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Yoon et al. Energy Mater 2024;4:400063 https://dx.doi.org/10.20517/energymater.2023.146 Page 11 of 30

[82]
and the current collector. Coquil et al. reported ternary ZnSnSb as a new LIB anode material [Figure 8E] .
2
The ZnSnSb anode exhibited a reversible capacity of 615 mAh g with a capacity retention of 84.2% after
-1
2
-1
200 cycles when evaluated galvanostatically at a current rate of 252 mA g ; this high electrochemical
performance is attributable to the distinctive quasi-topotactic reaction mechanism associated with ZnSnSb
2
during lithiation/delithiation. Su et al. synthesized a NiSb alloy embedded in N-doped carbon (NiSb/C) to
enhance the electrochemical performance of Sb-based anodes for LIBs . The NiSb/C anode exhibited good
[83]
cycling stability and high rate performance, with the elemental Ni suppressing volume expansion and the
N-doped carbon serving as a conductive network with sufficient active sites. Consequently, the NiSb/C
anode demonstrated a reversible capacity of 426 mAh g after 450 cycles at a current rate of 2 A g . In short,
-1
-1
carbon-based composite materials effectively suppress volume expansion and improve electron/ion
diffusion characteristics, resulting in enhanced cycling stability and rate capabilities. Alloy materials have
also been reported to exhibit less volume expansion during charging and discharging owing to their unique
insertion or conversion reaction mechanisms. Regarding the electrolyte, the FEC additive was found to be
essential. An unprecedented LiFSI salt was applied to an Sb anode, and its performance was evaluated.
Recent LIB studies have transcended simple approaches. Instead of focusing on a single breakthrough,
researchers have reported significant performance enhancements by combining multiple effective
improvements. This trend highlights the need to engineer complex and advanced anode materials for next-
generation LIBs. Regarding the electrolyte, the FEC additive was found to be essential, and a promising
LiFSI salt was evaluated with the Sb-based anode. Table 2 summarizes recent advancements in Sb-based LIB
anodes.

Sb-based SIB anodes
Sb has been extensively researched as a high energy density SIB anode material due to its high Na-storage
capacity (Na Sb: 660 mAh g ) and appropriate operating voltage (0.3-0.7 V vs. Na /Na). However, Sb
+
-1
3
anodes exhibit drawbacks similar to those of LIBs, including the formation of unstable SEI layers, significant
volume changes (~291%), and sluggish charge transfer during discharging and charging, resulting in poor
cycling stability. To address these issues, recent advances in SEI layer control, structural control, and
composite/alloy formation have been proposed for Sb-based anodes for SIBs.

Electrolyte additives significantly affect the formation of a stable SEI layer, which is closely related to the
electrochemical performance of the Sb anode [72,89,90] . Lu et al. investigated the surface structure, composition,
and electrochemical performance of Sb-based anodes (SiC-Sb-C) in FEC-free and FEC-containing
electrolytes using XPS, Fourier transform infrared spectroscopy (FTIR), EIS, and electrochemical
characterization techniques [Figure 9A] . Carbonate solvents (EC and DEC) gradually decompose on the
[89]
SiC-Sb-C particle surface in the FEC-free electrolyte to form an SEI layer composed of Na CO , ROCO Na,
2
3
2
and RONa units. The precipitate layers formed from these salts are generally loose, forming thick SEI layers.
FEC-containing electrolyte is more reactive than EC or DEC-containing electrolyte; it decomposes first on
the particle surface to form a dense and thin SEI layer composed of fluorine (F)-containing salts, such as
NaF, F-ROCO Na, and F-RONa. Although a F-containing SEI film can inhibit the decomposition of EC and
2
DEC to a certain extent, EC and DEC still decompose along with FEC at low potentials
(below 0.5 V vs. Na /Na), resulting in the formation of a double-layer SEI film. The formation of a dense
+
and thin double-layer SEI film improves the electrochemical performance of the Sb anode. Bian et al.
investigated the effect of the FEC additive on the Sb anode for SIBs [Figure 9B] . The optimal
[72]
concentration of FEC (10 vol%) provides a stable and NaF-rich SEI layer that alleviates Sb volume changes
and inhibits continuous electrolyte decomposition. Consequently, the microsized Sb anode with an FEC-
containing electrolyte exhibited a reversible capacity of 540 mAh g with a retention of 85.3% after 150
-1
cycles at 200 mA g . Bodenes et al. revealed the role that binders play in determining the thickness,
-1
homogeneity, and chemical composition of the SEI layer formed on the surface of the Sb anode in a SIB