Advanced Characterization Techniques for Sulfide‐Based Solid‐State Lithium Batteries

Abstract

Solid‐state lithium batteries with sulfide solid electrolytes have attracted extensive attention as next‐generation secondary batteries with high energy and power densities because sulfide solid electrolytes possess several advantages over liquid electrolytes, such as their nonfluidity, single‐ion conductivity, and low flammability. However, they still face barriers that limit their practical application, such as the (electro)chemical decomposition of solid electrolytes, mechanical degradation at interfaces, dendrite growth of lithium metal, and slow lithium diffusion in active materials. These limitations are dynamic phenomena that occur during charge and discharge reactions. The dynamic behavior inside a battery must be understood to rationally design high‐performance solid‐state lithium batteries. For this purpose, operando and in situ analyses, which analyze devices under working conditions, are promising characterization techniques. This review focuses primarily on the four issues mentioned above for bulk‐type solid‐state lithium batteries with sulfide solid electrolytes. The current status and future prospects of advanced characterization techniques, such as X‐ray photoelectron spectroscopy, time‐of‐flight secondary ion mass spectrometry, transmission electron microscopy, and X‐ray computed tomography, for addressing these issues are reviewed.

Design of Cathode Coating Using Niobate and Phosphate Hybrid Material for Sulfide-Based Solid-State Battery

“…There are several reports regarding the stable operation of a 5 V class cathode, such as LiNi 0.5 Mn 1.5 O 4 , with Li 3 PO 4 coating in an ASSB cathode. , Moreover, new coating materials of NASICON-type LiZr 2 (PO 4 ) 3 , which display a high durability and comprise transition metals other than Nb, have also been recently proposed; this approach will promote the use of hybrid materials. From a wider viewpoint of interface design, the combination of various SE materials and the surface properties of the oxide cathode active material such as the defects, impurities, and morphology are also important. − A more precise design of the coating materials, processes, and analyses is required to improve the cell performance of ASSBs using sulfide-based SE …”

“…58−60 A more precise design of the coating materials, processes, and analyses is required to improve the cell performance of ASSBs using sulfide-based SE. 61…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…The advanced characterisation techniques used for sulfide-based solid state lithium batteries was presented by Nomura and Yamamoto. 220 This review cited 177 references and discussed the problems associated with lithium ion batteries including their electrochemical decomposition, mechanical degradation at interfaces, dendrite growth of lithium, slow Li diffusion, etc. The techniques used to investigate these phenomena included XPS, TOF-SIMS, TEM and X-ray computed tomography were all discussed.…”

Visualizing asymmetric phase separation driven by surface ionic diffusion in lithium titanate

“…Conversely, operando analyses are preferred for understanding the nonequilibrium phase transition behaviour during Li insertion and extraction. 10,11 Furthermore, the effect of surfaces and grain boundaries on the phase transition and Li diffusion kinetics is yet to be clari-ed. Most previous studies have analyzed average bulk information using material characterization techniques such as macroscopic electrochemical measurements, neutron/X-ray diffraction, and nuclear magnetic resonance, and/or they have explored the bulk and ideal Li 4 Ti 5 O 12 /Li 7 Ti 5 O 12 interfaces using theoretical calculations.…”

“…Conversely, operando analyses are preferred for understanding the nonequilibrium phase transition behaviour during Li insertion and extraction. 10,11…”