Upcycling the Spheroidization Tailings of Graphite into High-Performance Anodes for Lithium and Sodium-Ion Batteries

Abstract To develop cost-effective and scalable manufacture approaches for anode materials has long been one of the crucial research topics in the fields of lithium and sodium ion batteries. Herein, the graphite spheroidization tailings, a low-value by-product from graphite anode manufacturing, are upcycled into high performance anode materials for both lithium and sodium ion batteries through a spray-drying granulation followed by pitch coating and carbonization. Benefiting from the special structural configuration, the secondary particles prepared from the graphite spheroidization tailings as anode in lithium ion battery can deliver a reversible specific capacity of 348.6 mAh g–1 with an initial Coulombic efficiency (ICE) of 86%, and the specific capacity retains at 328.6 mAh g–1 after 400 cycles at 1 C. In sodium-ion batteries, the secondary particles show a reversible specific capacity of 112.6 mAh g–1 and an ICE of 83%, and it can be maintained at 97.8 and 91.1 mAh g–1 even at ultrahigh rates of 30 C and 50 C, respectively. After 2000 cycles at 10 C the specific capacity for sodium ion storage can still reach to 102.5 mAh g–1. The electrochemical kinetic analyses reveal that lithium storage is mainly governed by diffusion-controlled ion intercalation, whereas sodium storage proceeds through an ultrafast co-intercalation of solvated Na+.