Impedance Evolution Characteristics in Lithium-Ion Batteries

Abstract

A three-electrode cell can be a useful tool for measuring electrode-level and cell-level electrochemical characteristics, such as the impedance response and potential variations in lithium-ion cells. In this paper, a reliable three-electrode coin cell setup is introduced, which improves the stability and accuracy of electrochemical measurements by modifying the electrode alignment and employing Li 4 Ti 5 O 12 as a reference electrode. An important highlight is the ability to obtain impedance evolution characteristics at different depth of discharge (DOD) for an individual electrode and the full cell based on both the frequency response analysis and the carrier function Laplace transform characteristics. The reliability of the proposed modified three-electrode coin cell setup has been validated by analyzing the impedance response of symmetric and full cells, and the voltage profiles of the full cell along with the positive/negative electrode contributions. The importance of the resistance contributions from the negative and positive electrodes to the full cell impedance evolution at different DOD is highlighted. Lithium-ion batteries (LIBs) are popular candidates for use in electric vehicles and in the application of portable electronic devices due to their favorable energy density and power capability.1-4 The wide usage of LIBs, in recent years, has raised interest in the observation of their performance and degradation phenomena. The typical configuration of battery cells, which only have anode and cathode, is suitable when the whole cell is the objective of the analysis. However, the typical cell configuration is limited when the interest is in separately studying the electrochemical characteristic of each electrode. To study the electrochemical characteristics of anode and cathode separately during the charging and discharging processes, a three-electrode cell, which includes a reference electrode (RE), working electrode (WE), and counter electrode (CE), has been introduced. By investigating the electrochemical impedance spectroscopy (EIS) and potential from three-electrode cell, the influence of the cathode and anode on the cell performance and degradation phenomena can be separately analyzed and characterized. 5-9The three-electrode cell can be setup with the configuration of plastic pouch cell, 10-12 steel cell housing, 13 or Swagelok cell. 14,15 These previous setups have the disadvantage of having a large size and high cost. To overcome these disadvantages, the three-electrode coin cell setup was selected due to its advantage of being well-sealed, portable, and low cost. To the best of the authors' knowledge, few of these three-electrode coin cell setups have been implemented to study the EIS and full cell performance (electrode potential). Delacourt et al. 16 developed a T-cell-like three-electrode coin cell setup. In this T-celllike setup, the distortion in the EIS measurement, especially in the low frequency region, can be attributed primarily to the alignment and uneven separation of the RE, CE, and ...

Breathing and oscillating growth of solid-electrolyte-interphase upon electrochemical cycling

“…10 In particular, studies of the live-formation and evolution of SEI upon electrochemical cycling has been limited to mostly macroscopic and phenomenological tools like impedance. 8,15 Whether a formed SEI is truly stable, as expected in conventional wisdom, or changes upon electrochemical cycling remains to be explored with the help of elemental and chemically sensitive probes.…”

Critical Review of the Use of Reference Electrodes in Li-Ion Batteries: A Diagnostic Perspective

“…A widely used controlled-current technique in the LIB field is galvanostatic cycling with potential limits. With this technique, the use of an RE enables the simultaneous acquisition of potential profiles of both positive and negative electrodes, in addition to that of the full cell, which is not possible in a two-electrode cell configuration (Figure 4) [24,[31][32][33][34][35][36][37][38][39][40][41][42]. Controlled-potential experiments can be an extremely useful and versatile tool for fundamental electrochemical studies, e.g., reaction kinetics at single electrodes or electrolyte electrochemical stability.…”

“…As mentioned above, EIS is the method of choice to study the electrochemical properties of various battery electrodes as a function of cycling or state of charge [54]. Positive electrode active materials including V6O13 [14,55], LiMn2O4 [56,57] [72,73], LiNi0.5Mn1.5O4 [74], LiNi0.5Mn0.3Co0.2O2 [36,75], and LiNi0.6Mn0.6Co0.2O2 [76], as well as negative electrode active materials, such as carbons [35,60,68,[77][78][79][80], graphite [16,31,[36][37][38]57,[62][63][64][65][66][67][68][69][70][71][72][73][74][75]81,82], Sn-containing composites [82,83], LiTi2(PO4)3 [15], Li4Ti5O12 [61], and Si-containing composites [34,84,85] have...…”

“…It has also been reported that overcharge conditions produce a high impedance at the positive electrode, while over discharge of the battery results in a higher impedance at the negative electrode [72]. Interestingly, when metallic Li is used as the negative electrode instead of a In general, three-electrode measurements have shown that the main contribution to the impedance of a LIB cell originates from the positive electrode [37,63,71,73,81]. The negative electrode, which generally comprises a graphitic active material, commonly exhibits a stable impedance contribution independent of the state of charge of the battery [63,71,73].…”

Analysis of electrochemical impedance spectroscopy response for commercial lithium-ion batteries: modeling of equivalent circuit elements

“…Rechargeable lithium-ion (Li-ion) batteries (LIBs) are currently admitted as the preferred technology for electrical energy storage and power delivery solutions [2]. LIBs are also a substantial technology for electric vehicles [3] and choices of this technology extend beyond portable electronics [4] to electric vehicles [5] and grid energy storage systems [6].…”