Engineering Activated Carbon via Chemical Vapor Deposition for High-Performance Core-Shell Carbon Anodes in Sodium-Ion Batteries
- Rising demand for sustainable energy storage has renewed interest in sodium-ion batteries (SIBs) as alternative to lithium-ion batteries. Although hard carbon and related materials are common SIB-anodes, the correlation between its structure and ion storage mechanism remains unclear.[1] As shown recently, the pore design is essential to block the formation of excessive solid electrolyte interphase (SEI) and allows the formation of pseudo-metallic clusters inside the pores.[2,3] Adjusting the diameter of the pore entrance, enables a reversible low-potential plateau (< 0.1 V), which significantly enhances the capacity (potentially up to 450-500 mAh/g) compared to graphite (Qtheo = 372 mAh/g) in Li-ion batteries.[2]
Activated carbon (AC) is a low-cost material with abundant micropores and high surface area, making it a promising anode candidate for SIBs. However, its performance is often hindered by structural disorder and excessive SEI-formation. Hence, mitigating active-species loss isRising demand for sustainable energy storage has renewed interest in sodium-ion batteries (SIBs) as alternative to lithium-ion batteries. Although hard carbon and related materials are common SIB-anodes, the correlation between its structure and ion storage mechanism remains unclear.[1] As shown recently, the pore design is essential to block the formation of excessive solid electrolyte interphase (SEI) and allows the formation of pseudo-metallic clusters inside the pores.[2,3] Adjusting the diameter of the pore entrance, enables a reversible low-potential plateau (< 0.1 V), which significantly enhances the capacity (potentially up to 450-500 mAh/g) compared to graphite (Qtheo = 372 mAh/g) in Li-ion batteries.[2]
Activated carbon (AC) is a low-cost material with abundant micropores and high surface area, making it a promising anode candidate for SIBs. However, its performance is often hindered by structural disorder and excessive SEI-formation. Hence, mitigating active-species loss is essential to achieve high specific capacities (> 300 mAh g-1).[3] The aim herein was to investigate the relationship between the properties of the AC and the CVD-conditions required to achieve an efficient SIB-anode.
This study introduces an optimized chemical vapor deposition (CVD) method to modify various, highly porous commercial ACs aiming towards core-shell carbons, consisting of a porous core and a non-graphitic CVD-shell.[3] The ACs were treated via CVD and characterized using a range of techniques including gas physisorption, small-angle x-ray scattering and X-ray diffraction. The electrochemical properties of the different materials, prior and after CVD-coating, were analysed in half cells vs. Na-metal.
After coating, gas physisorption confirmed a significantly lower surface area for the materials. Depending on the porosity of the material, a longer CVD-time was necessary to fully coat the particles. The successful formation of core-shell carbons enables separation of the storage mechanism from SEI-formation. The CVD-process enables precise control over the microstructure of the carbon material, allowing to enhance the reversible Na-storage capacity, e.g., from 107 mAh g-1 to 353 mAh g-1 while significantly reducing initial Coulombic losses by 73%.
The greatly increased low-potential capacity verifies the formation of an electrolyte-tight CVD shell enabling Na-storage in the porosity of the core. The established link between porosity, CVD-parameters, and performance guides optimization for future materials.…


| Autor*innen: | Alain CernyORCiD |
|---|---|
| Koautor*innen: | Johannes Kühn, Paul Alexander AppelORCiD, Tom Boenke, Thomas Abendroth, Holger Althues, Jonas Krug von NiddaORCiD, Stefan Kaskel, Tim-Patrick FellingerORCiD |
| Dokumenttyp: | Posterpräsentation |
| Veröffentlichungsform: | Präsentation |
| Sprache: | Englisch |
| Jahr der Erstveröffentlichung: | 2026 |
| Organisationseinheit der BAM: | 3 Gefahrgutumschließungen; Energiespeicher |
| 3 Gefahrgutumschließungen; Energiespeicher / 3.6 Elektrochemische Energiematerialien | |
| DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Angewandte Physik |
| Freie Schlagwörter: | Carbon; Chemical Vapour Deposition; Sodium-Ion Battery |
| Themenfelder/Aktivitätsfelder der BAM: | Energie |
| Energie / Elektrische Energiespeicher und -umwandlung | |
| Veranstaltung: | Batterieforum 2026 |
| Veranstaltungsort: | Berlin, Germany |
| Beginndatum der Veranstaltung: | 20.01.2026 |
| Enddatum der Veranstaltung: | 23.01.2026 |
| Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
| Datum der Freischaltung: | 13.02.2026 |
| Referierte Publikation: | Nein |

