Boosting the high-temperature graphitization of non-graphitizable carbons by ball-milling

Abstract

The high crystallinity structure endows carbon materials with exceptional electrical and thermal conductivity, making them suitable for high-end industrial applications, such as graphite for lithium-ion battery. However, the non-graphitizable carbons are hardly converted to graphite even at 3000 °C due to their highly disordered nanotexture. Herein, we propose that re-structuring non-graphitizable carbons through ball-milling can significantly boost their crystallinity after 2800 °C treatment using a activated carbon as a research model. Ball milling-induced order rearrangement of carbon layers promotes the development of the large graphenic crystallites toward graphite structure during the subsequent heat treatment. As a utilization exemplification for lithium storage, the optimal sample shows a greatly improved plateau capacity (<0.2 V, 194.8 vs. 155.1 mAh g−1) compared to the one obtained without ball-milling pre-modulation. Furthermore, the same approach was also applied to three typical non-graphitizable carbons derived from polymers and biomass, showing a similar result. This indicates that ball-milling may be a universal pre-treatment strategy for boosting the high-temperature “graphitization” of non-graphitizable carbon materials for advanced applications.