First Graphene Ltd. and 2D Fluidics Pty Ltd. announce novel graphene-fullerene composites for energy storage applications. The unique Vortex Fluidics Device (“VFD”) developed by 2D Fluidics is able to produce graphene-wrapped-fullerene composites which have the potential to be used as an “all carbon” energy storage material. The technology is protected by international patent filings, currently progressing through national phase filings.
Currently, spherical graphite (SPG) is a crucial ingredient to the efficient operation of lithium-ion batteries (LiB). Spherical graphite is the key component of the anode of a LiB which without, the LiB would not function. Historically SPG has been derived from flake natural graphite.
The global production of spherical graphite is currently dominated by China, which uses the mechanical shaping and hydrofluoric acid purification techniques to produce purified spherical graphite. With the transition of the world to a clean, green energy platform many LiB manufacturers are actively seeking alternative supply options that offer better efficiencies. A number of companies around the world are researching alternatives graphite products to traditional spherical graphite as a basis for developing graphite mines, but graphene appears to offer something beyond graphite owing to its advanced properties.
FGR is in a unique position to produce a graphene-based spherical product by employing the VFD technology. Research to date has shown the graphene-fullerenes could be a suitable replacement for spheroid graphite used in anode manufacturing. The Company’s manufacturing process may have the potential to offer improvements in performance, which is a constant issue for battery manufacturers. The fullerenes have potential to enhance both Li-B and supercapacitors.
As with all of the other alternatives being worked on by a range of companies, the commerciality and scalability of the production process is dependent upon continuing research and development. Research and development work is being undertaken in FGR’s UK laboratory at the Graphene Engineering Innovation Centre, at the University of Manchester and with the University of Warwick.
Composite Fullerene C60 Graphite Spheres
Using both the original and the scaled up VFD units, 2D Fluidics has successfully replicated the production of composite C60 / graphene spheres. This work is reported in the publication “High Yield Continuous-Flow Synthesis of Spheroidal C60@graphene composites as supercapacitors”.[1] C60 refers to the fullerene form of carbon. It consists of a soccer-ball-shaped cluster of sixty carbon atoms. The graphene-wrapped fullerene composites have a “pom-pom” shape and are known for their unique energy levels and high value of electron affinity energy. They have shown high capacitance when tested in an electrochemical cell by Flinders University.
Importantly, the VFD can produce this material directly from FGR supplied graphite material (D90 500µm). The size of the spheres produced by the 20mm VFD were 1.5–3.0 µm. In the 50mm VFD, using the same raw material production volume was increased and the spheres were ≤ 1 µm.
The production of the “pom-pom” shaped graphene-wrapped fullerene spheres has been replicated at FGR’s UK laboratory, using similar operating conditions. The controlled manufacture of this new product could give the potential performance improvements when compared to the restricted sizing of conventional spherical graphite used as an anode material.
Further experiments in the 50 mm VFD at lower rotational speed will be conducted to demonstrate the ability to control the size of the spheres, test scalability of process and calculate production yield.
FGR are producing sufficient quantities of these novel materials for evaluation in energy storage applications at leading United Kingdom based universities, such as the University of Warwick. Of particular interest is the use of these materials as active materials in supercapacitors and also as Lithium-ion battery anodes.
[1] Raston et al, High-Yield Continuous-Flow Synthesis of Spheroidal C60@Graphene Composites as Supercapacitors, ACS Omega 2019, 4, 19279−19286