Quantitative Analysis of Microstructures and Reaction Interfaces on Composite Cathodes in All-Solid-State Batteries Using a Three-Dimensional Reconstruction Technique

Abstract

The composite cathode of an all-solid-state battery composed of various solid-state components requires a dense microstructure and a highly percolated solid-state interface different from that of a conventional liquid-electrolyte-based Li-ion battery. Indeed, the preparation of such a system is particularly challenging. In this study, quantitative analyses of composite cathodes by three-dimensional reconstruction analysis were performed beyond the existing qualitative analysis, and their microstructures and reaction interfaces were successfully analyzed. Interestingly, various quantitative values of structure properties (such as the volume ratio, connectivity, tortuosity, and pore formation) associated with material optimization and process development were predicted, and they were found to result in limited electrochemical charge/discharge performances. We also verified that the effective two-phase boundaries were significantly suppressed to ∼23% of the total volume because of component dispersion and packing issues.

From nanoscale interface characterization to sustainable energy storage using all-solid-state batteries

“…An example is illustrated in Fig. 3c where 3D reconstruction was used to quantify porosity as well as pores interconnectivity within an ASSB 53 . However, any reconstruction method using the FIB would be limited by the spatial resolutions of its detector-a scanning electron microscope (SEM) in this case.…”

Structure Design of Cathode Electrodes for Solid‐State Batteries: Challenges and Progress

“…Moreover, they also quantitatively derived the area of effective two‐phase boundary, which is effective in either ionic conducting or electronic conducting, and found the effective interface was merely ≈23% of the total interface. [ 32 ]…”

“…Reproduced with permission. [ 32 ] Copyright 2018, American Chemical Society. b) SEM images of traditional cathode with secondary particles morphology and single crystalline morphology together with illustration of lithium transport inside the particles.…”

Analysis of Charge Carrier Transport Toward Optimized Cathode Composites for All‐Solid‐State Li−S Batteries

“…elucidated the performance of thick electrode configurations in graphite‐LiCoO 2 solid‐state cells, reporting the tortuous ion transport within the cathode to be limiting at a high areal capacity of about 15.7 mAh ⋅ cm −2 [67] . For oxide cathode active materials, the influence of the microstructure on cell performance has been discussed in depth [68–75] . The analysis of the effective transport properties of battery separators and electrodes clearly led to a deeper understanding of the underlying bottlenecks.…”

“…[67] For oxide cathode active materials, the influence of the microstructure on cell performance has been discussed in depth. [68][69][70][71][72][73][74][75] The analysis of the effective transport properties of battery separators and electrodes clearly led to a deeper understanding of the underlying bottlenecks. Electrochemical and microscopic techniques, in combination with modeling of cathode composites, are established methods to characterize the influence of both ionic and electronic transport properties on the cell performance.…”