Dual cationic modified high Ni-low co layered oxide cathode with a heteroepitaxial interface for high energy-density lithium-ion batteries

Lithium-ion batteries (LIBs) with high energy density, safety with longer service life, cost-effectiveness, and superior cycling stability is a demand to achieve the driving range of 300 miles per charge in electric vehicles (EVs). High Ni-low Co cathodes are among the high potential cathodes for next-generation lithium-ion batteries. Despite its numerous advantages, it still hinders from poor cycling stability and structural degradation, mainly affecting its commercialization. Herein, a facile high-temperature solid-state method is employed to synthesize dual cation doped NCM (LiNi0.94Co0.03Mn0.03O2) by concurrent substitution of Zirconium and Gallium. It has been found that Ga doping can promote cation order, strengthen the TM-O bond energy, diminish oxygen loss, thus stabilize the reversible anionic redox processes. Meanwhile, the strong Zr-O bond intensifies TM-O slabs, facilitating Li+ intercalation/de-intercalation. As a result, Zr-Ga dual-doped (NCMZG) develops a heteroepitaxial interface, which significantly reduces cation mixing, suppresses layered to spinel/rock-salt phase transition and alleviates cyclability as well as voltage decay. Hence, NCMZG exhibits outstanding capacity retention of 91.9% at 0.5C after 100 cycles, while NCM can only maintain 72.64% of initial discharge capacity. Additionally, NCMZG possesses superior rate capability even at an ultrahigh C-rate of 10C as compared to NCM. Hence, the dualdoping phenomenon is beneficial to enhance the electrochemical performance of high Ni-low Co layered oxide cathodes.

Automated summary

The study demonstrates that dual cation doping with Zirconium and Gallium significantly enhances the electrochemical performance of high Ni-low Co cathodes, leading to better cyclability and capacity retention for NCMZG compared to traditional NCM.