Transition Metal Oxides and Li₂CO₃ as Precursors for the Synthesis of Ni-Rich Single-Crystalline NCM for Sustainable Lithium-Ion Battery Production

Single-crystalline Ni-rich LiNi_1-x-y Co _x Mn _y O₂ (SC-NCM) cathode active materials promise to increase the lifetime of high energy Li-ion batteries. SC-NCM consist of large primary particles that offer low surface area, limiting detrimental chemical reactions while exhibiting high morphological stability. A typical SC-NCM synthesis starts from the same Ni_1-x-y Co _x Mn _y (OH)₂ and LiOH∙H₂O precursors commonly used for conventional spherical poly-crystalline NCM (PC-NCM), but requires higher temperatures and additional post-processing. Consequently, the cost and environmental impact of the production of Ni-rich SC-NCM is higher compared to the production of PC-NCM. In this study, we demonstrate a synthesis of SC-NCM that does not require the same highly engineered precursors as used for PC-NCM. We propose a more energy-efficient and cost-effective route that involves simple blending of NiO, MnO, Co₃O₄ and Li₂CO₃ which yields single-crystalline LiNi_0.83Co_0.11Mn_0.06O₂ with 2–3 μm particle size and good structural quality. It is shown by in situ XRD during synthesis that—while the reaction suffers from slow kinetics—the elevated temperature and longer reaction time, which are in any case required for the crystal growth, are sufficient to also complete the reaction. Furthermore, it is shown that this material is structurally and electrochemically equivalent to the material commonly synthesized from hydroxide-based precursors.