Design of Size‐Controlled Sulfur Nanoparticle Cathodes for Lithium‐Sulfur Aviation Batteries

Abstract Lithium–sulfur (Li–S) battery has been considered as a strong contender for commercial aerospace battery, but the commercialization requires Ah‐level pouch cells with both efficient discharge at high rates and ultra‐high energy density. In this paper, the application of lithium–sulfur batteries for powering drones by using the cathode of highly dispersed sulfur nanoparticles with well‐controlled particle sizes have been realized. The sulfur nanoparticles are prepared by a precipitation method in an eco‐friendly and efficient way, and loaded on graphene oxide‐cetyltrimethylammonium bromide by molecular grafting to realize a large‐scale fabrication of sulfur‐based cathodes with superior electrochemical performance. A button cell based on the cathode exhibits an excellent discharge capacity of 62.8 mAh cm −2 at a high sulfur loading of 60 mg cm −2 (i.e., 1046.7 mAh g −1 ). The assembled miniature pouch cell (PCmini) shows a discharge capacity of 130 mAh g −1 , while the formed Ah‐level pouch cell (PCAh) achieves energy density of 307 Wh kg −1 at 0.3C and 92 Wh kg −1 at 4C. Especially, a four‐axis propeller drone powered by the PC has successfully completed a long flight (>3 min) at high altitudes, demonstrating the practical applicability as aviation batteries.