Impact of Fluorine content on the Stability and Electronic properties of Sodium Lithium Manganese Oxide Cathode materials for Sodium-ion batteries

Abstract

Sodium-ion batteries are emerging as a promising alternative to traditional rechargeable batteries, such as lithium-ion and lead-acid batteries. One of the most significant advantages of sodium-ion technology is that it utilizes materials that are not only cost-effective but also environmentally friendly. The raw materials needed to produce sodium-ion batteries are widely available, leading to reduced supply chain risks and potential price volatility often associated with lithium resources. Furthermore, the transition in energy storage mechanisms and manufacturing techniques from lithium-ion batteries is seamless since the two technologies facilitate a relatively smooth integration into existing production methods, which can lead to substantial cost savings for manufacturers. As the demand for energy storage continues to grow, the shift towards sodium-ion technology represents not just an innovation but also a practical move in battery production. Among the various cathode materials being researched for sodium-ion batteries, sodium lithium manganese oxides (NLM) have garnered attention for their potential. They exhibit good capacity and energy density; however, one of the critical challenges in their application is the Jahn-Teller distortion. This phenomenon occurs during cycling due to the changes in the valence state of manganese within the structure. As the battery operates, this distortion can lead to irreversible phase changes, compromising the structural integrity of the material and diminishing its capacity over time. To address these challenges, we investigate the role of fluorine content in enhancing the structural stability and electrochemical characteristics of (Co, F)-co-doped NLM cathode materials. By incorporating fluorine into the material's composition, we reveal that the effect of Jahn-Teller distortion can be mitigated. This modification not only helps preserve the capacity of the battery over multiple cycles but also improves the overall electrochemical performance of the cathodes. The results underscore the effectiveness of co-doping strategies, combining both cationic (like cobalt) and anionic (like fluorine) ions, to enhance the properties of electrode materials. This approach could hold the key to unlocking better performance in sodium-ion batteries, ultimately contributing to the development of next-generation energy storage solutions that are more efficient and sustainable. In summary, the advances in sodium-ion battery technology signal a significant step forward in energy storage systems. By tackling the limitations of existing materials and optimizing their composition, researchers are paving the way for viable alternatives to lithium-ion technology, thereby promoting a more sustainable and cost-effective energy future.