Composition-Tailored Synthesis of Gradient Transition Metal Precursor Particles for Lithium-Ion Battery Cathode Materials

Abstract

We report the tailored synthesis of particles with internal gradients in transition metal composition aided by the use of a general process model. Tailored synthesis of transition metal particles was achieved using a coprecipitation reaction with tunable control over the process conditions. Gradients in the internal composition of the particles was monitored and confirmed experimentally by analysis of particles collected during regularly timed intervals. Particles collected from the reactor at the end of the process were used as the precursor material for the solid-state synthesis of Li1.2(Mn0.62Ni0.38)0.8O2, which was electrochemically evaluated as the active cathode material in a lithium battery. The Li1.2(Mn0.62Ni0.38)0.8O2 material was the first example of a structurally integrated multiphase material with a tailored internal gradient in relative transition metal composition as the active cathode material in a lithium-ion battery. We believe our general synthesis strategy may be applied to produce a variety of new cathode materials with tunable interior, surface, and overall relative transition metal compositions.