Ceylon Graphite reports full cell performance of spherodized vein graphite anode materials for Li-ion batteries
Vancouver-based Ceylon Graphite (earlier post) has completed full cell testing using spherodized vein graphite materials in commercial size pouch cells following automotive standards. Ceylon Graphite’s vein graphite anode material exceeded comparable anodes made with industry-standard commercial synthetic graphite and was able to achieve excellent reproducibility in the tests carried out from 2021 through to 2023. This is the first time that spherodized vein graphite materials were tested in a lithium-ion battery full cell.
SEM image of spherodized material
The tests were conducted at Warwick Manufacturing Group (WMG), part of University of Warwick’s Energy Innovation Centre.
Repetitive testing of Ceylon Graphite’s unique natural vein graphite material demonstrated discharge capacity of 161 mAh/g, as compared to the published industry standard of 153 mAh/g; there was only a small loss in capacity over 120 cycles.
Ceylon Graphite suggests that the performance of the vein graphite material is due to the high crystallinity of vein graphite with the highest C% in nature (above 90%); in-house purification technology (pending patent) without using any HF (Hydro fluoric) acids; and Ceylon Graphite’s proprietary spherodizing and formulation technology.
The cells were tested in a full cell system at a rate of C/5, meaning 5 hours to charge and 5 hours to discharge. Extended cycling exhibited reversible charge/discharge behavior with less than 15% overall capacity loss over 120 cycles.
The C/5 stable cycling gives an average reversible capacity of 161 mAh/g for the best-performing vein graphite material, compared to 153 mAh/g for standard synthetic graphite measured at the same rate. The cell showed very good stability to cycling at various rates, including at very high current density. The battery could recover the capacity after cycling back at a low rate, indicating high-rate capability.