High Value-Added Regeneration of Anode Materials from Retired Lithium-Ion Batteries: Structural Design And Synthesis Process

Abstract

Recovery of anode materials from retired lithium-ion batteries attracted widespread attention because of the environmental and resource factors. Silicon carbon composites are expected to replace graphite due to the high specific capacity, stable voltage platform and abundant reserves of silicon. Herein, we have successfully synthesized spherical silicon/recovered-graphite composite (SSRC) with different silicon content (5%~20%) via a spray pyrolysis technology. For comparison, we fabricated 10% Si flaky silicon/recovered-graphite composite. The morphological and compositional analysis show Si nanoparticles can be uniformly distributed on the framework, thus the volumetric expansion of Si can be effectively relieved. The electrochemical properties indicate spherical material with 10% Si exhibits an outstanding cycling performance of 91.6% at 1.0 C over 200 cycles, surpassing that of flaky material (88.7%). Additionally, NMP and ethanol can be collected separately for reusing. Overall, this work proposed an efficient and environmentally friendly approach for recovering anode materials and enabling their value-added utilization.

Keywords: Retired lithium-ion batteries, anode materials, silicon/recovered-graphite composites, spray-pyrolysis technology, value-added utilization