Submillimeter single-crystal monolayer and multilayer graphene domains were prepared by an atmospheric pressure chemical vapor deposition method with suppressing nucleation on copper foils through an annealing procedure. A facile oxidation visualization method was applied to study the nucleation density and morphology of graphene domains on copper foils. Scanning electron microscopy, transmission electron microscopy, atomic force microscopy, polarized optical microscopy, and Raman spectra showed that the submillimeter graphene domains were monolayer single crystals.

In this work, a multifunctional binder with self‐healing, flame retardant, high conductivity, and abundant polar groups is prepared by the free radical polymerization method and applied to lithium–sulfur (Li‐S) batteries to achieve high safety and exceptional electrochemical performance. The self‐healing characteristic of binder induced by intermolecular hydrogen bonds and SS dynamic covalent bonds can repair volume expansion cracks. The polar groups and excellent conductivity endue binder with strong chemisorption on polysulfides and fast charge transportation, which can effectively inhibit the shuttle effect and accelerate polysulfides redox kinetics. More important, the considerable flame retardant performance of binder can improve the safety of the LiS batteries. As a result, the LiS cells using FHCP binder deliver an outstanding cycle stability of a high‐capacity retention rate of 85% after 100 cycles at 0.2 C, and a high reversible area specific capacity of 5.25 mAh cm–2 at a sulfur loading of 4.72 mg cm–2 and a correspondingly lean electrolyte condition (E/S ratio = 6 µL mg–1).

We present a new type of in situ reduction-assembly approach to construct graphene hydrogel through simultaneous water evaporation and graphene oxide reduction.