Pseudocapacitive Heteroatom‐Doped Carbon Cathode for Aluminum‐Ion Batteries with Ultrahigh Reversible Stability

Abstract

Aluminum (Al)‐ion batteries have emerged as a potential alternative to conventional ion batteries that rely on less abundant and costly materials like lithium. Nonetheless, given the nascent stage of advancement in Al‐ion batteries (AIBs), attaining electrode materials that can leverage both intercalation capacity and structural stability remains challenging. Herein, we demonstrate a C3N4‐derived layered N,S heteroatom−doped carbon, obtained at different pyrolysis temperatures, as a cathode material for AIBs, encompassing the diffusion−controlled intercalation and surface‐induced capacity with ultrahigh reversibility. The developed layered N,S‐doped corbon (N,S‐C) cathode, synthesized at 900 °C, delivers a specific capacity of 330 mAh g−1 with a relatively high coulombic efficiency of ~85% after 500 cycles under a current density of 0.5 A g−1. Owing to its reinforced adsorption capability and enlarged interlayer spacing by doping N and S heteroatoms, the N,S‐C900 cathode demonstrates outstanding energy storage capacity with excellent rate performance (61 mAh g−1 at 20 A g−1) and ultrahigh reversibility (90 mAh g−1 at 5 A g−1 after 10 000 cycles).