Abstract

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 CuF2 core and SA layer that inhibiting the dissolution of CuF2, the synthesized CuF2@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.