Universal high-performance bulk graphites from natural flake graphite by rapid sintering

High performance graphites (HPGs) are a key material in modem industries; however, prevailing HPGs are short of comprehensive properties in many aspects, i.e., a specific property of HPGs is always achieved at the cost of other properties. And the production of HPGs is highly costly and causes severe environmental problems. Current HPGs are derived from various carbonaceous precursors, excluding nature flake graphite (NFG), the best graphite source. Typically, NFG-based bulk graphite has poor mechanical properties because NFG is difficult to sinter. Here we report the preparation and comprehensive properties of a new family of universal HPGs (U-HPGs) that can be mass-produced with moderate conditions by sintering NFG slightly mixed with diamond, where units of onion carbon (OC) with NFG (OC@NFG) act as building blocks. OC@NFG creates a strong interfacial network between the NFGs, giving the U-HPGs outstanding strength and moderate hardness. With U-HPGs being more than 93 % graphitization, the flexural strength exceeds 100 MPa, far superior to mainstream commercial graphites. OC@NFG also bestows U-HPGs with excellent thermal conductivity(>125 W m−1 K−1 at room temperature). For such structure provides a 3D path for electrons inside U-HPGs, the as-produced material has significant electronical conductivity. This work presents new insights into this old yet important material and allows for innovative design of HPGs for various applications.