Biomimetic mineralization preparation of porous carbon materials for sodium ion storage

Abstract

Biomimetic mineralization serves as an efficient approach for designing and preparing nanomaterials. In this work, we developed a bioinspired mineralization approach under freezing conditions to fabricated sodium alginate (SA)/NaHCO₃ precursors with a sophisticated biomineralized structure. Based on this, a novel spring mattress-like porous carbon (SMPC) was synthesized after carbonization and removal of inorganic crystals. Benefiting from their open framework, large surface area, and enlarged interlayer spacing of graphitized nanocrystallites, the obtained SMPC exhibited an obvious boost in sodium storage performance. Among the synthesized variants, SMPC-3 exhibited the most balanced porous architecture, leading to a high reversible capacity of 374 mAh g⁻¹ and outstanding cycling stability with 121 mAh g⁻¹ retained after 3000 cycles at 2 A g⁻¹. When paired with activated carbon in a sodium-ion hybrid capacitor, the device delivered an energy density of 105 Wh kg⁻¹ at a power density of 200 W kg⁻¹ and retained 91.1 % of its capacity over 10,000 cycles. This work presents a straightforward and environmentally friendly approach towards the development of highly efficient carbon anodes suited for advanced sodium-ion energy storage systems.