Industrialization of tailoring spherical cathode material towards high-capacity, cycling-stable and superior low temperature performance for lithium-ion batteries

Abstract

Three different types of spherical cathodes (Li[Ni_0.6Co_0.2Mn_0.2]O₂) were synthesized via hydroxide co-precipitation method coupled with high temperature lithiation process. The particle size, nanostructure, specific surface area and pore distributions can be controlled as expected. X-ray diffraction patterns revealed that the as-obtained cathode materials had a typical hexagonal α-NaFeO₂ layered structure with a space group Rm. The electrochemical measurements demonstrate that Li[Ni_0.6Co_0.2Mn_0.2]O₂ with 3 μm-size in diameter exhibited higher initial coulombic efficiency (94.9%), rate capacity (156 mA h g⁻¹ at 900 mA g⁻¹), and low-temperature property (157 mA h g⁻¹ at 180 mA g⁻¹, 0 °C) in comparison with the larger one (12 μm). Most impressively, an ultra-stable capacity of 156 mA h g⁻¹ can be retained at 180 mA g⁻¹ even after 300 cycles at 0 °C. As is known, Li[Ni_0.6Co_0.2Mn_0.2]O₂ with 3 μm-size has the best result among the reported Li[Ni_0.6Co_0.2Mn_0.2]O₂-based cathode materials. The excellent electrochemical performance of the smaller size cathode results from the advantageous hierarchical nanorods architecture, porous characteristics, and reduced ions/electrons transport path.