Simple surface treatment improves performance of carbon materials for sodium ion battery anodes
Simple surface treatment improves performance of carbon materials for sodium ion battery anodes. Sergio Aina, Blaz Tratnik, Alen Vizintin, Elena Tchernychova, M. Pilar Lobera, Robert Dominko, María Bernechea. Journal of Power Sources, 2024, 610, 234730
Hard carbons are the most extended anode materials for sodium-ion batteries (SIBs); however, they suffer from several limitations such as low stability, poor rate performance and low initial Coulombic efficiency (iCE). Herein, a simple, fast, and low-cost surface treatment at room temperature using short-chain organic molecules: 3-mercaptopropionic acid (MPA), 1,2-ethanedithiol (EDT) and oxalic acid (OxA) has been applied to a hard carbon (C1400).
The carbons treated with sulfur containing molecules (MPA or EDT) exhibit higher capacity (12 % capacity enhancement after 100th cycles at C/10 and 18 % enhancement at 1C vs. C1400). The introduction of these ligands leads to improved micropore blockage, helping in the reversible insertion of Na ions. Moreover, ex-situ X-ray photoelectron spectroscopy (XPS) analyses demonstrate that thiol functional groups promote the formation of favorable NaF and Na2O-rich solid electrolyte interfaces (SEI) leading to and faster sodium diffusion in the plateau region. Additionally, MPA and EDT treatments have been applied to a soft carbon (Vulcan XC-72R) resulting in a substantial 30 % capacity improvement after 100 cycles at 1C.
These results demonstrate the wide applicability of the method as a straightforward and efficient strategy for improving the electrochemical properties of carbon anodes used in SIBs.
Hard carbons are the most extended anode materials for sodium-ion batteries (SIBs); however, they suffer from several limitations such as low stability, poor rate performance and low initial Coulombic efficiency (iCE). Herein, a simple, fast, and low-cost surface treatment at room temperature using short-chain organic molecules: 3-mercaptopropionic acid (MPA), 1,2-ethanedithiol (EDT) and oxalic acid (OxA) has been applied to a hard carbon (C1400).
The carbons treated with sulfur containing molecules (MPA or EDT) exhibit higher capacity (12 % capacity enhancement after 100th cycles at C/10 and 18 % enhancement at 1C vs. C1400). The introduction of these ligands leads to improved micropore blockage, helping in the reversible insertion of Na ions. Moreover, ex-situ X-ray photoelectron spectroscopy (XPS) analyses demonstrate that thiol functional groups promote the formation of favorable NaF and Na2O-rich solid electrolyte interfaces (SEI) leading to and faster sodium diffusion in the plateau region. Additionally, MPA and EDT treatments have been applied to a soft carbon (Vulcan XC-72R) resulting in a substantial 30 % capacity improvement after 100 cycles at 1C.
These results demonstrate the wide applicability of the method as a straightforward and efficient strategy for improving the electrochemical properties of carbon anodes used in SIBs.