Synthesis of single-crystal LiNi0.8Co0.1Mn0.1O2 materials for Li-ion batteries by microfluidic technology

Single-crystal LiNixMnyCo1-x-yO2 (SC-NMC) cathode with electro-chemo-mechanically compliant microstructure is regarded as a promising candidate for high-energy-density lithium ion battery. However, the research of Ni-rich SC-NCM still lags behind its corresponding polycrystalline cathode materials, mainly due to the difficulties in synthesis. Herein, the single-crystal LiNi0.8Mn0.1Co0.1O2 cathode (SC-NCM811) was successfully synthesized by microfluidic technology combined with the solid-state lithiation process. The nano-sized Ni0.8C- o0.1Mn0.1(OH)2 precursor prepared via microfluidic technology enhances its accessibility to lithium salts, thus exhibiting high chemical activity for lithiation reaction. As a result, the optimized SC-NCM811 cathode shows relatively small-scale grain size (<3 mu m), low cation mixing and well layered structure, which is beneficial to electrochemical kinetics and redox reversibility. The electrochemical characterization results further reveal that the optimized SC-NCM811 cathode can well balance the cycle performance and rate capability, showing good electrochemical performance. Overall, microfluidic technology is expected to provide a new strategy for pre-paring single-crystal Ni-rich cathode materials, which may extend to the commercial application of other cathode materials.