Particle Size and Particle-Size Distribution Effects on Li⁺ Extraction/Insertion Kinetics for Li-Rich Mn-Based Oxides

A series of Li-rich Mn-based layered material Li1.2Ni0.13Co0.13Mn0.54O2 (LMR) with different particle sizes and particle-size distributions (PSDs) have been successfully synthesized via a combustion method using different manganese sources. The particle size of the N-LMR material prepared using Mn(NO3)2·4H2O as the manganese source is the smallest, and its PSD range is the narrowest among all of the samples. The unique particle size and PSD have a great influence on the electrochemical kinetics of Li-ion extraction/insertion reactions, leading to enhanced electrochemical performance when used as a cathode material for both the half and full Li-ion cells, especially the specific charge capacity at high current rates. The value of the charge specific capacity will determine the state of charge at the initial discharge stage and then influence the discharge process of these Li-rich Mn-based oxides. The N-LMR electrode delivers an initial discharge capacity of 309.2 mA h g–1 at 0.1C, and the specific capacity can reach up to 208.1 mA h g–1 at 1C. After 140 cycles, the electrode can still maintain 95.6% of its initial specific capacity at 1C. Moreover, the material displays a superior high-temperature lithium storage property at 55 °C and the full cells using N-LMR as the cathode material also show a much better electrochemical performance.