Electrochemical Impedance Spectroscopy of PEO-LATP Model Multilayers: Ionic Charge Transport and Transfer

Abstract

Solid-state batteries are seen as a possible revolutionary technology, with increased safety and energy density compared to their liquid-electrolyte-based counterparts. Composite polymer/ceramic electrolytes are candidates of interest to develop a reliable solid-state battery due to the potential synergy between the organic (softness ensuring good interfaces) and inorganic (high ionic transport) material properties. Multilayers made of a polymer/ceramic/polymer assembly are model composite electrolytes to investigate ionic charge transport and transfer. Here, multilayer systems are thoroughly studied by electrochemical impedance spectroscopy (EIS) using poly(ethylene oxide) (PEO)-based polymer electrolytes and a NaSICON-based ceramic electrolyte. The EIS methodology allows the decomposition of the total polarization resistance ( R p ) of the multilayer cell as being the sum of bulk electrolyte (migration, R el ), interfacial charge transfer ( R ct ), and diffusion resistance ( R dif ), i.e., R p = R el + R ct + R dif . The phenomena associated with R el , R ct , and R dif are well decoupled in frequencies, and none of the contributions is blocking for ionic transport. In addition, straightforward models to deduce R el , R dif , and t + (cationic transference number) of the multilayer based on the transport properties of the polymer and ceramic electrolytes are proposed. A kinetic model based on the Butler–Volmer framework is also presented to model R ct and its dependency with the polymer electrolyte salt concentration ( C Li + ). Interestingly, the polymer/ceramic interfacial capacitance is found to be independent of C Li + .

Characterization of Li+ Transport through the Organic-Inorganic Interface by using Electrochemical Impedance Spectroscopy

“…According to Isaac et al, a resistance in parallel with a constant phase element models this latter contribution. 9 Using the equivalent circuit reported in Fig. 4b, the fit with the experimental data demonstrates good agreement in the zones a and b (sum of square = 40).…”

“…11,12 Under these conditions, a R interface of 9 kΩ.cm 2 was estimated at 70 °C. Notably unlike the previous studies, 8,9 this model describes the heterogeneities present at the interface via a de Levie element.…”

“…These findings align with similar observations made in multilayer systems involving Li 1+x+y Al x Ti 2−x Si y P 3−y O 12 . 9 Using a methodology comparable to Gupta et al, 8 they demonstrated that the interfacial resistance, R interface , is inversely proportional to the concentration of Li + in the polymer, within the range of concentration of 0.01-2.5 M (R interface ∼ 2.10 3 Ω.cm 2 and 20 Ω.cm 2 , respectively at 30 °C and 70 °C). Interestingly, Langer et al 10 observed an additional ion transfer process attributed to interface processes on PEO-LiClO 4 ||LLZO||PEO-LiClO 4 multilayers.…”

Electrochemical Methods of Transference Number Determination for Polymer Electrolyte Systems: A Comparative Study

“…Nonetheless, this method was used early on, for example by Peled, 7 Kumar 8 and Wohde, 9 and very recently by Isaac and coworkers. 10 To this reservation should be added the practical limitation of high temperatures. Due to the high Warburg resistance, Z d (0) cannot be extracted at low temperatures within a reasonable frequency window.…”

Improved Tool for Predicting Skin Irritation on Reconstructed Human Epidermis Models Based on Electrochemical Impedance Spectroscopy

“…In the last few years, EIS has established itself as one of the most popular analytical techniques in material research and is used in a variety of areas and analyses such as corrosion studies [6]; monitoring the ionic properties of polymers, colloids, and conductive coatings [7]; energy storage and battery analysis [8]; biological analysis and biomedical sensor development [9]; or studies of electrochemical kinetics, reactions, and processes [10]. EIS is therefore a very useful technique that can be used as a biological tool to evaluate the status and variations in RhE models after the application of different test compounds, having already shown to be useful in the assessment of eye irritation/severe eye damage in reconstructed human corneal epithelium models [11].…”