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

• DOI: 10.1021/acsami.2c02204
• Publication Date: 2022-04-11T20:45:13Z
• Authors: Ye Sung Kim; Ju Hwan Kim; Yang-Kook Sun; Chong S. Yoon
• Keywords: 01 natural sciences; 0104 chemical sciences

Boron (B) (1.5 mol %) is introduced into Li[Ni0.95Co0.04Al0.01]O2 (NCA95) to create a radially oriented microstructure with strong crystallographic texture. The cathode allows dissipation of the abrupt lattice strain near charge end and improves cycling stability NCA95 (88% capacity retention after 100 cycles at 0.5 C). Transmission electron microscopy (TEM) analysis B-doped during lithiation reveals that highly provided by hydroxide precursor. prevents random agglomeration primary particles keeps them elongated through (003) faceting. selected-area diffraction shows structure lithiated oxide undergoes subtle structural changes even crystal fully converted from P3̅m1 R3̅m 600 °C. Li+/Ni2+ intermixing prevalent due slow oxidation Ni2+ Ni3+. Li+ do not randomly occupy Ni Li layers; instead, these ions their sites in an ordered pattern, forming superlattice. superlattice gradually disappears as temperature increased. One peculiar feature observed prevalence twin defects preexist precursor growth twins. defects, which could serve nucleation for intraparticle cracks, also anneal out lithiation. TEM substantiates importance coprecipitation process provides basis choosing appropriate soaking time obtain desired particle morphology.