Technical Analysis and Electrochemical Evaluation of a Sodium-Ion Battery System Based on Boron-Doped Hard Carbon Anodes, Prussian Blue Analogue Cathodes, and Non-Flammable Green Matrix Electrolytes

The rapid scaling of grid energy storage and electric mobility necessitates low-cost, sustainable, and inherently safe energy storage technologies beyond conventional lithium-ion systems. Sodium-ion batteries (SIBs) present a compelling alternative due to the geographic abundance and low cost of sodium resources. However, widespread commercialization is hindered by large ionic radius constraints, slow intercalation kinetics, and safety hazards associated with volatile organic electrolytes. This paper presents a comprehensive technical analysis and electrochemical evaluation of a full-cell SIB architecture integrating boron-doped hard carbon (B-HC) anodes, low-defect Prussian Blue Analogue (PBA) cathodes, and a non-flammable green matrix electrolyte (GME) composed of bio-derived ionic liquids and deep eutectic solvents. Boron doping enhances the interlayer spacing and electronic conductivity of the hard carbon matrix, facilitating rapid Na+ diffusion and high reversible capacity. The low-defect PBA cathode provides robust structural stability against volume expansion during cycling. Electrochemical impedance spectroscopy and galvanostatic charge-discharge simulations confirm high initial coulombic efficiency, superior rate capability, and exceptional thermal stability under abusive overcharge regimes. This integrated material design offers a viable, eco-friendly, and cost-effective paradigm for next-generation stationary energy storage.