Advancements in cathode technology, recycling strategies, and market dynamics: A comprehensive review of sodium ion batteries
Hussein Rostami, Johanna Valio, P. Suominen, Pekka Tynjälä, Ulla Lassi
Abstract
The rising demand for sodium-ion batteries (SIBs) in commercial applications emphasizes the importance of meeting commercial criteria. Despite their potential, SIBs encounter challenges related to specific energy, cycling life, and specific power due to the unique characteristics of sodium ions. Design strategies, surface engineering, and structural modifications for cathode materials have been devised to improve the electrochemical performance of SIBs. In SIBs, the energy density primarily depends on the choice of cathode materials. Common cathode materials nowadays include transition metal oxides, polyanionic compounds, and Prussian blue analogs (PBAs). Enhancing these materials through targeted modifications to overcome their limitations is crucial for transitioning them from lab-scale to practical use. However, there are still some challenges to address before cathode materials can be effectively utilized for large-scale energy storage in SIBs. Recycling spent SIBs poses significant economic and environmental challenges, particularly compared to lithium-ion batteries (LIBs). Despite progress in cathode materials, thorough environmental assessments and detailed inventory data are lacking for SIBs. The early stage of their development restricts metal recycling in SIBs, underscoring the significance of end-of-life treatment. Pyrometallurgy and hydrometallurgy are commonly employed for metal recovery, with pyrometallurgy favored for SIBs due to reduced sodium evaporation risks. The marketing and commercialization trends in SIBs reflect the growing demand for renewable energy solutions. SIBs, with their potential for grid-scale energy storage, are expected to support the expansion of renewable energy infrastructure. However, overcoming technological challenges and reducing costs are key to SIB commercialization. In this regard, startups are playing a significant role in advancing SIB technologies for large-scale energy storage applications. The collaboration between companies and advancements in manufacturing facilities are driving SIB production, marking substantial progress towards commercialization. This paper aims to provide a comprehensive review of the current research and advancements in SIB technology.