Minimizing the Cobalt Content in LiNi0.8Mn0.1Co0.1O2 Cathode Material without Altering the Energetic Performances

To reduce the cost and enhance the energy density of lithium-ion batteries (LIBs), enabling electric vehicles (EVs) to achieve long ranges and compete cost-effectively with vehicles with internal combustion engines, developing nickel-rich/cobalt-poor layered cathode (LiNi1-x-yMnyCoxO2, x+y ≤ 0.2) is one of the most current effective strategies. In fact, to increase the capacity (> 200 mAh.g-1) a high Ni content is required while to impact the battery cost a low Co content is favorable. Hence, the development of new compositions for the positive electrode with less cobalt content becomes essential to provide alternative options. This study is a follow of our previous investigation of low cobalt NMC cathode material, a systematic approach was adopted to synthesized two Ni-rich/Co-poor cathode materials, namely LiNi0.8Mn0.19Co0.01O2 (NMC-1%) and LiNi0.8Mn0.17Co0.03O2 (NMC-3%) via the co-precipitation route, utilizing a continuous stirred tank reactor. The structure, morphology, and electrochemical properties at 0.1C, 0.2 C, and 0.5 C current rate, of NMC-1% and NMC-3% cathodes were investigated and compared. Furthermore, to assess the structural evolution throughout the deintercalation/intercalation of Li+ ions in both materials, operando diffraction of synchrotron radiations was employed as powerful tool for understanding the first lithiation/ de-lithiation mechanism. Both NMC-1% and NMC-3% cathodes demonstrate distinct electrochemical performances. At 0.1 C, their initial specific discharge capacities are 178 mAh.g-1 and 180 mAh.g-1, respectively; at 0.2 C, 169 mAh.g-1 and 171 mAh.g-1; and at 0.5 C, 138 mAh.g-1 and 156 mAh.g-1. When compared with NMC-10% from our previous study, NMC-1% achieves comparable capacity retention at these rates, highlighting its performance consistency. Moreover, both materials exhibit distinct mechanisms upon the delithiation/lithiation process.