High-Performance 3D Pinecone-Like LiNi1/3Co1/3Mn1/3O2 Cathode for Lithium-Ion Batteries

A high-performance LiNi1/3Co1/3Mn1/3O2 cathode with a uniform pinecone-like morphology is reported, which is prepared by a solvothermal process, using urea to tune the pH of a mixed solvent of ethylene glycol and water, and a subsequent calcination process. The material has uniform, well-defined pinecone-like particles with lengths of 3-4 mu m and widths of 1-2 mu m. It exhibits a significantly enhanced cathodic performance in a Li-ion battery, with a reversible discharging capacity of up to 199 mAh g(-1) when it is charged to 4.6 V at a charge/discharge rate of 0.2 C and of 159.2 mAh g(-1) at a rate of 2 C. After 100 charge/discharge cycles, the capacity retention is 91%, demonstrating its superior capacity and stability in comparison with a sample prepared via the coprecipitation method. The cyclic voltammetry and electrochemical impendence spectroscopy results reveal that the pinecone-like LiNi1/3Co1/3Mn1/3O2 material has markedly lower polarization and lower resistance to the migration of lithium ions than the coprecipitation sample. The material's high performance, especially its outstanding capacity at a high discharge rate and its significantly enhanced cyclability, makes the synthesized pinecone-like LiNi1/3Co1/3Mn1/3O2 a promising high-performance cathode material for lithium-ion batteries.