Influence of Electrode Thickness and Electrolyte Composition on SEI Formation and Cycle Stability in Binder-Free Hard Carbon Anodes for Na-Ion Batteries
Abstract
Hard carbon self-supported electrodes (HC SSEs) have gained significant interest as an alternative to classical binder-based anode materials for sodium-ion batteries (SIBs), eliminating the need for binders, solvents, conductive carbon, and current collectors. In this work, we investigate the impact of HC thickness and macroporosity, as well as the presence/absence of an electrolyte additive, on the formation of the solid electrolyte interphase (SEI) and electrochemical performance. Three cellulose-based filter paper (FP) precursors with different thicknesses were used to prepare HC SSEs through a pyrolysis process at 1500 °C, and then these were compared with an HC SSE obtained from commercial carbon fabric. The results highlight the importance of appropriate structural, morphological, porosity, and surface chemical properties of the materials to achieve high initial Coulombic efficiency (up to 93%) and high reversible capacity (up to 328 mAh g -1 at 37.2 mA g -1 ). However, the cycle stability was greatly impacted by the electrode thickness/macroporosity and the electrolyte additive. In NaPF6 without fluoroethylene carbonate (FEC) additive, the maximum number of cycles (50) was obtained for the thinnest electrode (79 µm), while rapid fading (after ≈1-5 cycles) was observed for electrode thicknesses >185 µm. By using the FEC additive, the fading is mitigated and cycling stability (100 cycles) is reached for all the electrodes, except the commercial one (5 cycles), due to its highest thickness (1042 µm). The improvement in stability could be explained by the buildup of a thin homogeneous inorganic-rich SEI containing more NaF in the presence of FEC, which is more stable, protective, and electronically conductive.
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BibTeX
@article{trinh2026influence,
title = {{Influence of Electrode Thickness and Electrolyte Composition on SEI Formation and Cycle Stability in Binder-Free Hard Carbon Anodes for Na-Ion Batteries}},
author = {Tien-Nguyen-Khoi Trinh and Adrian Beda and Samar Hajjar-Garreau and Cyril Vaulot and Camélia Matei Ghimbeu},
journal = {ACS Applied Materials \& Interfaces},
year = {2026},
month = may,
doi = {10.1021/acsami.5c25017},
eprint = {2610.06253},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05772957v1},
note = {CC BY-SA 4.0},
}
RIS
TY - JOUR
TI - Influence of Electrode Thickness and Electrolyte Composition on SEI Formation and Cycle Stability in Binder-Free Hard Carbon Anodes for Na-Ion Batteries
AU - Tien-Nguyen-Khoi Trinh
AU - Adrian Beda
AU - Samar Hajjar-Garreau
AU - Cyril Vaulot
AU - Camélia Matei Ghimbeu
PY - 2026
DA - 2026/05/28
JO - ACS Applied Materials & Interfaces
DO - 10.1021/acsami.5c25017
UR - https://hal.science/hal-05772957v1
AB - Hard carbon self-supported electrodes (HC SSEs) have gained significant interest as an alternative to classical binder-based anode materials for sodium-ion batteries (SIBs), eliminating the need for binders, solvents, conductive carbon, and current collectors. In this work, we investigate the impact of HC thickness and macroporosity, as well as the presence/absence of an electrolyte additive, on the formation of the solid electrolyte interphase (SEI) and electrochemical performance. Three cellulose-based filter paper (FP) precursors with different thicknesses were used to prepare HC SSEs through a pyrolysis process at 1500 °C, and then these were compared with an HC SSE obtained from commercial carbon fabric. The results highlight the importance of appropriate structural, morphological, porosity, and surface chemical properties of the materials to achieve high initial Coulombic efficiency (up to 93%) and high reversible capacity (up to 328 mAh g -1 at 37.2 mA g -1 ). However, the cycle stability was greatly impacted by the electrode thickness/macroporosity and the electrolyte additive. In NaPF6 without fluoroethylene carbonate (FEC) additive, the maximum number of cycles (50) was obtained for the thinnest electrode (79 µm), while rapid fading (after ≈1-5 cycles) was observed for electrode thicknesses >185 µm. By using the FEC additive, the fading is mitigated and cycling stability (100 cycles) is reached for all the electrodes, except the commercial one (5 cycles), due to its highest thickness (1042 µm). The improvement in stability could be explained by the buildup of a thin homogeneous inorganic-rich SEI containing more NaF in the presence of FEC, which is more stable, protective, and electronically conductive.
SN - 1944-8244
SN - 1944-8252
ER -