth Metals Using Ionic Liquids

Matsumiya¹

2017

Progress and Developments in Ionic Liquids

View full text Add to dashboard Cite

This paper reports a novel bench-scale hydrometallurgical procedure and electrodeposition using triethyl-pentyl-phosphonium bis(trifluoromethyl-sulfonyl)amide ([P 2225 ][TFSA]) ionic liquids (ILs) for the recovery of rare earth (RE) metals from spent Nd-Fe-B magnets. The hydrometallurgical treatments were carried out at bench scale to produce RE amide salts of high purity. In the leaching process employing 1.7 kg of oxidized Nd-Fe-B fine powder and 14.2 L of an acid medium of 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide (H[TFSA]), selective leaching of RE ions (85.7±5.8% Nd) was performed at bench scale. Then, Fe (<99.9%) was successfully separated from RE ions in the deironization process. The total amount of the recovered amide salts through the evaporation treatment using a spray dryer was 3.57 kg. From the CV/EQCM measurements for Nd(III) at 373 K, a clear cathodic peak with the mass increased, and the ηρ decreased was observed at −2.79 V. Considering our previous investigations, the reduction of Nd(III)/Nd(0) was indicated as [Nd (III) (TFSA) 5 ] 2− + 3e − → Nd(0) + 5[TFSA] − . In addition, the M app value in the range of −2.49 V ~ −2.94 V was 46.8 g mol −1 , which was close to the theoretical value for the electrodeposition reaction of Nd(III)/Nd(0), 48.1 g mol −1 . Moreover, the electrodeposition of Nd(0) was carried out under the condition of −3.20 V versus Fc/Fc + at 373 K. The electrodeposits were identified with the metallic Nd in the middle layer investigated by X-ray diffraction and X-ray photoelectron spectroscopy. Finally, we demonstrated that the novel recovery process consisted of hydrometallurgy and electrodeposition using ILs was effective by calculating material flow.

show abstract

Study of Deposition and Dissolution Processes of Lithium in Carbonate‐Based Solutions by Means of the Quartz‐Crystal Microbalance

Cited by 47 publications

References 0 publications

How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi_1/3Co_1/3Mn_1/3O₂Cathodes in Li-Ion Batteries

How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi_1/3Co_1/3Mn_1/3O₂Cathodes in Li-Ion Batteries

The Surface Film Formed on a Lithium Metal Electrode in a New Imide Electrolyte, Lithium Bis(perfluoroethylsulfonylimide) [ LiN ( C 2 F 5 SO 2 ) 2 ]

Purification of Rare Earth Amide Salts by Hydrometallurgy and Electrodeposition of Rare Earth Metals Using Ionic Liquids

Contact Info

Product

Resources

About

Study of Deposition and Dissolution Processes of Lithium in Carbonate‐Based Solutions by Means of the Quartz‐Crystal Microbalance

Cited by 47 publications

References 0 publications

How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi1/3Co1/3Mn1/3O2Cathodes in Li-Ion Batteries

How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi1/3Co1/3Mn1/3O2Cathodes in Li-Ion Batteries

The Surface Film Formed on a Lithium Metal Electrode in a New Imide Electrolyte, Lithium Bis(perfluoroethylsulfonylimide) [ LiN ( C 2 F 5 SO 2 ) 2 ]

Purification of Rare Earth Amide Salts by Hydrometallurgy and Electrodeposition of Rare Earth Metals Using Ionic Liquids

Contact Info

Product

Resources

About

How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi_1/3Co_1/3Mn_1/3O₂Cathodes in Li-Ion Batteries

How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi_1/3Co_1/3Mn_1/3O₂Cathodes in Li-Ion Batteries