A process for combination of recycling lithium and regenerating graphite from spent lithium-ion battery.

Recycling lithium and graphite from spent lithium-ion battery plays a significant role in mitigation of lithium resources shortage, comprehensive utilization of spent anode graphite and environmental protection. In this study, spent graphite was firstly collected by a two-stage calcination. Secondly, under the optimal conditions of 1.5 M HCI, 60 min and solid-liquid ratio (S/L) of 100 g·L, the collected graphite suffers simple acid leaching to make almost 100% lithium, copper and aluminum in it into leach liquor. Thirdly, 99.9% aluminum and 99.9% copper were removed from leach liquor by adjusting pH first to 7 and then to 9, and thenthe lithium was recovered by adding sodium carbonate in leach liquor to form lithium carbonate with high purity (>99%). The regenerated graphite is found to have high initial specific capacity at the rate of 37.2 mA·g (591 mAh·g), 74.4 mA·g (510 mAh·g) and 186 mA·g (335 mAh·g), and with the high retention ratio of 97.9% after 100 cycles, it also displays excellent cycle performance at high rate of 372 mA·g. By this process, copper and lithium can be recovered and graphite can be regenerated, serving as a sustainable approach for the comprehensive utilization of anode material from spent lithium-ion battery.