US 2019/0067732 Al  11  Feb.28,2019  [0112]  Exfoliated graphite worms may be subjected to  high-intensity mechanical shearing/separation treatments  using a high-intensity air jet mill, high-intensity ball mill, or  ultrasonic device to produce separated nano graphene plate› lets (NGPs) with all the graphene platelets thinner than 100  nm, mostly thinner than 10 nm, and, in many cases, being  single-layer graphene (also illustrated as  112  in FIG.  2(8)).  An NGP is composed of a graphene sheet or a plurality of  [0109]  The aforementioned features are further described  and explained in detail as follows: As illustrated in FIG.  2(8),  a graphite particle (e.g.  100)  is typically composed of  [0108]  The nitrogenation of graphene can be conducted by  exposing a graphene material, such as graphene oxide, to  ammonia at high temperatures (200-400°  C.). Nitrogenated  graphene could also be formed at lower temperatures by a  hydrothermal method; e.g. by sealing GO and ammonia in  an autoclave and then increased the temperature to 150-250°  C. Other methods to synthesize nitrogen doped graphene  include nitrogen plasma treatment on graphene, arc-dis› charge between graphite electrodes in the presence of  ammonia, ammonolysis of graphene oxide under CVD  conditions, and hydrothermal treatment of graphene oxide  and urea at different temperatures.  [0111]  Acids, such as sulfuric acid, are not the only type of  intercalating agent (intercalant) that penetrate into spaces  between graphene planes to obtain GICs. Many other types  of intercalating agents, such as alkali metals (Li, K, Na, Cs,  and their alloys or eutectics ), can be used to intercalate  graphite to stage 1, stage 2, stage 3, etc. Stage n implies one  intercalant layer for every n graphene planes. For instance,  a stage-I potassium-intercalated GIC means there is one  layer of K for every graphene plane; or, one can find one  layer of K atoms inserted between two adjacent graphene  planes in a G/K/G/K/G/KG . . . sequence, where G is a  graphene plane and K is a potassium atom plane. A stage-2  GIC will have a sequence ofGG/K/GG/K/GG/K/GG ... and  a stage-3 GIC will have a sequence of GGG/K/GGG/K/  GGG ... etc. These GICs can then be brought in contact  with water or water-alcohol mixture to produce exfoliated  graphite and/or separated/isolated graphene sheets.  [0107]  For exfoliating a layered precursor material to the  state of individual layers or few-layers, it is necessary to  overcome the attractive forces between adjacent layers and  to further stabilize the layers. This may be achieved by either  covalent modification of the graphene surface by functional  groups or by non-covalent modification using specific sol› vents, surfactants, polymers, or donor-acceptor aromatic  molecules. The process of liquid phase exfoliation includes  ultra-sonic treatment of a graphite fluoride in a liquid  medium.  [0110]  Due to the weak van der Waals forces holding the  parallel graphene layers, natural graphite can be treated so  that the spacing between the graphene layers can be appre› ciably opened up so as to provide a marked expansion in the  c-axis direction, and thus form an expanded graphite struc› ture in which the laminar character of the carbon layers is  substantially retained. The process for manufacturing flex› ible graphite is well-known in the art. In general, flakes of  natural graphite  (e.g.100  in FIG.  2(8))  are intercalated in an  acid solution to produce graphite intercalation compounds  (GICs,  102).  The GICs are washed, dried, and then exfoli› ated by exposure to a high temperature for a short period of  time. This causes the flakes to expand or exfoliate in the  c-axis direction of the graphite up to 80-300 times of their  original dimensions. The exfoliated graphite flakes are ver› miform in appearance and, hence, are commonly referred to  as graphite worms  104.  These worms of graphite flakes  which have been greatly expanded can be formed without  the use of a binder into cohesive or integrated sheets of  expanded graphite, e.g. webs, papers, strips, tapes, foils,  mats or the like (typically referred to as "flexible graphite"  106)  having a typical density of about 0.04-2.0 g/cm 3  for  most applications.  [0106]  Interaction ofF$_{2 }$ with graphite at high temperature  leads to covalent graphite fluorides  (CF)n  or (C$_{2}$F)n, while at  low temperatures graphite intercalation compounds (GIC)  CxF  (2sxs24) form. In  (CF)n  carbon atoms are sp3-hybrid› ized and thus the fluorocarbon layers are corrugated con› sisting of trans-linked cyclohexane chairs. In  (C$_{2}$F)n  only  half of the C atoms are fluorinated and every pair of the  adjacent carbon sheets are linked together by covalent C----C  bonds. Systematic studies on the fluorination reaction  showed that the resulting F/C ratio is largely dependent on  the fluorination temperature, the partial pressure of the  fluorine in the fluorinating gas, and physical characteristics  of the graphite precursor, including the degree of graphiti› zation, particle size, and specific surface area. In addition to  fluorine (F $_{2}$ ),  other fluorinating agents may be used,  although most of the available literature involves fluorina› tion with F  2  gas, sometimes in presence of fluorides.  [0105]  Fluorinated graphene or graphene fluoride is herein  used as an example of the halogenated graphene material  group. There are two different approaches that have been  followed to produce fluorinated graphene: (1) fluorination of  pre-synthesized graphene: This approach entails treating  graphene prepared by mechanical exfoliation or by CVD  growth with fluorinating agent such as XeF  2 ,  or F-based  plasmas; (2) Exfoliation of multilayered graphite fluorides:  Both mechanical exfoliation and liquid phase exfoliation of  graphite fluoride can be readily accomplished.  multiple graphite crystallites or grains. A graphite crystallite  is made up of layer planes of hexagonal networks of carbon  atoms. These layer planes of hexagonally arranged carbon  atoms are substantially flat and are oriented or ordered so as  to be substantially parallel and equidistant to one another in  a particular crystallite. These layers of hexagonal-structured  carbon atoms, commonly referred to as graphene layers or  basal planes, are weakly bonded together in their thickness  direction ( crystallographic c-axis direction) by weak van der  Waals forces and groups of these graphene layers are  arranged in crystallites. The graphite crystallite structure is  usually characterized in terms of two axes or directions: the  c-axis direction and the a-axis ( or b-axis) direction. The  c-axis is the direction perpendicular to the basal planes. The  a- or b-axes are the directions parallel to the basal planes  (perpendicular to the c-axis direction).  material ( e.g. natural graphite powder) in an oxidizing liquid  medium ( e.g. a mixture of sulfuric acid, nitric acid, and  potassium permanganate) in a reaction vessel at a desired  temperature for a period of time (typically from 0.5 to 96  hours, depending upon the nature of the starting material and  the type of oxidizing agent used). As previously described  above, the resulting graphite oxide particles may then be  subjected to thermal exfoliation or ultrasonic wave-induced  exfoliation to produce isolated GO sheets. These GO sheets  can then be converted into various graphene materials by  substituting -OH groups with other chemical groups (e.g.  -Br, NH$_{2}$ ,  etc.). 