||Sodium‐ion batteries (SIBs) have received much attention for large‐scale energy storage devices as economical and high energy alternatives to lithium‐ion batteries in the last few years. Graphite is the most common anode materials of commercial lithium-ion batteries, but it has been reported to show very low capacity by unfavorable intercalation of sodium-ion when used as the anode for SIBs. In case of hard carbon, capable of storing ions by pseudocapacitive mechanism can be used as the anode for SIBs. However, the major challenge of the hard carbon anode is the insufficient cycle performance. Despite much research about the capacity reduction problem, the reason was not clearly confirmed. In this study, we investigate how kinetics or thermodynamics properties affect to capacity fading of the hard carbon anode for SIBs. In addition, this research indicates good direction for improved cycle performance of hard carbon.