Review of the Developments and Difficulties in Inorganic Solid-State Electrolytes

Abstract

All-solid-state lithium-ion batteries (ASSLIBs), with their exceptional attributes, have captured the attention of researchers. They offer a viable solution to the inherent flaws of traditional lithium-ion batteries. The crux of an ASSLB lies in its solid-state electrolyte (SSE) which shows higher stability and safety compared to liquid electrolyte. Additionally, it holds the promise of being compatible with Li metal anode, thereby realizing higher capacity. Inorganic SSEs have undergone tremendous developments in the last few decades; however, their practical applications still face difficulties such as the electrode–electrolyte interface, air stability, and so on. The structural composition of inorganic electrolytes is inherently linked to the advantages and difficulties they present. This article provides a comprehensive explanation of the development, structure, and Li-ion transport mechanism of representative inorganic SSEs. Moreover, corresponding difficulties such as interface issues and air stability as well as possible solutions are also discussed.

Y-Doped LiZr2(PO4)3 in a PVDF-HFP Composite Electrolyte for Solid-State Li-Metal Batteries

“…It can be seen from Figure (a) that the overall resistance (∼29 kΩ) of the sample is dominated by the grain boundary resistance (∼24.5 kΩ). Such high grain boundary resistance in the sample may be due to the poor densification, microcracks, and impurity phase segregation at grain boundaries. ,− The lithium-ion conductivity in NASICON-type electrolytes is affected by the grain boundary and intra-/intergrain microcracks, which prevent the rapid movement of lithium ions between the grains. Furthermore, it is well recognized that the microcracks found in this specimen negatively affect the lithium-ion conductivity. , …”

Technological Advances and Market Developments of Solid-State Batteries: A Review

“…Additionally, LATP has a low tendency to form dendrites, which can improve the safety and cycle life of the battery. However, LATP is relatively expensive and has a lower ionic conductivity than LLZO [ 29 , 30 ].…”