A high‐energy‐density long‐cycle lithium–sulfur battery enabled by 3D graphene architecture

Abstract Lithium–sulfur (Li–S) battery is attracting increasing interest for its potential in low‐cost high‐density energy storage. However, it has been a persistent challenge to simultaneously realize high energy density and long cycle life. Herein, we report a synergistic strategy to exploit a unique nitrogen‐doped three‐dimensional graphene aerogel as both the lithium anode host to ensure homogeneous lithium plating/stripping and mitigate lithium dendrite formation and the sulfur cathode host to facilitate efficient sulfur redox chemistry and combat undesirable polysulfide shuttling effect, realizing Li–S battery simultaneously with ultrahigh energy density and long cycle life. The as‐demonstrated polysulfide‐based device delivers a high areal capacity of 7.5 mAh/cm² (corresponds to 787 Wh/L) and an ultralow capacity fading of 0.025% per cycle over 1000 cycles at a high current density of 8.6 mA/cm². Our findings suggest a novel strategy to scale up the superior electrochemical property of every microscopic unit to a macroscopic‐level performance that enables simultaneously high areal energy density and long cycling stability that are critical for practical Li–S batteries.