In Situ Nitrogen Retention of Carbon Anode for Enhancing the Electrochemical Performance for Sodium‐Ion Battery

Abstract Retaining nitrogen for polyacrylonitrile (PAN) based carbon anode is a cost‐effective way to make full use of the advantages of PAN for sodium‐ion batteries (SIBs). Here, a simple strategy has been successfully adopted to retain N atoms in situ and increase production yield of a novel composite PAZ by mixing 3 wt % of zinc borate (ZB) with poly (acrylonitrile‐co‐itaconic acid) (PANIA). Among the prepared carbonised fibre (CF) samples, PAZ‐CF‐700 maintains the highest N content, retaining 90 % of the original N from PANIA. It represents the highest capacity storage contribution (80.55 %) and the lowest impedance R ct (117 Ω). Consequently, the specific capacity increases from 60 mAh g −1 of PANIA‐CF‐700 to 190 mAh g −1 of PAZ‐CF‐700 at a current density of 100 mA g −1 . At the same time, PAZ‐CF‐700 exhibits a good rate performance and excellent long‐term cycling stability with a specific capacity of 94 mAh g −1 after 4000 cycles at 1.6 A g −1 .