Speaker
Description
In recent years, sodium-ion batteries (SIBs) have attracted great attention due to the high demand of resources for large-scale applications [1, 2]. Sodium is one of the most abundant elements in the Earth's crust and is close to lithium in terms of its properties.
Prussian blue (PB) and its analogues, such as Prussian white (PW), are of intense interest as cathode material for SIBS [3-5]. Sodium iron hexacyanoferrate Prussian white (PW) is a commercially available cathode material for sodium-ion batteries. However, the structure of the hexacyanoferrate contains water, and the electrochemical performance of the PW strongly depends on the dehydration level of the material. Moreover, PW electrodes show a rapid capacity decrease, which is argued to be related with interfacial chemical reactions. A protective coating may be applied to suppress or completely prevent such reactions. In this work, we coated μm-sized PW particles with polyaniline (PANI) shell and investigated the effect of drying at increased temperature on PW@PANI material. The PW@PANI material exhibits a discharge capacity of 89.1 mAh g–1 at 85 mA g–1 with a capacity retention of 78.4% over 500 cycles. PW@PANI electrode dried at 140°C demonstrates a stable capacity of up to ≈ 97 mAh g–1 during first 200 cycles at 85 mA g–1, however, its capacity retention over 500 cycles is lower compared to the non-dried PW@PANI electrode. Drying PW@PANI electrodes at 180°C leads to a rapid capacity decrease. For the first time, a comparative study of the PW powder soaked with HCl acid solution used in the synthesis of PW@PANI has been performed and its stable long-term electrochemical performance has been observed.
References
[1] T. Liu [et al.] Environ. Sci. 12 (2019) 1512-1533.
[2] H. Zhang [et al.] Adv. Energy Mater. 13 (2023) 2300149.
[3] X.-Y. Fu [et al.] Rare Met. 44(1) (2024) 34-59.
[4] Y. Bai [et al.] Eur. J. Inorg. Chem. 26 (2023) e202300246.
[5] W.-J. Li [et al.] Small 15 (2019) 1900470.
