Mesoporous Weaved Turbostratic Nanodomains Enable Stable Na+ Ion Storage and Micropore Filling is Revealed to be More Unsafe than Adsorption and Deintercalation

Advanced wave-shape non-graphitizable carbon sheets are derived, comprising mesoporous weaved turbostratic micropore enabled stable Na+ ion storage. The non-graphitizable amorphous characteristics are determined from the obtained two broad diffraction peaks at 22.7 degrees and 43.8 degrees. The observed D-band at 1325 cm(-1 )and G-band at 1586 cm(-1) confirm the disordered graphitic structure, attributed to the measured specific surface area of 54 m(2) g(-1). Mesoporous weaved wave-shape carbon sheet architecture is confirmed by surface morphological studies, showing lattice fringes of disordered graphitic structures and dispersed ring patterns for the non-crystalline characteristics. The predominant stable redox peak at 0.014 V/0.185 V and the broader rectangular shape between 0.9 and 0.15 V depict the adsorption-micropore filling mechanism. The mesoporous hard carbon sheet delivers discharge-charge capacities of 450/311 mAh g(-1) (1st cycle) and 263/267 mAh g(-1) (250th cycle) at 25 mA exhibiting a superior anode for sodium-ion batteries. Besides, in situ multimode calorimetry results disclose that the micropore filling Na+ ion storage shows a higher released total heat energy of 721 J g(-1) than the adsorption (471 J g(-1)). Ultimately, differential scanning calorimetry analysis of micropore filling Na+ ion storage (discharged state at 0.01 V) has revealed a predominant exothermic peak at 156 degrees C with the highest released total heat energy of 2183 J g(-1) compared to adsorption (553 J g(-1)) and deintercalation (85 J g(-1)), indicating that micropore filling status is more unsafe than the adsorption and deintercalation for SIBs.

Automated summary

This study focused on advanced wave-shape non-graphitizable carbon sheets for stable Na+ ion storage, demonstrating the amorphous characteristics and specific surface area through diffraction peaks and Raman spectroscopy. The mesoporous weaved architecture showed stable redox peak and superior discharge-charge capacities, indicating the potential as an anode for sodium-ion batteries. In situ calorimetry results highlighted the higher total heat energy released in micropore filling Na+ ion storage compared to adsorption, and differential scanning calorimetry analysis revealed the safety concerns of micropore filling status for SIBs.