Low-Platinum Medium-Entropy Intermetallic Compounds Based on the Synergistic Utilization of Spent Lithium-Ion...

The resource utilization of high-value transition metals from traditional waste ternary lithium-ion batteries holds significant appeal in the field of lithium-oxygen batteries, yet the diversification of utilization routes and the development of innovative strategies remain highly challenging. In this work, we propose for the first time a synergistic recycling strategy: recycling carbon (RC) from spent lithium-ion battery anodes as a matrix, synergistically utilizing it with recovered transition metals from cathodes to prepare a low-platinum, medium-entropy intermetallic compound Pt(NiCoMn)₃ as a cathode catalyst. Both experimental and theoretical results demonstrate that the Joule heating alloying of recycled NiCoMn with Pt not only creates an ordered, medium-entropy coordination environment within the low-Pt intermetallic compound, inducing lattice distortion, but also triggers electron transfer from Ni/Co/Mn to highly electronegative Pt. This lattice distortion and local electron redistribution reposition the center of the Pt d-band, while Ni/Co/Mn orbital hybridization with Pt optimizes the electronic structure of the catalytic center, promoting the deposition and decomposition kinetics of thin-film Li₂O₂ discharge products. Electrochemical testing shows that the Pt(NiCoMn)₃@RC catalyst exhibits a low overpotential of 0.35 V and achieves a cycle life of 319 cycles at 400 mA g^-1 and 1000 mAh g^-1.