Enhanced potassium storage of two dimensional Sb2Se3/MXene@NC as an anode material for potassium-ion batteries

Potassium ion batteries (PIBs) have drawn attention owing to their abundant resources and similar properties lithium-ion batteries. In recent studies, there has been a focus on exploring transition metal selenides as potential anode materials for PIBs due to their high theoretical capacities. Particularly, Sb2Se3 has been regarded as a viable anode material in PIBs due to its high theoretical capacity of 670 mAh g−1, coupled with the natural abundance and chemical stability of its constituent elements. However, Sb2Se3 suffers considerable volume expansion during discharge/charge processes, which can deform the structure of the electrode. Furthermore, Sb2Se3 undergoes poor cycling performance because of its low electrical conductivity. In this work, a novel Sb2Se3/MXene@NC composite was fabricated to tackle these problems. The electrostatic attraction between negatively charged MXene and positively charged Sb3+ enabled Sb2Se3 particles to be homogenously anchored on the surface of MXene, boosting electrical conductivity, mechanical stability, and flexibility of the Sb2Se3 electrode. Sb2Se3/MX@NC showed a high discharge capacity of 484.6 mAh g−1 after 100 cycles at 0.1 A g−1 in 0.01–3.0 V. At a high current density of 1.0 A g−1, the excellent long-term cycle life was achieved with a discharge capacity of 290.3 mAh g−1 after 1000 cycles.