Electrochemical Performance of Nanorod-like (La, Zr) Co-Doped Li-rich Li_1.2Ni_0.2Mn_0.6O₂ Cathodes for Use in Lithium-Ion Batteries (Supporting Information)

A lithium-rich layered structure in lithium-ion batteries (LIBs) has attracted much affection due to its high capacity of over 250 mAh g⁻¹ after activation. This could satisfy the requirements of next-generation energy-storage devices. However, a spinel-like impurity phase that forms from the pristine layered structure during cycling is considered to be harmful to the structure stability and Li⁺ mobility, resulting in undesired electrochemical performance. In this study, nanorod-like Li_1.2Ni_0.2Mn_0.6O₂ with a three-dimensional architecture was synthesized by evaporative-crystallization with as-prepared nano-MnO₂ as a hard template. The structure stability and Li⁺ mobility of the nanorod-like Li_1.2Ni_0.2Mn_0.6O₂ was improved by the addition of an appropriate molar ratios of (La, Zr) co-dopants. This combination exhibited outstanding capacity retention of 80.9 % with a stable discharge capacity of 102 mAh g⁻¹ after 300 cycles under a high current density of 1000 mA g⁻¹ (corresponding to 5 C). This study suggests that the use of a multi-prong strategy that combines morphology control and co-doping should be an effective method for improving the high-rate performance of Li-rich materials.<br>