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 (SGnPs) 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.

Atomic Layer‐by‐Layer Co3O4/Graphene Composite for High Performance Lithium‐Ion Batteries

“…Generally, ATMCNs-GE has much smaller electronic resistance ( R e ), electrolyte resistance ( R s ) and R ct values than ATMCNs at corresponding cycles, indicating smaller internal resistance, a more stable SEI fi lm ( Figure S7, Supporting Information) and improved reaction kinetics. [ 18 ] It is important to note that the atomic layer-by-layer ATMCNs-GE exhibits superior electrochemical performance compared with previously reported Co 3 O 4 /C (including graphene, carbon nanotubes, porous carbon, etc.) composites.…”

Graphene‐Nanowall‐Decorated Carbon Felt with Excellent Electrochemical Activity Toward VO2+/VO2+ Couple for All Vanadium Redox Flow Battery

“…The resistance of diffusion (Zw) during the reaction process can be determined from the slope of the straight line 41, 42, 43. An equivalent circuit diagram of these electrodes is also shown in Figure 5a.…”

Simultaneous Suppression of the Dendrite Formation and Shuttle Effect in a Lithium–Sulfur Battery by Bilateral Solid Electrolyte Interface

“…However, the severe shuttle effect and dendrite growth, and the inferior Coulombic efficiency that characterize these Li‐S batteries have greatly limited their lifespan 4, 8, 9, 10. Although much effort has been expended in the development of novel sulfur‐host electrodes,11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 separators,37, 38, 39, 40 and electrolytes41, 42, 43, 44, 45 to resolve these issues, some of which are rather dangerous, the results have been at best minimal in improving current Li‐S battery technology. As a result, the cycling life and Coulombic efficiency of Li‐S batteries, especially in the high‐rate regime, are still far behind the state of the art in lithium‐ion battery technology.…”