A team from Hainan University led by Professor Li Jianlin recently achieved a breakthrough in high-performance graphite ceramics research and the paper Nanoburl Graphites was published in the March 2021 issue of Advanced Materials, a top international journal in the field of materials science.

Inspired by the burl strengthening mechanism observed in tree trunks, the team, led by Li from the College of Materials Science and Engineering of HNU, designed and made the nanoburl graphites.

Covalent bonds are built between carbon atoms by sp3 hybridization at the interface between the graphite onions and flakes. Thus, pairs of pseudo‐Schottky junctions are created by the hybridization, which further enhances the bonding between the graphite onions and flakes.

With these bonding mechanisms, and with voids between the graphite powders filled in by the volume expansion associated with the change of nano-diamonds to the graphite onions, the loose compaction of graphite powder becomes consolidated at 1,700 C. The proposed nanoburl mechanism bestows the nanoburl graphites with strength five times that of conventional graphites prepared from graphite powders. The concept of nanoburl strengthening is instructive in the microstructural design and property enhancement of other layered materials.

Professor Li has long been engaged in the basic theory, manufacturing technology, and application research of ceramic materials. Lin Kunpeng, a postgraduate student in the team, was the first author of the paper. The relevant research groups of Donghua University, the Institute of Physics of the Chinese Academy of Sciences, and Zhejiang University all contributed to the paper.

Illustration of Li Jianlin's thesis Nanoburl Graphites, which was published in the March 2021 issue of Advanced Materials.