A research group led by Hiroyuki Isobe, Senior Researcher of the Advanced Research Organization for Atomic and Molecular Materials, Tohoku University, has developed a new negative electrode material for all-solid-state lithium-ion batteries. A material called "perforated graphene molecule (CNAP)", a macrocyclic organic molecule with a nanometer-sized (nano is one billionth) hole in the center of the molecule.It has more than twice the electric capacity of existing negative electrode materials using graphite.It is the first time in the world that macrocyclic organic molecules have been shown to be suitable as electrode materials for lithium-ion batteries.
CNAP is made from the common molecule "naphthalene" used in insect repellents, and it was discovered that simply by connecting these molecules in a ring shape, it becomes a large-capacity negative electrode material. The large capacity is completely maintained even after repeated charging and discharging 65 times.The research group has experimentally found that the finely crafted pores in the molecular material are the key to CNAP's large capacitance.
Negative electrode materials for lithium-ion batteries have long been the dominant source of graphite.Recently, it has been shown that the electric capacity of negative electrode carbon materials using graphene and carbon nanotubes can be more than doubled, and it is attracting attention.However, since various structures are mixed in these carbon materials, it is difficult to elucidate the mechanism of increasing the capacity, which hinders the realization of further increasing the capacity.