High‐Performance Pomegranate‐Like CuF2 Cathode Derived from Spent Lithium‐Ion Batteries

With the large‐scale application of lithium‐ion batteries (LIBs), a huge amount of spent LIBs will be generated each year and how to realize their recycling and reuse in a clean and effective way poses a challenge to the society. In this work, using the electrolyte of spent LIBs as solvent, we in situ fluorinate the conductive three‐dimensional porous copper foam by a facile solvent‐thermal method and then coating it with a cross‐linked sodium alginate (SA) layer. Benefiting from the solid‐electrolyte interphase (SEI) that accommodating the volume change of internal CuF 2 core and SA layer that inhibiting the dissolution of CuF 2 , the synthesized CuF 2 @void@SEI@SA cathode with a pomegranate‐like structure (yolk‐shell) exhibits a large reversible capacity of ~535 mAh g −1 at 0.05 A g −1 and superb cycling stability. This work conforms to the development concept of green environmental protection and comprehensively realizes the unity of environmental, social and economic benefits.