Improved particle hardness of Ti-doped LiNi_1/3Co_1/3Mn_1/3-xTi_xO₂ as high-voltage cathode material for lithium-ion batteries

Titanium doping on LiNi_1/3Co_1/3Mn_1/3O₂ cathode material is performed in a bid to improve its electrochemical and thermal properties at high voltage. The particle hardness is measured in order to verify the structural stability, and is found to improve from 104 to 143 MPa as a result of the Ti doping. Thus, high electrode density is obtained with less cracked particles in the electrode. Electrode density of 3.9 g cm⁻³ is employed in order to confirm the effect of particle hardness on the electrochemical performance. The cycle performance is evaluated at 4.5 V and high temperature of 60 °C, and the obtained capacity retention after 50 cycles is found to be significantly improved via Ti doping. The cycled electrodes show that the generation of crack inside particles are suppressed for Ti-doped LiNi_1/3Co_1/3Mn_1/3O₂. The thermal stability of the charged electrode is also improved via Ti doping, because of the enhanced structural stability. On the basis of these results, Ti is considered to be a viable dopant for improving particle hardness, which is an important factor as regards improving the electrochemical and thermal properties of LiNi_1/3Co_1/3Mn_1/3O₂.