Over the past few decades, Lithium-ion batteries (LIBs) have been extensively researched and commercialized, becoming the dominant energy storage technology. However, challenges such as limited lithium reserves and high production costs persist. To address these issues, Sodium-ion batteries (SIBs) are being explored as a promising alternative, utilizing sodium—an abundant and cost-effective resource primarily sourced from seawater. Despite these advantages, the performance of sodium-ion batteries remains suboptimal. This study aims to explore innovative materials, including electrode materials and electrolytes, and state-of-the-art characterization techniques being developed to enhance the performance of SIBs. This review provides an overview of the fundamental principles and mechanisms of sodium-ion batteries, such as ion transport and charge storage processes, which are crucial for optimizing their design. It also investigates the role of advanced computational methods to predict and improve battery performance, further bridging the gap between experimental research and practical applications. Additionally, it examines emerging research trends and future directions for industrial development in the sodium-ion battery field.