Recycling with precision: engineering Ni-rich NMC cathodes through impurity management

Abstract

The exponential rise in lithium-ion battery (LIB) demand is placing unprecedented pressure on critical metal resources (e.g., Li, Ni, Co), while also generating large volumes of end-of-life battery waste. Although recycling offers a sustainable alternative to virgin mineral extraction, residual impurities introduced during recycling often degrade the performance of resynthesised cathode active materials. In this study, we investigate the structure, morphology and electrochemical properties of LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathodes resynthesised from metal salts recovered from spent LIB black mass through an industrial-scale recycling process. The resynthesised cathodes achieved battery-grade purity (99.6%) and exhibited comparable composition and crystal structure to the commercial reference, although morphological deviations were observed due to impurity-induced effects during resynthesis. They delivered an initial discharge capacity of 175.1 mAh g⁻¹ with a coulombic efficiency of 92.6% at 0.05C during the first formation cycle, tested in NMC‖graphite full cells with an areal loading of 11.3 mg cm⁻². At 0.2C, the discharge capacity reached 165.3 mAh g⁻¹, with 95.1% capacity retention after 50 cycles. This study demonstrates the practical feasibility of incorporating recovered precursors into NMC811 cathode production, advancing circularity in LIB manufacturing, while also highlighting that impurity sensitivity during resynthesis remains an important consideration.