Impedance Spectroscopy Characterization of Porous Electrodes under

Article pubs.acs.org/JPCC

Impedance Spectroscopy Characterization of Porous Electrodes under Different Electrode Thickness Using a Symmetric Cell for HighPerformance Lithium-Ion Batteries Nobuhiro Ogihara,* Yuichi Itou, Tsuyoshi Sasaki, and Yoji Takeuchi Toyota Central R&D Laboratories., Inc., Nagakute, Aichi 480-1192, Japan S Supporting Information *

ABSTRACT: To understand the relationship between the specific energy and power of lithium (Li)-ion batteries, the dependence of the internal resistance of porous electrodes with high loading weight on thickness was systematically investigated. The ionic resistance in pores (Rion) and charge-transfer resistance for Li intercalation (Rct) normalized per unit electrode geometric area were assessed using a combination of electrochemical impedance spectroscopy with symmetric cells and the transmission line model for cylindrical pores. The changes of Rion and Rct and their magnitude show opposite trends with respect to electrode thickness. For thin electrodes, Rion is lower than Rct. The specific power decreases slightly as the electrodes become thicker because the total internal resistance is predominantly affected by the charge-transfer resistance, and there is no delay of the response in the depth direction. In contrast, for thick electrodes, Rion is higher than or approximately equal to Rct, so there is a delay of the reaction in the depth direction. As a result, the power of the battery is dramatically reduced because the total internal resistance is strongly influenced by both Rion and Rct.

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actual Li-ion batteries using only Rct,app. at planar electrodes. This is because the electrodes in actual Li-ion batteries have a “porous” electrode/electrolyte interface, and electrochemical processes at the porous electrode exhibit a time distribution (Figure 1b and c). Porous electrodes mainly undergo four electrochemical processes, as shown in Figure 2a: (i) mixed conduction with both electron and ion species as electric resistance (Re), electrolyte bulk resistance (Rsol), and ionic resistance in pores (Rion); (ii) formation of an electric double layer at the electrode/electrolyte interface (Cdl); (iii) charge-transfer reaction for Li intercalation as Rct; and (iv) mass transfer to compensate for charge as diffusion. Recently, we electrochemically analyzed the actual porous electrodes of Li-ion batteries by a combination of EIS using symmetric cells (EIS-SC) and the transmission line model (TLM) theory for cylindrical pores from a macroscopic point of view to understand these electrochemical processes.27−30 Although impedance measurements using a reference electrode (three-electrode system) also have been proposed as a conventional approach, there are concerns about a mixed impedance profile including the reference electrode. In addition, it is under consideration about the optimization of position or shape of the reference electrode31−35 and the material selection for the reference electrode36,37 in terms of accuracy for porous electrode analysis. In contrast, in EIS-SC (Figure 2b), the same potential is applied

INTRODUCTION Rechargeable lithium (Li)-ion batteries are found in numerous applications and are particularly suited for large-scale use such as in automotives as well as for stationary electric power.1−4 In these applications, high-power performance is required, especially for cells with high energy density using thick electrodes, which have a high loading weight of active materials per unit electrode geometric area. The internal resistance of the electrode/electrolyte interface strongly influences power capability. Elements that influence internal resistance are the electrode and electrolyte materials and structural factors including thickness, composition, and porosity that affect tortuosity. Although the internal resistance of materials has often been reported,5−8 few studies have considered the effect of a porous electrode structure on internal resistance.9,10 For large applications, especially those using thick electrodes, the effect of the porous electrode structure on power is very large. That is, the effect of the porous electrode structure is needed to correctly interpret the electrochemical behavior. Electrochemical impedance spectroscopy (EIS) is a useful method for investigating internal resistance, such as simulation of Li-ion batteries11−13 and electric double-layer capacitors,14−20 as well as other electrochemical systems like hydrogen evolution by porous Ni electrodes.21,22 Many studies concerning internal resistance behavior of the porous electrodes have only reported the apparent charge-transfer resistance (Rct,app.) obtained by assuming a simple “planar” electrode/ electrolyte interface, which considers a parallel circuit of resistance and capacitance as a semicircle (Figure 1a).23−26 However, it is difficult to fully explain the power capability of © 2015 American Chemical Society

Received: December 17, 2014 Revised: February 7, 2015 Published: February 9, 2015 4612

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succeeded in separating the true internal resistance components of porous electrodes using this combination of methods. In this study, the dependence of the electrochemical behavior of intercalated LiNiO2-based electrodes, which are conventionally used in Li-ion batteries, on thickness was systematically investigated using EIS-SC and TLM to understand the relationship between specific energy and power in these electrodes, as shown in Figure 3. From the viewpoint of the porous electrode, changing electrode thickness corresponds to varying pore length (L) and reaction surface area (2πrL), assuming the voids of the electrodes are cylindrical pores. Rion and Rct normalized per unit electrode geometric area show different trends as electrode thickness increases. The minute details of the internal resistances and the structural factors are discussed later in the mathematical background. In other words, the relative effect of Rion and Rct on total internal resistance changes. We also examine the relationships between the individual internal resistances and power capability of actual Liion cells as pore structure parameters change.

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MATHEMATICAL BACKGROUND Impedance Theory for Cylindrical Pores According to the Transmission Line Model. For nonfaradaic (Figure 1b) and faradaic (Figure 1c) processes at porous electrodes, the overall impedance is expressed as eqs 1 and 2, respectively.41,42,47

Figure 1. Schematic representations of electrode structures and their equivalent circuit models.

Znonfaradaic =

R ion, L jωCdl, A·2πr

coth

R ion, L·jωCdl, A·2πr L (1)

Zfaradaic = R ion, L·R ct, A (1 + jωR ct, A·Cdl, A)·2πr

coth

R ion, L·(1 + jωR ct, A·Cdl, A)·2πr R ct, A

L

(2)

The limiting values of the real (Z′ω) as ω → 0 in nonfaradaic, and faradaic processes are shown by eqs 3 and 4, respectively. R ion 3

(3)

R ion + R ct 3

(4)

Z′nonfaradaic, ω→ 0 = Z′faradaic, ω→ 0 =

where Rion is the mobility of Li ions inside the porous electrodes. From these mathematical equations, Rion can be expressed as shown in eqs 5 and 6.

Figure 2. (a) Schematic illustration of respective internal resistances at porous electrodes during lithium intercalation and (b) representative schematic cell configurations for AC impedance measurement at an asymmetric full-type cell using positive and negative electrodes, asymmetric so-called single electrode-type cell using positive (or negative) and lithium metal electrodes, and symmetric-type cell using two identical electrodes.

R ion = R ion, L × R ion, L =

ρ πr 2

L n

(5) (6)

where Rion,L is ionic resistance per unit pore length. In addition, Rct is expressed as eq 7.

to two electrodes before measurement, and then both are used as electrodes in the symmetric cell. This technique can focus on the impedance of a single electrode without affecting the other electrodes, unlike in EIS using Li metal as the counter or reference electrodes. A similar concept of the impedance analysis using symmetric cells was subsequently reported by other groups.38−40 TLM has been used to describe porous electrodes as cylindrical pores for both nonfaradaic (Figure 1b) 14−19 and faradaic processes (Figure 1c).41−47 We

R ct =

R ct, A 2πrL

(7)

where Rct,A is the charge-transfer resistance per unit electroactive surface area. Using this combination approach, we have succeeded in separating the individual electrochemical parameters and corresponding kinetic interpretation from temperature dependence. 4613

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and polyvinylidene fluoride (PVDF) as a binder (91:5:4 weight ratio, respectively) in N-methyl-2-pyrrolidone (NMP) on aluminum foil. LiNi0.15Co0.15Al0.05Mg0.05O2 active material was prepared by a coprecipitation method. Graphite-based negative electrodes were prepared using the same procedure as for the positive electrodes. A mixture of graphite and PVDF (90:10 weight ratio, respectively) was coated on copper foil. Both electrodes were dried at 120 °C under vacuum for at least 10 h before constructing the electrochemical cell. Positive and negative electrodes with several loading weights were prepared to keep the same porosity and capacity ratios between positive and negative electrodes. The electrolyte used in this study was 1.0 M LiPF6 dissolved in a solution of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) (30:40:30 volume ratio, respectively). A microporous polypropylene film was used as a separator. Electrochemical Measurements. All electrochemical measurements were performed using cylindrical-type cells or laminate-type pouch cells assembled in an argon-filled glovebox. For charge−discharge measurements to determine power and energy densities, the cylindrical-type cells were cycled between 4.1 and 3.0 V at least once at a low current density of 0.05 mA cm−2 to determine energy densities and then cycled at various current densities between 0.05 and 5 mA cm−2 to confirm power densities. Specific energy and power were normalized from the values for the thinnest electrode. The I−V resistance of the cylindrical-type cells was calculated from each of the charge−discharge voltage difference and current density and normalized per unit electrode geometric area. For EIS-SC measurements of nonfaradaic processes to determine Rion, identical electrodes were assembled with the separator filled with electrolyte. Prior to EIS-SC measurements of faradaic processes to determine Rct, cells with positive and negative electrodes were prepared with the separator, cycled between 3.0 and 4.1 V at least once at a current density of 0.05 mA cm−2 and maintained at 3.685 V for an additional 2 h to set the state of charge (SOC) at 50%. The symmetric cells were then prepared with electrodes taken from this cell. AC impedance measurements (Solatron 1260/1286, England) of cylindrical and symmetric cells were performed at open-circuit potential. The frequency was varied from 100 kHz to 100 mHz with a perturbation amplitude of 10 mV (peak to peak). Measurements were performed between −10 and 60 °C. The fitting of the experimental impedance using symmetric cell data was carried out with Zview software (Scribner Associates, Inc., USA).48 The equivalent circuit for fitting of impedance spectra at the SOC of 0% and 50% used the generalized finite length Warburg element open-circuit terminus (Wo) and short-circuit terminus (Ws) for descriptive purposes, respectively.17,49 Rion and Rct were calculated by using eqs 3 and 4 from the resistance values obtained by fitting. All of the internal resistances obtained by fitting were normalized per unit electrode geometric area.

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RESULTS AND DISCUSSION Dependence of the Battery Performance on Electrode Thickness. Figure 4a shows the relationship between specific power and energy of cylindrical full-type cells consisting of LiNiO2-based (positive) and graphite carbon (negative) electrodes for various electrode thicknesses ranging from ca. 20 to 75 μm of positive electrodes. With increasing electrode thickness, the specific energy increases, while the specific power reduces. The increase of specific energy with electrode

Figure 3. Cross-sectional SEM images of the LiNiO2-based positive electrodes at respective electrode thickness.

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EXPERIMENTAL SECTION Materials. Intercalated LiNiO2-based positive electrodes were prepared by coating a dispersion of LiNi0.15Co0.15Al0.05Mg0.05O2, carbon black as conducting agent, 4614

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Figure 4. (a) Relation between power and energy densities for cylindrical Li-ion cells with different electrode thickness. The numbers are positive electrode thickness. (b) Dependence of the I−V resistance (circles) and the corresponding inverse of the I−V resistance (squares) of the same cell on electrode thickness. (c) Dependence of Nyquist plots for cylindrical Li-ion cells at 0 °C on electrode thickness. (d) Dependence of chargetransfer resistance of positive electrode (circles) and the corresponding inverse of charge-transfer resistance (squares) on electrode thickness obtained by fitting.

Figure 5. Dependence of Nyquist plots for symmetric cells using two identical positive electrodes at 0 °C on electrode thickness for electrodes prepared at SOC of (a) 0% and (b) 50%. Dependence of each internal resistance at 0 °C on electrode thickness: (c) ionic resistance in pores (Rion) and (d) charge-transfer resistance of lithium intercalation reaction (Rct) obtained by fitting with TLM (circles) and the corresponding inverse of Rct (squares). Open marks in (c) and (d) are only a result of the impedance analysis using symmetric cells.

thickness means that the proportion of active materials in the total volume including the current collector for both electrodes increases. In contrast, the power decay with increasing

electrode thickness occurred differently in two thickness regions, i.e., a slight decline in the thin-electrode region (region I) and a large decline in the thick-electrode region (region II). 4615

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Scheme 1. Schematic Illustration of the Effects of Pore Length and Reaction Surface Area for Each Internal Resistance

Rion and Rct, respectively. Figure 5a and b shows the dependence of Nyquist plots for the intercalated LiNiO2based electrodes on electrode thickness using a symmetric cell at SOC 0% and 50%, respectively. In terms of impedance behavior, the results obtained in this study were consistent with those reported previously for all electrode thicknesses.27 The Nyquist plots for SOC 0% (Figure 5a) are straight lines with a slope of 45° to the real axis in the high-frequency region (101− 102 Hz), with vertical lines in the low-frequency region (10−1− 101 Hz) indicative of the typical electrical blocking behavior of porous electrodes without a charge-transfer reaction. This blocking behavior was observed for all electrode thicknesses and temperature conditions (see Figure S1 of the Supporting Information). The length of the straight line with a slope of 45° in the high-frequency region, which reflects Rion, increases with electrode thickness. Conversely, the Nyquist plots for SOC 50% (Figure 5b) show similar profiles of the slope of 45° as seen for SOC 0% in the high-frequency region (see Figure S2 of the Supporting Information) and appeared as a semicircle at low frequencies (10−1−101 Hz). The size of the semicircle in the low-frequency region, which reflects Rct, decreases with increasing electrode thickness. As shown in Figure S2 of the Supporting Information, the behavior at high frequency is consistent with ionic resistance in pores. The matching behavior for SOC 0% and 50% at high frequency means that the ionic conduction in the porous electrodes occurs independently of the charge-transfer reaction, which is a kind of faradaic reaction. As shown in eqs 5 and 7 and Figure S3 of the Supporting Information, the quantitative values of Rion and Rct can be easily understood from the experimental Nyquist plots. Figure 5c and d show the dependence of Rion and Rct, respectively, on electrode thickness obtained by fitting (see Figure S3 and Tables S1 and S2 of the Supporting Information). Rion increases linearly with electrode thickness, while Rct is in inverse proportion to the electrode thickness. We take into account the effect of pore structure parameters of the porous electrodes on their respective internal resistance per unit electrode geometric area. As shown in Scheme 1, from eq 5, the linearity between Rion and electrode thickness suggests that Rion affects pore length (L). Conversely, eq 7 shows that Rct is in inverse proportion to electrode thickness, suggesting that Rct affects the electroactive surface area (2πrL). Overall, Rion and Rct obtained from EIS-SC show opposite trends with respect to electrode thickness. Rion is lower than Rct in region I but higher in region II. Relationship between the Battery Performance and the Internal Resistance Component. The contribution of internal resistance components to the total internal resistance is next considered from the experimental results obtained so far. Figure 6 shows the dependence of the internal resistance on electrode thickness obtained from EIS-SC. The inverse of Rct is proportional to electrode thickness. With reference to eq 4, the inverse of the total internal resistance plus one-third of Rion,

This means that different factors in terms of internal resistance can affect the power decay. As shown in Figure 4b, the I−V resistance of the same cylindrical full-type cell decreased dramatically in region I and slightly in region II with increasing electrode thickness. An inverse plot of the I−V resistance also shows a nonlinear profile as a function of electrode thickness. To confirm that the rate capability and I−V resistance described above arise from the internal resistance, AC impedance measurements of the same cylindrical full-type cells were conducted. Figure 4c shows the Nyquist plots of the full-type cells with different electrode thickness with a state of charge (SOC) of 50%. Two overlapping semicircles were observed at high- (101−103 Hz) and low-frequency regions (100−101 Hz) for all electrode thicknesses. The two overlapping semicircles decreased in size with increasing electrode thickness. Additionally, a straight line with a slope of 45° appeared at very low frequency (10−1−100 Hz), corresponding to typical semi-infinite diffusion for long-range ionic diffusion in the bulk of active-electrode materials. For quantitative analysis of the Nyquist plots, an equivalent circuit considering a simple planar electrode, which is two parallel circuits in series (inset in Figure 4c), was used for fitting. In this model, Rsol is the electrolyte bulk resistance; Cdl,app.1 and Rct,app.1 represent apparent double-layer capacitance and charge-transfer resistance corresponding to the negative electrode, respectively; and Cdl,app.2, Rct,app.2, and Ws are apparent double-layer capacitance and charge-transfer resistance corresponding to the positive electrode and Warburg impedance, respectively.50,51 Figure 4d shows the dependence of the charge-transfer resistance for the positive electrode, Rct,app.2, on thickness obtained by fitting of the Nyquist plots using the equivalent circuit described above. Rct,app.2 decreased dramatically in region I and slightly in region II with increasing electrode thickness, which indicates the same tendency as the I−V resistance obtained by the charge− discharge test in Figure 4b. An inverse plot of Rct,app.2 shows a linear profile in region I and nonlinear profile in region II. The increasing electrode thickness provides an increasing reaction surface area. Considering that the change in Rct,app.2 is assumed to be only charge-transfer resistance, according to eq 7, the inverse of Rct,app.2 increases linearly with electrode thickness. However, our experimental results are different from this expectation; the profile of Rct,app.2 in region II cannot be explained by eq 7. As implied by the power decay shown in Figure 4a, these results indicate that another resistance component that is different from the charge-transfer resistance may contribute to the total internal resistance, especially in region II. Dependence of the Individual Internal Resistances on Electrode Thickness. EIS using full-type cells cannot analyze the internal resistance of porous electrodes in detail because of the overlapping profiles of Nyquist plots for the positive and negative electrodes.52,53 To examine the internal resistance of the porous electrodes in greater detail, EIS-SC for the positive electrodes was conducted at SOC of 0% and 50% to determine 4616

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both Rion and Rct may contribute to it, the power decay dramatically decreases compared with the case for Rct alone like region I. Rct is determined by the electrode and electrolyte materials. Although Rion is determined by the bulk electrolyte conductivity and porous electrode structure, for thick electrodes, the major factor affecting power performance is structure. Importantly, this means that experimental power capabilities (or C-rate capabilities) measured for very thin films (such as lower than 1 mg cm−2 of active material loading per unit electrode geometric area) make only small contributions to actual cell performance.

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CONCLUSIONS In conclusion, involvement of the internal resistance of the charge-transfer reaction Rct and ionic conduction at the porous electrode/electrolyte interface Rion was confirmed to depend on electrode thickness by considering the EIS-SC measurements and TLM theory for cylindrical pores. The individual internal resistance components of Rion and Rct show opposite trends with respect to electrode thickness because Rion affects pore length, whereas Rct inversely affects electroactive surface area. With respect to the effect of the porous-electrode structure on the power capability of actual full-type cells, we experimentally confirmed that marked power decay occurred when Rion affected Li-ion conduction in the electrolyte-filled pores rather than Rct. This work developed an analysis system that can examine the relationship between basic electrochemistry and actual battery performance. In batteries with high energy density at high-loading active materials and thick electrodes, the ionic-conduction pathway in the porous electrodes strongly affects power capability.

Figure 6. Dependence of the inverse of internal resistance components 1/Rct (squares) and 1/(Rion/3 + Rct) (circles) on electrode thickness. Inset: relationship of Rion and Rct with electrode thickness determined from the results in Figure 5. Open marks are only a result of the impedance analysis using symmetric cells.

Rion/3 + Rct, shows nonlinear behavior. The inset of Figure 6 reveals that in region II where Rion is greater than or approximately equal to Rct the dissociation of the two curves is marked. The nonlinear behavior of the total resistance determined from EIS-SC shown in Figure 6 is in agreement with the I−V resistance in Figure 4b and Rct,app. of the observed cylindrical full-type cells in Figure 4d. This means the total resistance obtained from EIS-SC reflects the behavior of the cylindrical cell well. This deviation of the total internal resistance from Rct implies that Rct,app. of the full-type cells would include both Rct and Rion. Rct,app. is influenced by Rion. Consequently, the total internal resistance of the porous electrodes is greatly affected by the porous structure, especially for thick electrodes at high loading weight of active materials. When discussing the true Rct at the electrode/electrolyte interface in porous electrodes, if Rion is changed considerably by factors such as electrode thickness or resistivity of bulk electrolyte, Rct considering the effect of ionic resistance in pores should be determined instead of Rct,app. obtained from the full-type cells. From this viewpoint, the method proposed in this study is suitable for examining the true porous electrode/ electrolyte interface. It should be noted that the activation energy obtained for Rion and Rct is constant regardless of electrode thickness (Figure S4 of the Supporting Information). This means that physical properties are unchanged as the electrode thickness varies. This relationship between the specific power and internal resistance of the cylindrical full-type cells can be described theoretically using the TLM. The relationship between Rct and Rion can be considered a parallel circuit in the TLM from the point of view shown in Figure 1c. In this case, the higher resistance, either Rct or Rion, dominates the rate-determining process. The inset of Figure 6 shows that when Rion is lower than Rct at a thin electrode (region I) the rate-determining process is Rct. Thus, there is essentially no delay in the response of the reaction in the depth direction. As a consequence, the reduction of power is minimal because only Rct has an effect. In contrast, when Rion is higher than or approximately equal to Rion at a thick electrode (region II), the rate-determining process is the conduction of Li ions in the porous electrodes. Therefore, the reaction in the depth direction is delayed. That is, because

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ASSOCIATED CONTENT

S Supporting Information *

Complementary figures pertaining to EIS measurements, representative fitting results, and activation energies. This material is available free of charge via the Internet at http:// pubs.acs.org.

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS

The authors thank the members of the Battery Fundamental Research Laboratory of Toyota Central R&D Laboratories., Inc., for helpful comments and technical support.

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LIST OF SYMBOLS L unit pore length, cm r pore radius, cm ρ electrolyte resistance, Ωcm S electrode surface area, cm2 n number of pores per unit electrode surface area Cdl,A electric double-layer capacitance per unit electroactive surface area, F cm2 Cdl total electric double-layer capacitance (Cdl = Cdl,A 2πrL), F 4617

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(22) Hitz, C.; Lasia, A. Experimental Study and Modeling of Impedance of the Her on Porous Ni Electrodes. J. Electroanal. Chem. 2001, 500, 213−222. (23) Recham, N.; Chotard, J. N.; Dupont, L.; Delacourt, C.; Walker, W.; Armand, M.; Tarascon, J. M. A 3.6 V Lithium-Based Fluorosulphate Insertion Positive Electrode for Lithium-Ion Batteries. Nat. Mater. 2010, 9, 68−74. (24) Okumura, T.; Fukutsuka, T.; Matsumoto, K.; Orikasa, Y.; Arai, H.; Ogumi, Z.; Uchimoto, Y. Lithium-Ion Transfer Reaction at the Interface between Partially Fluorinated Insertion Electrodes and Electrolyte Solutions. J. Phys. Chem. C 2011, 115, 12990−12994. (25) Nayak, P. K.; Grinblat, J.; Levi, M.; Markovsky, B.; Aurbach, D. Structural and Electrochemical Evidence of Layered to Spinel Phase Transformation of Li and Mn Rich Layered Cathode Materials of the Formulae Xli[Li1/3Mn2/3]O2.(1-X)LiMn1/3Ni1/3Co1/3O2 (X = 0.2, 0.4, 0.6) Upon Cycling. J. Electrochem. Soc. 2014, 161, A1534−A1547. (26) Zhou, J.; Li, R.; Fan, X.; Chen, Y.; Han, R.; Li, W.; Zheng, J.; Wang, B.; Li, X. Rational Design of a Metal−Organic Framework Host for Sulfur Storage in Fast, Long-Cycle Li−S Batteries. Energy Environ. Sci. 2014, 7, 2715−2724. (27) Ogihara, N.; Kawauchi, S.; Okuda, C.; Itou, Y.; Takeuchi, Y.; Ukyo, Y. Theoretical and Experimental Analysis of Porous Electrodes for Lithium-Ion Batteries by Electrochemical Impedance Spectroscopy Using a Symmetric Cell. J. Electrochem. Soc. 2012, 159, A1034−A1039. (28) Ogihara, N.; Itou, Y.; Kawauchi, S.; Okuda, C.; Takeuchi, Y.; Ukyo, Y. Electrochemical Impedance Analysis and Applications of Porous Electrodes for Lithium-Ion Batteries. Meet. Abstr. 2012, MA2012−02, 723. (29) Ogiahra, N.; Itou, Y.; Kawauchi, S.; Kobayashi, T.; Takeuchi, Y. Potential Dependence of Electrochemical Behavior of Porous Electrodes for Li-Ion Batteries. Meet. Abstr. 2013, MA2013−02, 947. (30) Itou, Y.; Ogihara, N.; Okuda, C.; Sasaki, T.; Nakano, H.; Kobayashi, T.; Takeuchi, Y. Electrochemical Analysis and Novel Characterization of Porous Electrodes by Using Transmission Line Model for Lithium-Ion Batteries. Meet. Abstr. 2014, MA2014−04, 611. (31) Zhou, J.; Notten, P. H. L. Development of Reliable Lithium Microreference Electrodes for Long-Term in Situ Studies of LithiumBased Battery Systems. J. Electrochem. Soc. 2004, 151, A2173−A2179. (32) Dees, D. W.; Jansen, A. N.; Abraham, D. P. Theoretical Examination of Reference Electrodes for Lithium-Ion Cells. J. Power Sources 2007, 174, 1001−1006. (33) Ender, M.; Weber, A.; Ivers-Tiffee, E. Analysis of ThreeElectrode Setups for AC-Impedance Measurements on Lithium-Ion Cells by Fem Simulations. J. Electrochem. Soc. 2012, 159, A128−A136. (34) Huang, C.; Zhuang, S.; Tu, F. Electrode/Electrolyte Interfacial Behaviors of LiCoO2/Mixed Graphite Li-Ion Cells During Operation and Storage. J. Electrochem. Soc. 2012, 160, A376−A382. (35) Mendoza-Hernandez, O. S.; Ishikawa, H.; Nishikawa, Y.; Maruyama, Y.; Sone, Y.; Umeda, M. State of Charge Dependency of Graphitized-Carbon-Based Reactions in a Lithium-Ion Secondary Cell Studied by Electrochemical Impedance Spectroscopy. Electrochim. Acta 2014, 131, 168−173. (36) Dollé, M. l.; Orsini, F. o.; Gozdz, A. S.; Tarascon, J.-M. Development of Reliable Three-Electrode Impedance Measurements in Plastic Li-Ion Batteries. J. Electrochem. Soc. 2001, 148, A851−A857. (37) Abraham, D. P.; Poppen, S. D.; Jansen, A. N.; Liu, J.; Dees, D. W. Application of a Lithium−Tin Reference Electrode to Determine Electrode Contributions to Impedance Rise in High-Power LithiumIon Cells. Electrochim. Acta 2004, 49, 4763−4775. (38) Kim, G. Y.; Petibon, R.; Dahn, J. R. Effects of Succinonitrile (Sn) as an Electrolyte Additive on the Impedance of Licoo2/Graphite Pouch Cells During Cycling. J. Electrochem. Soc. 2014, 161, A506− A512. (39) Nakura, K.; Ariyoshi, K.; Ogaki, F.; Takaoka, K.; Ohzuku, T. Characterization of Lithium Insertion Electrodes: A Method to Measure Area-Specific Impedance of Single Electrode. J. Electrochem. Soc. 2014, 161, A841−A846. (40) Momma, T.; Yokoshima, T.; Nara, H.; Gima, Y.; Osaka, T. Distinction of Impedance Responses of Li-Ion Batteries for Individual

REFERENCES

(1) Chu, S.; Majumdar, A. Opportunities and Challenges for a Sustainable Energy Future. Nature 2012, 488, 294−303. (2) Bruce, P. G.; Freunberger, S. A.; Hardwick, L. J.; Tarascon, J. M. Li-O2 and Li-S Batteries with High Energy Storage. Nat. Mater. 2012, 11, 19−29. (3) Dunn, B.; Kamath, H.; Tarascon, J. M. Electrical Energy Storage for the Grid: A Battery of Choices. Science 2011, 334, 928−935. (4) Thackeray, M. M.; Wolverton, C.; Isaacs, E. D. Electrical Energy Storage for TransportationApproaching the Limits of, and Going Beyond, Lithium-Ion Batteries. Energy Environ. Sci. 2012, 5, 7854− 7863. (5) Yamada, I.; Abe, T.; Iriyama, Y.; Ogumi, Z. Lithium-Ion Transfer at LiMn2O4 Thin Film Electrode Prepared by Pulsed Laser Deposition. Electrochem. Commun. 2003, 5, 502−505. (6) Abe, T.; Fukuda, H.; Iriyama, Y.; Ogumi, Z. Solvated Li-Ion Transfer at Interface between Graphite and Electrolyte. J. Electrochem. Soc. 2004, 151, A1120−A1123. (7) Yamada, Y.; Iriyama, Y.; Abe, T.; Ogumi, Z. Kinetics of Lithium Ion Transfer at the Interface between Graphite and Liquid Electrolytes: Effects of Solvent and Surface Film. Langmuir 2009, 25, 12766−12770. (8) Sagane, F.; Abe, T.; Ogumi, Z. Li+-Ion Transfer through the Interface between Li+-Ion Conductive Ceramic Electrolyte and Li+Ion-Concentrated Propylene Carbonate Solution. J. Phys. Chem. C 2009, 113, 20135−20138. (9) Levi, M. D.; Aurbach, D. Impedance of a Single Intercalation Particle and of Non-Homogeneous, Multilayered Porous Composite Electrodes for Li-Ion Batteries. J. Phys. Chem. B 2004, 108, 11693− 11703. (10) Levi, M. D.; Aurbach, D. Distinction between Energetic Inhomogeneity and Geometric Non-Uniformity of Ion Insertion Electrodes Based on Complex Impedance and Complex Capacitance Analysis. J. Phys. Chem. B 2005, 109, 2763−73. (11) Doyle, M.; Meyers, J. P.; Newman, J. Computer Simulations of the Impedance Response of Lithium Rechargeable Batteries. J. Electrochem. Soc. 2000, 147, 99−110. (12) Meyers, J. P.; Doyle, M.; Darling, R. M.; Newman, J. The Impedance Response of a Porous Electrode Composed of Intercalation Particles. J. Electrochem. Soc. 2000, 147, 2930−2940. (13) Devan, S.; Subramanian, V. R.; White, R. E. Analytical Solution for the Impedance of a Porous Electrode. J. Electrochem. Soc. 2004, 151, A905−A913. (14) Qu, D. Y.; Shi, H. Studies of Activated Carbons Used in DoubleLayer Capacitors. J. Power Sources 1998, 74, 99−107. (15) Song, H. K.; Jung, Y. H.; Lee, K. H.; Dao, L. H. Electrochemical Impedance Spectroscopy of Porous Electrodes: The Effect of Pore Size Distribution. Electrochim. Acta 1999, 44, 3513−3519. (16) Jang, J. H.; Oh, S. M. Complex Capacitance Analysis of Porous Carbon Electrodes for Electric Double-Layer Capacitors. J. Electrochem. Soc. 2004, 151, A571−A577. (17) Jang, J. H.; Yoon, S.; Ka, B. H.; Jung, Y. H.; Oh, S. M. Complex Capacitance Analysis on Leakage Current Appearing in Electric Double-Layer Capacitor Carbon Electrode. J. Electrochem. Soc. 2005, 152, A1418−A1422. (18) Itagaki, M.; Suzuki, S.; Shitanda, I.; Watanabe, K.; Nakazawa, H. Impedance Analysis on Electric Double Layer Capacitor with Transmission Line Model. J. Power Sources 2007, 164, 415−424. (19) Itagaki, M.; Hatada, Y.; Shitanda, I.; Watanabe, K. Complex Impedance Spectra of Porous Electrode with Fractal Structure. Electrochim. Acta 2010, 55, 6255−6262. (20) Taberna, P. L.; Simon, P.; Fauvarque, J. F. Electrochemical Characteristics and Impedance Spectroscopy Studies of CarbonCarbon Supercapacitors. J. Electrochem. Soc. 2003, 150, A292−A300. (21) Los, P.; Lasia, A.; Menard, H.; Brossard, L. Impedance Studies of Porous Lanthanum-Phosphate-Bonded Nickel Electrodes in Concentrated Sodium-Hydroxide Solution. J. Electroanal. Chem. 1993, 360, 101−118. 4618

DOI: 10.1021/jp512564f J. Phys. Chem. C 2015, 119, 4612−4619

Article

The Journal of Physical Chemistry C Electrodes Using Symmetric Cells. Electrochim. Acta 2014, 131, 195− 201. (41) de Levie, R. On Porous Electrodes in Electrolyte Solutions. Electrochim. Acta 1963, 8, 751−780. (42) de Levie, R. On Porous Electrodes in Electrolyte SolutionsIv. Electrochim. Acta 1964, 9, 1231−1245. (43) Bisquert, J. Influence of the Boundaries in the Impedance of Porous Film Electrodes. Phys. Chem. Chem. Phys. 2000, 2, 4185−4192. (44) Hansen, C. P.; Bertelsen, S. Boerhaave’s Syndrome: Spontaneous Rupture of the Oesophagus. Ann. Chir. Gynaecol. 1988, 77, 138−41. (45) Barcia, O. E.; D’Elia, E.; Frateur, I.; Mattos, O. R.; Pébère, N.; Tribollet, B. Application of the Impedance Model of De Levie for the Characterization of Porous Electrodes. Electrochim. Acta 2002, 47, 2109−2116. (46) Bisquert, J.; Gratzel, M.; Wang, Q.; Fabregat-Santiago, F. ThreeChannel Transmission Line Impedance Model for Mesoscopic Oxide Electrodes Functionalized with a Conductive Coating. J. Phys. Chem. B 2006, 110, 11284−90. (47) Itagaki, M.; Suzuki, S.; Shitanda, I.; Watanabe, K. Electrochemical Impedance and Complex Capacitance to Interpret Electrochemical Capacitor. Electrochemistry 2007, 75, 649−655. (48) Johson, D. Zview: Version 3.2; Scribner Associates, Inc.: Southern Pines, 2009. (49) Sugimoto, W.; Iwata, H.; Yokoshima, K.; Murakami, Y.; Takasu, Y. Proton and Electron Conductivity in Hydrous Ruthenium Oxides Evaluated by Electrochemical Impedance Spectroscopy: The Origin of Large Capacitance. J. Phys. Chem. B 2005, 109, 7330−7338. (50) Kondo, H.; Takeuchi, Y.; Sasaki, T.; Kawauchi, S.; Itou, Y.; Hiruta, O.; Okuda, C.; Yonemura, M.; Kamiyama, T.; Ukyo, Y. Effects of Mg-Substitution in Li(Ni,Co,Al)O2 Positive Electrode Materials on the Crystal Structure and Battery Performance. J. Power Sources 2007, 174, 1131−1136. (51) Aurbach, D. Review of Selected Electrode−Solution Interactions Which Determine the Performance of Li and Li Ion Batteries. J. Power Sources 2000, 89, 206−218. (52) Chen, C. H.; Liu, J.; Amine, K. Symmetric Cell Approach Towards Simplified Study of Cathode and Anode Behavior in Lithium Ion Batteries. Electrochem. Commun. 2001, 3, 44−47. (53) Chen, C. H.; Liu, J.; Amine, K. Symmetric Cell Approach and Impedance Spectroscopy of High Power Lithium-Ion Batteries. J. Power Sources 2001, 96, 321−328.

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DOI: 10.1021/jp512564f J. Phys. Chem. C 2015, 119, 4612−4619