Tuning Bi–C 3D architecture of Bi/carbon nanofibres for high power and cycling stability SIBs anodes

Carbon-based materials are frequently employed as anodes for sodium-ion batteries (SIBs) due to their structural stability. This stability enables them to withstand the repeated intercalation and de-intercalation of Na⁺ during the charge-discharge cycles without significant deformation or performance degradation, thus ensuring the long-term operation of SIBs. However, high energy density and high power density have been the goals of SIBs. Herein, an electrode material combining bismuth (Bi) and carbon nanofibres (CNFs) was prepared. Bi was sputtered on CNFs in the form of nanodots. CNFs-50Bi has a high initial coulombic efficiency of 98.31% at 0.1 A/g and superior rate capability of 186 mAh/g as an anode at 3 A/g. CNFs mitigate volume expansion during alloying and maintain batteries stability. The incorporation of Bi metal into the battery configuration serves to augment the overall capacity and enhance the rate capability. Therefore, the doping of suitable quantities of Bi metal materials may facilitate the development of high-performance carbonaceous materials as anodes for SIBs.