Unlocking the superior performance of Ni-rich layered materials through precise precursor engineering

Abstract

In this study, we investigated the influence of precursor engineering on the performances of Ni-rich cathode for LIBs. By systematically varying the NH₄OH to metal ratio during co-precipitation process, we controlled the porosity of precursors, affecting the microstructure of the calcined materials. SEM, BET, and true density analyses revealed that lower NH₄OH/Me ratios produce more porous precursors, which enhance Li-source diffusion and promote uniform sintering. XRD and residual lithium analyses confirmed reduced primary particle and lower residual lithium in the calcined materials, leading to improved rate capability and cyclability. Specifically, cathodes derived from low-density precursors showed a 30 % increase in discharge capacity at 3 C and fewer internal cracks after 50 cycles compared to high-density samples. Mechanical tests indicated that high-density materials exhibited a 250 % increase in fracture toughness. These findings highlight the crucial role of precursor design in optimizing Ni-rich cathodes and offer a straightforward strategy for assessing precursor quality.