Electrolysis Process-Facilitated Engineering of Primary Particles of Cobalt-Free LiNiO2 for Improved Electrochemical Performance

Theparticle morphology of LiNiO2 (LNO), the final productof Co-free high-Ni layered oxide cathode materials, must be engineeredto prevent the degradation of electrochemical performance caused bythe H2-H3 phase transition. Introducing a small amount of dopantoxides (Nb2O5 as an example) during the electrolysissynthesis of the Ni(OH)(2) precursor facilitates the engineeringof the primary particles of LNO, which is quick, simple, and inexpensive.In addition to the low concentration of Nb that entered the latticestructure, a combination of advanced characterizations indicates thatthe obtained LNO cathode material contains a high concentration ofNb in the primary particle boundaries in the form of lithium niobiumoxide. This electrolysis method facilitated LNO (EMF-LNO) engineeringsuccessfully, reducing primary particle size and increasing particlepacking density. Therefore, the EMF-LNO cathode material with engineeredmorphology exhibited increased mechanical strength and electricalcontact, blocked electrolyte penetration during cycling, and reducedthe H2-H3 phase transition effects.