Tuning the porosity of hard carbons elaborated from sucrose

• Published in: The Journal of physics and chemistry of solids 2024-08, Vol.191, p.112013, Article 112013
• Main Authors: Raspado, L., Speyer, L., Bolmont, M., Cahen, S., Fontana, S., Hérold, C.
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Hard carbons; Na-ion battery; Pressure effect; Sodium intercalation mechanism; Textural properties adjustment
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2024.112013

Hard carbons are among the most promising anode materials for Na-ion batteries (NIB) and are extensively studied. Nevertheless, it is still necessary to decipher the electrochemical intercalation behavior of sodium which is still under debate in the literature. Here, we present an innovating approach for elaborating hard carbon from simple sucrose precursor. It consists in a low-temperature pyrolysis at 500 °C under controlled argon pressure, followed by low-temperature carbonization. Using complementary characterization techniques (XRD, Raman, TEM, gas adsorption, SAXS) and galvanostatic electrochemical measurements, we show that this elaboration route allows the possibility to control and modify the porosity of the hard carbons without any modification of the structure of the material. This work leads us to assign the low potential plateau to the development of quasi-metal clustering of sodium into narrow porosity developed tuned thanks to the pyrolysis under pressure. [Display omitted] •We developed an original method of hard carbons elaboration by pyrolysis of carbon precursor under controlled pressure.•We show the possibility to finely control the porosity of hard carbons without modifying its structure or chemistry.•Adjustment of the porosity allows the optimization ofelectrochemical properties of hard carbons for sodium-ion batteries.•Weclearly attribute the low potential plateau to quasi-metal clustering in developed ultramicroporosity.