Low temperature electrolytes for Li-ion PVDF cells

Shiao, H. C.; Chua, D. L.; Lin, Hsiu-ping; Slane, S.; Salomon, Mark

doi:10.1016/s0378-7753(99)00470-x

Cited by 150 publications

(82 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The working temperature range of a lithium-ion battery is limited to −10 to 40°C [5,8]. Many works have been done to enable the cell to operate at temperatures less than or equal to −30°C [9][10][11][12][13]. Sazhin et al have already studied the effect of adding ethyl propionate to electrolytes such as 1 M LiPF 6 /EC-DEC and 1 M LiPF 6 /EC-EMC where EMC is ethyl methyl carbonate.…”

Section: Introductionmentioning

confidence: 99%

Performance of lithium-ion cells using 1 M LiPF6 in EC/DEC (v/v = 1/2) electrolyte with ethyl propionate additive

Kufian

Majid

2009

Ionics

View full text Add to dashboard Cite

In this work, 1 M LiPF 6 :EC:DEC (v/v=1/2) was used as a baseline electrolyte where EC is ethylene carbonate and DEC is diethyl carbonate. Ethyl propionate (EP) was used as an additive. The conductivity of the liquid electrolyte was obtained at ambient and elevated temperatures. The highest room temperature conductivity was observed at (8.05±0.16)mS cm −1 for the electrolyte containing 28.6 vol.% EP. Viscosity of the baseline and EP added baseline electrolytes have been measured at room and elevated temperatures. The electrolyte was also characterized by linear sweep voltammetry. The highest conducting electrolyte with 28.6 vol.% EP and the baseline electrolyte were used to fabricate several batteries. The batteries were charged and discharged at room temperature and at −20°C.

show abstract

Section: Introductionmentioning

confidence: 99%

Performance of lithium-ion cells using 1 M LiPF6 in EC/DEC (v/v = 1/2) electrolyte with ethyl propionate additive

Kufian

Majid

2009

Ionics

View full text Add to dashboard Cite

show abstract

“…Esters have been applied to improve the low temperature rate capability of Liion cells and also improve rate capability at room temperature. [3][4][5][6][7][8][9][10] Li-ion batteries with esters and positive electrodes of LiCoO 2 were studied in References 4-7 while those with LiNi x Co 1-x O 2 positive electrodes were studied by Smart et al lifetime with an electrolyte containing 2 wt% prop-1-ene-1,3 sultone (PES) + 1 wt% tris (trimethylsilyl) phosphite (TTSPi) + 1 wt % ethylene sulfate (DTD) in 1 M LiPF 6 in ethylene carbonate (EC): ethyl methyl carbonate (EMC) (3:7 by weight). More than 92% capacity was maintained after testing for one year between 3.0 and 4.4 V (∼1600 cycles with C/2 rate, CCCV) at 40…”

mentioning

confidence: 99%

Methyl Acetate as a Co-Solvent in NMC532/Graphite Cells

et al. 2018

J. Electrochem. Soc.

View full text Add to dashboard Cite

One goal of researchers focusing on lithium-ion batteries for electric vehicles is to decrease the time required for charging. This can be done by several methods, including increasing the electrolyte transport properties. Methyl acetate, used as a co-solvent in the electrolyte, has been shown by a number of researchers to increase cell rate capability dramatically but careful considerations of the impact of methyl acetate on cell lifetime have not been published to our knowledge. The impacts of methyl acetate as a co-solvent in NMC532/ graphite cells were systematically studied in this work. Ex-situ gas evolution measurements, electrochemical impedance spectroscopy, high rate charging tests, ultra-high precision coulometry, isothermal microcalorimetry and long term cycling at both 20 and 40 • C were used to probe the impacts of including methyl acetate as a co-solvent. This work will be of great interest to Li-ion battery scientists developing cells that can support rapid charge and still maintain long lifetime. Lithium ion cells for electric vehicles should have long lifetime, high energy density and be able to support high rate charging. If cells are charged too rapidly for a given temperature, it is possible that unwanted lithium plating on the graphite negative electrode can occur and can accelerate cell capacity loss.1 There are a number of factors that influence the ability of cells to be charged rapidly. These include the thicknesses of the electrodes and the separator, the porosity and tortuosity of the electrodes and the separator and the electrolyte transport properties. In addition, Liu et al.,2 recently highlighted the importance of the negative electrode solid electrolyte interphase (SEI) resistance on the ability of cells to be charged rapidly without unwanted lithium plating during charge.For any given cell design, the easiest change to make in Liion cell manufacturing is a change in the electrolyte. All that entails, apart from possible materials compatibility issues, is filling cells with a different fluid. Electrolytes that promote high lithiumion diffusion constants, low viscosity, high conductivity, a high lithium ion transference number and promote low resistance negative electrode SEI layers are preferred for cells designed for high rate charging. Esters are beneficial co-solvents that lower freezing points, increase ionic conductivity and lower viscosity. Esters have been applied to improve the low temperature rate capability of Liion cells and also improve rate capability at room temperature. [3][4][5][6][7][8][9][10] Li-ion batteries with esters and positive electrodes of LiCoO 2 were studied in References 4-7 while those with LiNi x Co 1-x O 2 positive electrodes were studied by Smart et al. lifetime with an electrolyte containing 2 wt% prop-1-ene-1,3 sultone (PES) + 1 wt% tris (trimethylsilyl) phosphite (TTSPi) + 1 wt % ethylene sulfate (DTD) in 1 M LiPF 6 in ethylene carbonate (EC): ethyl methyl carbonate (EMC) (3:7 by weight). More than 92% capacity was maintained after testing for ...

show abstract

“…EA has been reported to be highly reactive to the negative electrode. 4,5 The results in Figure 5 suggest that MP shows mild reactivity at both the positive and negative electrodes while EA is more reactive at the charged positive electrode. Figure 6 compares the gas produced in NCA cells containing the three esters after formation (Figure 6a), after 4.2 V storage ( Figure 6b) and after 2.5 V storage (Figure 6c), respectively.…”

Section: Resultsmentioning

confidence: 99%

“…EA) performed well initially but degraded during longterm cycling due to high reactivity with the negative electrode. 4,5 The most studied positive electrode materials in combination with esters in Li-ion batteries were LiCoO 2 5-8 and LiNi x Co 1-x O 2 , and the latter was mainly studied by Smart et al 4,9 In our group, EA and MP used as a sole electrolyte solvent have been studied in Li [ 13,14 Large fractions of esters are now appearing in commercial lithium-ion cells. For example we have performed analysis on some LiCoO 2 /graphite Li-ion cells, rated for 4.35 V, and found an electrolyte that was LiPF 6 dissolved in MP:FEC:PC in ratios of 56:37:7 by weight.…”

mentioning

confidence: 99%

A Study of Three Ester Co-Solvents in Lithium-Ion Cells

Arumugam

et al. 2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

The effects of three esters incorporated as co-solvents in 1.2 M LiPF 6 EC:EMC:DMC (25:5:70 by volume %) electrolyte were studied in Li[Ni 1-x-y Co x Al y ]O 2 /Graphite-SiO pouch cells. The esters: methyl propionate (MP), ethyl acetate (EA) and methyl butyrate (MB) were compared in a variety of tests on the cells. Storage tests at 60 • C at both 4.2 V and 2.5 V demonstrated that MB and MP outperformed EA and cells containing 20% MP showed the least voltage drop during the 500 h storage period. In long-term cycling tests at 40 • C, cells containing up to 20% ester exhibited similar capacity retention compared to cells with only EC:EMC:DMC solvent. Unwanted lithium plating could be suppressed in cells with 20% MP during charging above 2C compared to ester-free cells, which showed the onset of unwanted lithium plating at 1.8C. This improvement is due to the increased Li + conductivity of electrolytes containing MP. In addition, the use of up to 40% MP did not enhance reactivity between the charged electrode materials and electrolyte at elevated temperatures according to accelerating rate calorimetry measurements. To further satisfy the development of electric vehicles (EVs), Liion batteries need to be designed with higher volumetric energy density, longer cycling life, higher rate capability, lower cost and so forth. These improvements can be fully or partially achieved by applying new positive and/or negative electrode materials, suitable electrolytes and additives. For instance, Li[Ni 0.85 Co 0.10 Al 0.05 ]O 2 (NCA), as a typical positive electrode material, exhibits high energy density and capacity, and has been used in many EVs 1,2 and power tools. Esters are beneficial co-solvents that can improve the physical properties of carbonate-based electrolytes due to their low freezing points, high ionic conductivity of the resulting electrolytes and low viscosity. Esters have been mainly studied for the low temperature application of Li-ion cells, and compounds of interest include, ethyl acetate (EA), methyl butyrate (MB), ethyl butyrate (EB), methyl propionate (MP), ethyl propionate (EP), etc.4-12 Of these ester solvents, it has been reported that those with low molecular weight (e.g. EA) performed well initially but degraded during longterm cycling due to high reactivity with the negative electrode. 4,5 The most studied positive electrode materials in combination with esters in Li-ion batteries were LiCoO 2 5-8 and LiNi x Co 1-x O 2 , and the latter was mainly studied by Smart et al. 4,9 In our group, EA and MP used as a sole electrolyte solvent have been studied in Li [Ni 0.33 Large fractions of esters are now appearing in commercial lithium-ion cells. For example we have performed analysis on some LiCoO 2 /graphite Li-ion cells, rated for 4.35 V, and found an electrolyte that was LiPF 6 dissolved in MP:FEC:PC in ratios of 56:37:7 by weight. Presumably this novel electrolyte system was selected to improve high voltage performance and improve rate capability. It is important to determine if MP would be the best...

show abstract

Low temperature electrolytes for Li-ion PVDF cells

Cited by 150 publications

References 9 publications

Performance of lithium-ion cells using 1 M LiPF6 in EC/DEC (v/v = 1/2) electrolyte with ethyl propionate additive

Performance of lithium-ion cells using 1 M LiPF6 in EC/DEC (v/v = 1/2) electrolyte with ethyl propionate additive

Methyl Acetate as a Co-Solvent in NMC532/Graphite Cells

A Study of Three Ester Co-Solvents in Lithium-Ion Cells

Contact Info

Product

Resources

About