Synthesis of Expanded Holey Graphene as Anode and Na2FePO4F as Cathode for High Performance Sodium Ion Batteries Based on the Recycled Electrodes from Spent Lithium Ion Batteries

Owing to the increasing demand on the valuable metals and growing awareness on the environmental protection, efficient recycling of spent lithium ion batteries (LIBs) has attracted great concerns recently. Apart from their reuse for LIBs, the recycled electrode materials from spent LIBs for other applications is also an important research direction. Sodium ion batteries (SIBs) are ideal alternatives to LIBs due to the more abundant natural sources of Na than Li and their similar electrochemical mechanism. Herein, we develop a simple and efficient approach for the synthesis of expanded reduced holey spent graphene oxide (c-rhSG) and carbon coated Na 2 FePO 4 F (NFPF) based on the lithiated graphite (Li x C 6 ) anode and delithiated Li 1- x FePO 4 cathode from spent LIBs as starting materials, respectively. For half-cell applications, both c-rhSG and carbon coated NFPF electrodes display outstanding sodium storage properties. With the use of c-rhSG as anode and carbon coated NFPF as cathode, the full-cell SIB demonstrates a high reversible capacity of 116.3 mAh g –1 at 0.1 C, excellent rate capability ( e.g. , 57.7 mAh g –1 at 5 C) and long cycling stability over 500 cycles. • A facile recovery of the discharged Li 1- x FePO 4 cathode and charged graphite anode. • An efficient the synthesis of the carbon coated NFPF and c-rhSG. • The recovery electrode materials both show outstanding sodium storage properties.