Through pyrolysis, lignin can be converted into hard carbon (HC) with a disordered structure and large interlayer spacing, making it a promising precursor for electrodes used in supercapacitors and batteries. To gain a deeper understanding of the charge storage mechanism in lignin-derived HC,  lignin obtained from various wood species and processes was utilized in this study. The impact of different chemical structures of lignin, and the relationship between the microstructure of the resulting HC and its capacitance performance was explored. The electrochemical performance was evaluated  both in aqueous electrolytes and in sodium-ion batteries. A comprehensive chemical analysis of lignin revealed its inherently carbon-rich structure and inter-unit linkages. It was also demonstrated that oxygen-containing groups inhibit the growth and alignment of graphitic layers during carbonization resulting in increased  interlayer spacing. This would facilitate the ion insertion and lead to exceptional rate capability and outstanding cycle life. The pore architectures of the obtained HC were analyzed using N₂ and CO₂ adsorption/desorption, and X-ray scattering techniques. The results showed that the pyrolysis process affects the closure of the micropores, and the unique distribution of these closed pores plays a key role in determining the capacitance. Consequently, the best lignin-derived HC achieved a high reversible specific capacity of 326 mAh g⁻¹ as the anode for sodium-ion batteries. In addition, the galvanostatic charge-discharge curves showed almost symmetrical charge-discharge profiles in aqueous electrolytes, indicating excellent electrochemical reversibility and low internal resistance. Based on the electrochemical evaluations, a probable ‘‘insertion-adsorption’’ charge storage mechanism was proposed to elucidate the effects of lignin chemistry on the morphology and sodium storage behavior of HC. This inspired the concept of designing HC microstructures tailored by the type of wood source for the lignin and the specific chemical modification applied to it.