Continuous room temperature co-precipitation scale-up toward Zr-doped NMC811 cathode materials

A new continuous, room temperature synthesis process incorporating an in-line dynamic mixer was used to produce Zr-doped NMC811 (LiNi 0.8 Mn 0.094 Co 0.1 Zr 0.006 O 2 ; Zr-NMC811) precursors at mass production rates in the range 0.14 to 0.56 kg·h −1 . These precursors were then mixed with lithium hydroxide prior to heat-treatment at 800 °C for 12 h to give the corresponding Zr-NMC811 cathode material. The products were investigated using a range of analytical techniques including powder X-ray diffraction which confirmed a single phase layered α-NaFeO₂-type structure with rhombohedral R 3 ¯ m symmetry was obtained in all cases. The Zr-doped NMC811 samples underwent electrochemical investigation in half cells vs Li metal with the best sample displaying a discharge capacity of 227 mAh·g −1 at 0.05C (and 201 mAh·g −1 at 0.1C), with a capacity retention of 92.4% over 100 cycles at 1C, performing significantly better than the equivalent undoped NMC811 material that was made using a near identical method. The use of a scalable, room temperature and atmospheric pressure continuous precipitator offered a robust and flexible alternative to traditional batch stirred tank reactors and all solid-state routes, not least in terms of simplicity of process and scalability.