Evolution of a Radially Aligned Microstructure in Boron-Doped Li[Ni0.95Co0.04Al0.01]O2 Cathode Particles

do not randomly occupy the Ni and Li layers; instead, these ions occupy their sites in an ordered pattern, forming a superlattice. The superlattice gradually disappears as the lithiation temperature is increased. One peculiar structural feature observed during lithiation is the prevalence of twin defects that preexist in the hydroxide precursor as growth twins. The twin defects, which could serve as nucleation sites for intraparticle cracks, also gradually anneal out during lithiation. TEM analysis substantiates the importance of the hydroxide precursor microstructure in a coprecipitation process and provides a basis for choosing the appropriate lithiation temperature and soaking time to obtain the desired cathode structure and primary particle morphology.