State of Charge Estimation of Sodium Ion Battery under different Operating Conditions using Cascade Forward Backpropagation Algorithm

Sodium ion battery (SIB) technology is a promising battery technology for future energy storage systems. Due to sodium's abundance in nature and lower cost, it can be a good alternative to current Lithium ion battery (LIB) technology. The Na _0.7 Ni _0.3 Mn _0.59 Co _0.1 Cu _0.01 O ₂ cathode material was synthesized using sol gel method. The sodium ion battery was fabricated and tested resulting in the maximum discharge capacity of 150 mAhg ^-1 at 0.1C. The transition metal oxide SIB discharge profile contains many voltage plateaus compared to its lithium counterpart, thus necessitate the determination of the state of charge estimation for SIBs. The fabricated SIB was discharged at two different current rates (0.5C & 1C) and three different temperatures (30°C, 45°C & 55°C). These experimental results of discharge cycles were used to train the Cascade Forward Backpropagation (CFB) algorithm and used for the estimation of State of Charge (SOC) of the SIB battery. The result showed a very good estimation of SOC for SIBs.