title: Sulfur-graphene nanostructured cathodes via ball-milling for high-performance lithium-sulfur batteries.
abstract: Although much progress has been made to develop high-performance lithium-sulfur batteries (LSBs), the reported physical or chemical routes to sulfur cathode materials are often multistep/complex and even involve environmentally hazardous reagents, and hence are infeasible for mass production. Here, we report a simple ball-milling technique to combine both the physical and chemical routes into a one-step process for low-cost, scalable, and eco-friendly production of graphene nanoplatelets (GnPs) edge-functionalized with sulfur (S-GnPs) as highly efficient LSB cathode materials of practical significance. LSBs based on the S-GnP cathode materials, produced by ball-milling 70 wt % sulfur and 30 wt % graphite, delivered a high initial reversible capacity of 1265.3 mAh g(-1) at 0.1 C in the voltage range of 1.5-3.0 V with an excellent rate capability, followed by a high reversible capacity of 966.1 mAh g(-1) at 2 C with a low capacity decay rate of 0.099% per cycle over 500 cycles, outperformed the current state-of-the-art cathode materials for LSBs. The observed excellent electrochemical performance can be attributed to a 3D "sandwich-like" structure of S-GnPs with an enhanced ionic conductivity and lithium insertion/extraction capacity during the discharge-charge process. Furthermore, a low-cost porous carbon paper pyrolyzed from common filter paper was inserted between the 0.7S-0.3GnP electrode and porous polypropylene film separator to reduce/eliminate the dissolution of physically adsorbed polysulfide into the electrolyte and subsequent cross-deposition on the anode, leading to further improved capacity and cycling stability.
authors.affiliation: Institute for Superconducting and Electronic Materials, University of Wollongong , Wollongong, NSW 2522, Australia.
authors.forename: Jiantie
authors.initials: J
authors.lastname: Xu
authors.forename: Jianglan
authors.initials: J
authors.lastname: Shui
authors.forename: Jianli
authors.initials: J
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Hua-Kun
authors.initials: HK
authors.lastname: Liu
authors.forename: Shi Xue
authors.initials: SX
authors.lastname: Dou
authors.forename: In-Yup
authors.initials: IY
authors.lastname: Jeon
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Seo
authors.forename: Jong-Beom
authors.initials: JB
authors.lastname: Baek
authors.forename: Liming
authors.initials: L
authors.lastname: Dai
keywords: ball milling; carbon paper; lithium sulfur batteries; sulfur-graphene nanoplatelets