Graphene nanobuds (GNBs) are advanced carbon-based three-dimensional structures that have great prospects as anode materials for high-performance lithium-ion batteries due to their excellent electrolytic behavior.
Study: Graphene nanobuds as a novel anode design paradigm with superior Li-ion storage capacity and rate capability. Image Credit: peterschreiber.media/Shutterstock.com
A study published in the journal Carbon discussed using GNBs, formed on copper (Cu) foil via chemical vapor deposition, as an anode in lithium-ion batteries.
Main Challenge Faced by Lithium-Ion Batteries
Energy storage is a crucial aspect of the energy supply chain. It can boost energy grid stability and encourage the use of clean energy sources, lessening the reliance on fossil fuels and minimizing their environmental consequences.
Lithium-ion batteries are quickly becoming the most sought-after energy storage technology because of their large energy densities and extended cyclic ability.
Producing high-performance anode materials that possess excellent specific capacities and extended cyclic ability is currently one of the key development areas in lithium-ion batteries.
The energy storage capacity of lithium-ion batteries heavily depends on the anode materials used and their structure. Carbonaceous substances remain the anode materials of choice because of the strong attraction between lithium (Li) and graphitic carbon.
How Can Graphene Help?
Graphene is an extraordinary material that possesses a large capacity to accommodate lithium ions in its framework because of its significant surface area and excellent electrical conductivity.
Graphene is often synthesized by chemically exfoliating graphite or reducing graphite oxide; such methods are very cost-effective and practical.
Utilizing Reduced Graphene Oxide for Lithium-Ion Batteries
Reduced graphene oxide (rGO) has relatively high capacity levels. When used as an anode, rGO exhibits a large irreversible capacity. This ultimately means that the accumulated Li never entirely recovers following Li injection, leading to poor coulombic efficiency in the initial cycle.
Therefore, using graphene oxide in lithium-ion batteries has proved to be challenging thus far.
Pairing Graphene with Fullerene to Create Graphene Nanobuds
Additional carbon-based nanomaterials may be introduced to graphene to boost its energy storage capacity and cyclic stability and improve its anode suitability in lithium-ion batteries.
Energy storage capacity may be enhanced by the covalent bonding of fullerenes on the surface of graphene. Therefore, incorporating fullerenes with graphene is an effective technique for developing a novel nanostructure with strong electrocatalytic capabilities.
Unique three-dimensional structures called graphene nanobuds are formed by coupling these carbon-based materials. While this composite material has demonstrated remarkable electrolytic characteristics, its full potential in lithium-ion battery applications is yet to be explored.
What Did the Researchers Do?
This study describes the production of a graphene nanobud composite, which exhibited remarkable electrolytic energy storage capabilities.
A customized CVD process was used to fabricate the graphene nanobuds in a singular step. The team used Cu foil for the current collection at the anode of a lithium-ion battery. So, the study focused on fabricating graphene nanobuds deposited on a copper platform.
A customized chemical vapor deposition technique was used to create few-layer and multilayer GNBs. These graphene nanobuds showed excellent electrolytic characteristics, highlighting their potential as anode materials in lithium-ion batteries.
The few-layer GNBs outperformed the multilayer GNBs in terms of electrochemical performance, exhibiting a better energy storage capacity, a higher current rate, and outstanding cycle stability, all while maintaining a faradaic efficiency of 99 %.
The developed graphene nanobuds had the inherent qualities of improving lithium-ion storage and diffusion. These inherent qualities are responsible for the improved capacity, better reversibility, and outstanding cycle performance exhibited by the graphene nanobuds.
Directly growing the active material on the copper current collector enabled the electrode to retain excellent electrical conduction and superior rate capability, leading to highly improved electrolytic qualities for high-performance lithium-ion batteries.
These findings can pave the way for future work on the design of high-performance carbonaceous anode materials for cutting-edge lithium-ion batteries.
González, I. Z., Chiu, H.-C., Gauvin, R., et al. (2022). Graphene nanobuds as a novel anode design paradigm with superior Li-ion storage capacity and rate capability. Carbon. Available at: https://doi.org/10.1016/j.carbon.2022.07.010