Solid-state batteries have been attracting wide attention for next generation energy storage devices due to the probability to realize higher energy density and superior safety performance compared with the state-of-the-art lithium ion batteries. However, there are still intimidating challenges for developing low cost and industrially scalable solid-state batteries with high energy density and stable cycling life for large-scale energy storage and electric vehicle applications. This review presents an overview on the scientific challenges, fundamental mechanisms, and design strategies for solid-state batteries, specifically focusing on the stability issues of solid-state electrolytes and the associated interfaces with both cathode and anode electrodes. First, we give a brief overview on the history of solid-state battery technologies, followed by introduction and discussion on different types of solid-state electrolytes. Then, the associated stability issues, from phenomena to fundamental understandings, are intensively discussed, including chemical, electrochemical, mechanical, and thermal stability issues; effective optimization strategies are also summarized. State-of-the-art characterization techniques and in situ and operando measurement methods deployed and developed to study the aforementioned issues are summarized as well. Following the obtained insights, perspectives are given in the end on how to design practically accessible solid-state batteries in the future.

Approaching Practically Accessible Solid-State Batteries: Stability Issues Related to Solid Electrolytes and Interfaces

This review paper discusses the influence of morphology and crystallographic structure on gas-sensing characteristics of metal oxide conductometric-type sensors. The effects of parameters such as film thickness, grain size, agglomeration, porosity, faceting, grain network, surface geometry, and film texture on the main analytical characteristics (absolute magnitude and selectivity of sensor response (S), response time (τres), recovery time (τrec), and temporal stability) of the gas sensor have been analyzed. A comparison of standard polycrystalline sensors and sensors based on one-dimension structures was conducted. It was concluded that the structural parameters of metal oxides are important factors for controlling response parameters of resistive type gas sensors. For example, it was shown that the decrease of thickness, grain size and degree of texture is the best way to decrease time constants of metal oxide sensors. However, it was concluded that there is not universal decision for simultaneous optimization all gas-sensing characteristics. We have to search for a compromise between various engineering approaches because adjusting one design feature may improve one performance metric but considerably degrade another.

The role of morphology and crystallographic structure of metal oxides in response of conductometric-type gas sensors

Nasicons (sodium super ion conductors) are a class of solid electrolytes. Their structure, compositional diversity, evolution, and applications are reviewed. A wide range of materials is considered based on crystalline and glassy Nasicon compositions.

A wide-ranging review on Nasicon type materials

Review of Electrochemical Hydrogen Sensors

The subject of sol−gel electrochemistry is introduced, starting with a brief account of milestones in its evolution. Then, the types of sol−gel materials that are useful for electrochemistry are presented, followed by a description of recent advances in the various fields of sol−gel electrochemistry. Modified electrodes, solid electrolytes, electrochromic devices, and corrosion protection coatings are described. Emerging fields such as RuO2 supercapacitors and electrochemical synthesis of sol−gel precursors are also addressed.

A. Ahmad

Papers

Dependence of the properties of Nasicons on their composition and processing

Characterization of protonically exchanged NASICON

Sol-gel processing of NASICON thin-film precursors

Influence of water on the electrochemical response of a bonded nasicon protonic conductor

Bonded solid protonic conductor/platinum electrochemical cells