Spent Graphite from End-of-Life Lithium-Ion Batteries (LIBs) as a Promising Nanoadditive to Boost Road Pavement Performance

Abstract

To take swift action towards tackling the global pollution crisis of discarded lithium-ion batteries (LIBs) while reinforcing road structures, this investigation was undertaken. The influence of various proportions of spent graphite (e.g., 5, 10, and 15 wt.% SG), harvested from end-of-life LIBs, on the performance of base AP-5 asphalt cement was studied. Multiple laboratory techniques have been employed to characterize the internal physiochemical interaction between the additive and the binder. These techniques include: elemental analysis (EA), thin-layer chromatography-flame ionization detection (TLC-FID), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), empirical test methods (e.g., penetration, softening point, viscosity, and ductility), dynamic shear rheometer (DSR), and multiple stress-creep recovery (MSCR). Prior to aging, SARA analysis demonstrated that the incremental SG addition into the AP-5 bitumen reduced the contents of saturates, aromatics, and resins, and increased the proportion of asphaltenes. After aging, the saturated and aromatic hydrocarbons kept decreasing; however, the resins increased and the asphaltenes declined. Accordingly, this has brought a progressive shift tendency in the stable–colloidal system for all binders from sol-state towards sol-gel-state. FT-IR scan revealed that the SG has no apparent chemical interaction with the binder, and is endowed solely with filling effects. XRD diagnosis highlighted that the steady SG incorporation into the binder amplified its crystallinity; thereby boosting the thermomechanical properties of mastics. SEM imaging unveiled that the lower-dose of SG exhibited higher compatibility within the bitumen matrix; nevertheless, the intermediate/higher-doses made the binder body relatively rougher. DSR/MSCR/conventional tests indicated that when the asphalt is blended with the graphitic powder under unaged/aged conditions, it becomes stiffer, more viscous, and less cohesive; thereby rendering it more resistant to deformation but not to cracking. In summary, it is promisingly proven that the SG could be successfully used as an asphalt additive and could be beneficial for improving paving performance and mitigating the pollution caused by dead LIBs as well.

Uncovering the Hidden Value of Waste Cow Bones Towards their Use as a Sustainable Biofiller for Hot-Mix Asphalt Paving Applications

“…The saturates were obtained by using an n-hexane solution (70 mL, 45 min). The aromatics were eluted by using a toluene solution (70 mL, 17 min); meanwhile, the resins were gotten by using a mixture of sample solution methanol/dichloromethane (3.50/66.50 mL, 5 min) [14]. The asphaltenes remain intact at the spotting zone.…”

“…When the separation is done, the chromarods' rack was placed in the Iatroscan instrument to allow for scanning at 30 s scan -1 , while employing an air/hydrogen flame fueled by an air flow rate of 2000 mL min -1 and a hydrogen flow rate of 160 mL min -1 . To insure both reproducibility and repeatability, the TLC-FID was conducted 4 times (i.e., each asphaltic sample/10 chromarods) [14].…”

“…In fact, to be considered for usage, it is of utmost importance that a sufficient quantity with an unceasing supply of a given material should be available on demand. In an attempt to save materials and energy while boosting road pavement performance, numerous recycling projects have been successfully executed by the Departments of Chemical Engineering and Architectural Engineering in KOREATECH [9][10][11][12][13][14][15]. From the concept of saving energy and conserving natural resources, creative approaches and strategies should be initiated and developed accordingly.…”

Study on Aging Mechanism and High-Temperature Rheological Properties of Low-Grade Hard Asphalt

“…The dynamic shear rheological (DSR) test is utilized to investigate the high-temperature rheological properties of asphalt, while the rutting factor (G*/sinδ) serves as an indicator for evaluating its high-temperature performance [ 15 , 16 ]. Moreover, some scholars propose the multi-stress creep recovery (MSCR) test to effectively assess the rheological properties of asphalt, with its high-temperature performance evaluated through parameters such as creep recovery rate and non-recoverable creep compliance [ 17 , 18 ].…”