Structural degradation mechanisms and modulation technologies of layered oxide cathodes for sodium‐ion batteries

Abstract

Renewable energies, such as solar and wind, have been explored and widely applied for alleviating problems associated with the depletion of fossil fuel resources and environmental pollution. The intermittent and fluctuating features of these renewable energies require development of efficient energy storage and conversion systems. Sodium‐ion batteries (SIBs) are considered one of the most promising candidates for large‐scale energy storage due to the low cost and earth abundance of sodium resources. A major challenge for the practical application of SIBs is the development of appropriate cathodes with high energy densities and cycling stabilities. Layered oxide cathodes have received significant attention because of their relatively simple synthetic routes and high capacities stemming from their layered structures. However, they often suffer from moisture sensitivity and structural degradation upon repeated Na+ insertion/extraction, leading to severe performance fading. This review summarizes and discusses the degradation mechanisms of these layered oxide cathodes and modulation strategies for addressing the stability issues. Understanding the mechanisms behind structural instability would provide better insight for improving SIBs' cathode materials, which has critical implications for the designs and applications of SIBs as renewable energy systems.

Developing High‐Performance Metal Selenides for Sodium‐Ion Batteries

“…[ 10–13 ] Significantly, Prussian blue analogous, layered transition metal oxides, and polyanionic compounds have almost achieved commercial application in SIBs. [ 14–16 ] Nevertheless, for the anode materials, the most successful graphite anode for LIBs cannot be directly used for SIBs in carbonate ester electrolytes. [ 17,18 ] Therefore, the development of commercially available SIB anodes is equally critical and urgent.…”

Bismuth nanoparticles embedded in a carbon skeleton as an anode for high power density potassium-ion batteries

“…1 One of the effective strategies is to increase the share of renewable clean energy (such as wind, solar, and geothermal resources) in the electric energy structure. [2][3][4][5][6] However, renewable clean energy is generally intermittent, so its development closely depends on large-scale energy storage/conversion systems. [7][8][9] Recently, potassium-ion batteries (PIBs) have been considered as promising candidates for this purpose due to the high abundance of potassium resources and low redox potential of K + /K in an organic electrolyte (À2.93 V vs. the standard hydrogen electrode).…”

Recent achievements of free‐standing material and interface optimization in high‐energy‐density flexible lithium batteries

“…[ 1,2 ] Among them, lithium‐based batteries (LiBs) with high energy density and safety are appealing for flexible electronics but are subject to the inherent rigidity of components and structural design. [ 3–5 ] It is worth noting that the electrodes and active materials will peel off from the metallic current collectors under the condition of extreme mechanical deformation when the employ of rigid metal current collectors, fragile inorganic electrode materials, [ 6,7 ] and using traditional stacked configurations, [ 8 ] then resulting in increased interphase electrical contact resistance and decreased battery capacity. Furthermore, relative displacement or delamination among adjacent components of LiBs is subjected to bending strain, which will lead to rapid performance degradation and short circuit in the worst‐case scenario.…”