Chemical modification of nickel-rich layered cathode materials to improve battery life

Abstract

Mechanical integrity issues of Ni-rich cathode materials are major bottlenecks for their commercial application, stemming from the abrupt anisotropic lattice contraction during H2 ↔ H3 phase transitions. Herein, zirconium is used to modify LiNi0.9Co0.05Mn0.05O2 to solve the mechanical integrity issues. The relationship between the mechanical integrity issues and electrochemical performance is systematically examined to gain insights into the Zr activity-governing mechanisms. Results find that the addition of zirconium not only improves the diffusion ability of lithium ions by providing a rapid channel for diffusion of lithium ions, but also enhances mechanical properties by inhibiting cation mixing. As a result, the optimal LiNi0.9Co0.05Mn0.05O2 achieves superiority capacity retention of 84.12 % after 200 cycles at 5C, higher than that of unmodified LiNi0.9Co0.05Mn0.05O2 74.32 %. This work deeply investigates the information on the bulk structure and interaction mechanism between substitution cations and Ni-rich layered oxides, which provides a new insight to design and construct of advanced high-capacity cathode materials.