Ball-Milling Synthesis of Richly Oxygenated Graphene-Like Nanoplatelets from used Lithium Ion Batteries and Its Application for High Performance Sodium Ion Battery Anode

The exploration of waste graphite from used lithium ion batteries (LIBs) and its derivatives for versatile applications is an efficient route to promote the environmental and eco-friendly recycling of used LIBs. Sodium ion batteries (SIBs) are alternative candidates to LIBs mainly due to similar electrochemical mechanism of SIBs to LIBs and rich natural resource of Na. Herein, a holey waste graphite (hGw) with well-defined porous structure is produced by the annealing of lithiated waste graphite (Li/Gw) from used LIBs under a flow gas of H2O and subsequent lithium leaching in DI water. Benefiting from the holey structure of hGw, holey graphene nanoplatelets (hGnw) with ultrahigh-level edge-grafted oxygen groups (approximate to 37.8 at%) are synthesized by mechanical balling of hGw. As anode for SIBs, the hGnw present outstanding sodium ion storage properties with high initial Coulombic efficiency of 82.4%, high reversible capacity (e.g., 416.1 mAh g-1 at 0.03 A g-1), excellent rate capability (e.g., 153.3 mAh g-1 at 2 A g-1), and long-term cycling stability (e.g., 152.7 mAh g-1 after 400 cycles at 1.5 A g-1). Benefitting from the rich oxygenated groups at edges as additional active sites, as well as large accessible surface area and enlarged interlayer distance between graphitic layers at edges, the graphene nanoplatelets prepared from waste graphite displays outstanding sodium ion storage properties. image