Coprecipitation–driven memory effect. Linking precursor precipitation conditions to NMC811 cathode performance

The growing demand for high-performance lithium-ion batteries, especially in electric vehicles, has increased the focus on optimizing the production of nickel-rich cathode materials such as NMC811. This study investigates the synthesis of LiNi0.8Mn0.1Co0.1O2 (NMC811) via coprecipitation as oxalates, focusing on the effect of metal concentration (0.2 M, 1 M, 2 M) and reaction time (6 h, 24 h). The materials were characterized using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Inductively Coupled Plasma spectroscopy, and Particle Size Analysis. Electrochemical tests, including cycling stability and rate capability, assessed the impact of synthesis conditions on performance.Results show that both metal concentration and coprecipitation reaction time significantly influence particle morphology, size distribution, crystallinity, and electrochemical behavior. The final cathode material is strongly affected by these parameters, showing a marked memory of the precursor's properties. Materials synthesized at 2 M for 24 h exhibited the highest specific capacity and excellent capacity retention across a wide range of C-rates. In contrast, lower concentrations or shorter times yielded inferior performance, with reduced capacity and greater fading. This study demonstrates that careful control of synthesis conditions enables the development of nickel-rich NMC811 with high electrochemical performance, offering valuable insights for improving lithium-ion battery manufacturing.