From graphite of used lithium-ion batteries to holey graphite coated by carbon with enhanced lithium storage capability.

ABSTRACT

The efficient recycling of waste graphite anode from used lithium-ion batteries (LIBs) has attracted considerable concerns mainly owing to the environment protection and reutilization of resources. Herein, we reported a rational and facile strategy for the synthesis of holey graphite coated by carbon (hG0.01@C0.10) through the separation, purification and creation of holey structures of waste graphite by using NaOH and carbon-coating by using phenolic resin. The holey structures facilitate the hG0.01@C0.10 with the quick penetration of electrolytes and rapid diffusion of Li+. The carbon coating is more favorable for hG0.01@C0.10 with improved electronic conductivity and less alleviated volume during the cycles. Benefiting from the synergistic effect of holey structures and carbon coating, the hG0.01@C0.10 as anode for LIBs displays a high reversible capacity of 377.6 mAh g-1 at 0.5 C and superior rate capabilities (e.g., 348.0 and 274.7 mAh g-1 at 1 and 2 C, respectively) and maintains a high reversible capacity of 278.7 mAh g-1 at 1 C after 300 cycles with an initial capacity retention of 80.0 %.