Researchers at Changsha University of Science & Technology in China have used spent asphalt to produce a high-performance universal Li/Na/K-ion anode material. A paper on their work is published in the Journal of Power Sources.
Asphalt is a dark brown to black cementitious material in which the predominating constituents are bitumens which occur in nature or are obtained in petroleum processing. Asphalt is a constituent in varying proportions of most crude petroleums and is widely used as a binder for paving aggregates such as sand, gravel, slag or crushed stone.
Asphalt is also used for roofs, coatings, floor tilings, soundproofing, waterproofing, and other building-construction elements and in a number of industrial products, such as batteries. Spent asphalt is widely available, and even poses environmental risks.
In an effort to produce lower-cost and widely available battery materials, the Changsha team converted spent asphalt into mesoporous carbon with an interconnected three-dimensional porous structure, high surface area, and numerous rich crystal defects.
Xie et al.
As an anode material for Li-ion batteries, the mesoporous carbon exhibits a reversible capability of 674.2 mAh g−1 at 0.2 A g−1 as well as excellent rate and cycling performance (258.7 mAh g−1 at 1.0 A g−1 after 1000 cycles) owing to the shortened diffusion path of ions and easier penetration of electrolytes.
The carbon anode also delivers superior reversible capacities and cycling stability in Na-ion and K-ion batteries.
With the potential to simultaneously tackle energy and environmental problems, the spent asphalt-derived mesoporous carbon is promising for large-scale applications.
Mingming Xie, Xiaobo Zhu, Danqing Li, Zhizhao Xu, Yingjia Huang, Huanyi Zha, Mei Ding, Chuankun Jia (2021) “Spent asphalt-derived mesoporous carbon for high-performance Li/Na/K-ion storage,” Journal of Power Sources, Volume 514, doi: 10.1016/j.jpowsour.2021.230593.