Electrochemical impedance spectroscopy study of the SEI formation on graphite and metal electrodes

A theoretical equivalent circuit model of two 40Ah commercial batteries supplied by Saft was formulated to interpret electrochemical impedance spectra as a function of temperature at zero state-of-charge. The batteries were chosen to represent viable and non-viable products from the Saft production line. This paper is the first contribution from a project in Newcastle to develop a rapid, non-destructive analytical method for quality control on the battery production line. Using the model, it proved straightforward to discriminate between viable and non-viable batteries based on the temperature dependence of the electrochemical reaction kinetics at the electrodes, the average diffusion coefficients and the charge transfer resistances. Furthermore, as well as marked differences, for example, between the time constants, activation energies, polarisation resistances of the viable and non-viable batteries, the individual contributions of the anodes and cathodes in the batteries were de-convoluted and interpreted through the model framework.5

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“…5. As may be seen from the figure, for battery 2, there is a linear variation in agreement with Arrhenius behaviour [38], according to:…”

Section: Resultssupporting

confidence: 71%

A study of 40 Ah lithium ion batteries at zero percent state of charge as a function of temperature

Attidekou

Lambert

Armstrong

et al. 2014

Journal of Power Sources

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“…Among other effects, a passivated cathode would show a lower leakage current toward the end of the potentiostatic hold, indicating a decrease in the rate of electrolyte oxidation. This protocol should be resistant to other methods of performance improvement, including changes to the anode SEI, as kinetic inhibition of electrochemical reduction is not necessary with LTO, 37,38 as well as transition metal ion dissolution and migration to the anode SEI. 39,40 ) unless CC License in place (see abstract With this protocol, we can determine if the oxidation decomposition of an additive molecule passivates the cathode surface.…”

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confidence: 99%

The Role of Additives in Improving Performance in High Voltage Lithium-Ion Batteries with Potentiostatic Holds

Tornheim

et al. 2017

J. Electrochem. Soc.

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In this work, various electrolyte additives designed for enhanced performance at high voltages were evaluated with elevated temperature potentiostatic holds with LiNi 0.5 Co 0.2 Mn 0.3 /Li 4 Ti 5 O 12 full cells to determine their effect on the high voltage stability. Of the additives investigated, many showed increased oxidation current through the 60 hour potentiostatic holds test, and adversely affected both the capacity retention and interfacial impedance. Improved high voltage performance was observed with two additives, vinylene carbonate (VC) and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), which was attributed to two different mechanisms of improvement. This work investigates some conclusions in the available literature of an additive molecule that decomposes on the charged cathode surface and passivates the surface against electrolyte oxidation. With the goal of increasing battery energy density for transportation applications, layered transition metal oxides cathodes of the form LiMO 2 (M = Ni, Co, Mn) have received significant attention.1-7 While these cathode materials have a high theoretical gravimetric capacity of ∼280 mAh/g, 8 achieving the high capacity of these materials requires very high charging voltages (>4.5V vs. Li + /Li), 2-4 above the stability range of conventional carbonate electrolytes.9,10 Enabling the additional high voltage capacity of the cathode materials requires new electrolytes that provide additional stability at high voltages at the charged cathode surface.The approach to creating compatible electrolytes has mainly fallen along two separate paths: either increasing the intrinsic anodic stability of the electrolyte, [11][12][13][14][15][16][17] or using a sacrificial component in small amounts (an additive) to "passivate" the cathode surface and inhibit continual electrolyte oxidation.18 20,32 have shown evidence of decomposition on various high voltage cathode surfaces through a variety of surface characterization techniques, including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS).However, this cathode "passivation" is conventionally inferred through a combination of experimental results, such as increased capacity retention, voltammetric methods indicating a lower anodic stability attributed to additive oxidation, changes to the XPS and/or FTIR spectra of the cathode that include components of the additive, and decreased impedance after cycling. While the results provided by the previously mentioned characterization methods can be reconciled with the conclusion that cathode "passivation" led to the improvement, this mechanistic process can be more accurately evaluated by monitoring the electrolyte oxidation current at a charged cathode surface through potentiostatic holds. A passivation layer will limit electron transfer from the electrolyte to the charged cathode surface. By this definition, this layer must have both a minimal electron conductivity as well as a minimal diffusio...

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“…11,[19][20][21][22][23][24][25] However, with increasing demands on the electrolyte regarding thermal and/or electrochemical stability, the limitations of such electrolyte mixtures are unraveled. 11,26,27 Alternative electrolyte compositions that depict certain improvements compared to the state-of-the-art electrolyte are still required to fulfil the following properties: a sufficient ionic conductivity to transport the lithium ions, the ability to form an effective solid electrolyte interphase (SEI) on the graphitic anode [28][29][30][31][32][33][34][35][36][37] which enables stable cycling in the low potential range as well as inertness toward aluminum to avoid anodic dissolution of the current collector on the cathode side. 38,39 In addition to performance, more general aspects like low price and environmental compatibility are important as well.…”

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confidence: 99%

Electrochemical Performance and Thermal Stability Studies of Two Lithium Sulfonyl Methide Salts in Lithium-Ion Battery Electrolytes

Murmann

Schmitz

Nowak

et al. 2015

J. Electrochem. Soc.

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Electrolyte solutions, containing the lithium sulfonyl methide salts lithium-tris(trifluoromethanesulfonyl)methide (LiTFSM) and lithium-[bis(trifluoromethylsulfonyl)-pentafluoroethylsulfonyl]methide (LiPFSM) dissolved in organic carbonate solvents, were electrochemically investigated in Li/graphite, Li/LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM) half-cells and compared to the LiPF 6 based electrolyte with regard to their ionic conductivity, electrochemical stability, thermal stability at 60 • C and the anodic dissolution behavior vs. Al. While the investigated salts show almost the same performance in Li/graphite half-cells compared to the LiPF 6 containing electrolyte, the methide salts show very promising results in Li/NCM half-cells, which depict superior capacity retention as well as higher Coulombic efficiencies compared to the LiPF 6 containing electrolyte. Taking the limited anodic stability as well as the occurring anodic dissolution into account, both salts but especially LiTFSM indicate the applicability in lithium ion battery electrolytes for cells with a cutoff potential up to 4. In the last 25 years the demand for lithium-ion batteries has grown tremendously. As a consequence, fundamental research has been carried out regarding the improvement and understanding of technological and safety related aspects. [1][2][3][4][5][6][7][8] Individual applications demand specifically tailored batteries in order to maximize the performance of the device which depicts a great challenge and opportunity for the scientific community to diversify the spectrum of compounds that can be utilized and to adapt the setup in a fast and efficient manner. 9,10 In this respect, the electrolyte, as a multifunctional battery component, can consist of a wide array of compounds such as different solvents, conductive salts and numerous additives. The combination of various electrolyte compounds opens up the possibility to tailor the electrolyte and thus, to a significant extent, the battery cell performance. 11-14The current state-of-the-art electrolyte composition is comprised of the conductive salt lithium hexafluorophosphate (LiPF 6 ) dissolved in a mixture of cyclic (e.g. ethylene carbonate and propylene carbonate [15][16][17][18][19] ) and linear carbonates (e.g. dimethyl-, diethyl-and ethyl-methyl carbonate). 11,[19][20][21][22][23][24][25] However, with increasing demands on the electrolyte regarding thermal and/or electrochemical stability, the limitations of such electrolyte mixtures are unraveled. 11,26,27 Alternative electrolyte compositions that depict certain improvements compared to the state-of-the-art electrolyte are still required to fulfil the following properties: a sufficient ionic conductivity to transport the lithium ions, the ability to form an effective solid electrolyte interphase (SEI) on the graphitic anode 28-37 which enables stable cycling in the low potential range as well as inertness toward aluminum to avoid anodic dissolution of the current collector on the cathode side. 38,39 In addition to performance, more...

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Electrochemical impedance spectroscopy study of the SEI formation on graphite and metal electrodes

Cited by 144 publications

References 13 publications

A study of 40 Ah lithium ion batteries at zero percent state of charge as a function of temperature

A study of 40 Ah lithium ion batteries at zero percent state of charge as a function of temperature

The Role of Additives in Improving Performance in High Voltage Lithium-Ion Batteries with Potentiostatic Holds

Electrochemical Performance and Thermal Stability Studies of Two Lithium Sulfonyl Methide Salts in Lithium-Ion Battery Electrolytes

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