Improved Electrochemical Properties of LiCoO₂ via Ni, Mn Co-doping from LiNi_0.8Co_0.1Mn_0.1O₂ for Rechargeable Lithium-ion Batteries

Abstract

composite was prepared by the combination of mechanical ball milling and heat treatment. The as-prepared LiCoO 2 /LiNi 0.8 Co 0.1 Mn 0.1 O 2 composite was characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray Spectroscopy. The LiCoO 2 /LiNi 0.8 Co 0.1 Mn 0.1 O 2 composite was utilized as cathode material for lithium-ion batteries. Compared with the milled LiCoO 2 /LiNi 0.8 Co 0.1 Mn 0.1 O 2 composite, the LiCoO 2 /LiNi 0.8 Co 0.1 Mn 0.1 O 2 composite after heat treatment exhibited superior performance, including in an increased coulombic efficiency, better capacity retention and enhanced rate capability. The present work demonstrated that Ni and Mn from LiNi 0.8 Co 0.1 Mn 0.1 O 2 were co-doped for the LiCoO 2 during high temperature, resulting in improving the electrochemical properties of the LiCoO 2 /LiNi 0.8 Co 0.1 Mn 0.1 O 2 composite.

Convenient Surface Treatment of LiNi0.8Co0.1Mn0.1O2 Materials Improve the Cycle Performance

“…The performance of the initial charge-discharge is related to the surface structure of the material. [29][30][31] Thus, this shows that the Rocksalt phase contributes to the cycle of the materials.…”

Inhibition of Adverse Phase Transition at 4.2 V via increasing Cobalt Content on Ni-Rich Layered Cathode Materials

“…But interestingly, NCM-Co16 with the highest Co content at a high cutoff voltage (4.6 V) had the best output capacity during discharge and the highest initial Coulomb efficiency. The performance improvement in initial charge–discharge was related to the modification of the surface structure; ,, hence, it was indicated that the increase of Co content was able to improve the surface structural stability of high-nickel layered materials under a high voltage. This corresponds to the morphological changes in Figure .…”

“…Thereinto, Mn 4+ exists to compensate for Ni 2+ and make the comprehensive valence state of transition-metal ions to +3, thus stabilizing the layered structure . The redox of Ni ions vs Ni 2+ /Ni 4+ shows their capacity; hence, increasing the content of Ni is the most effective way to improve the energy density of ternary cathode materials. − However, blindly reducing the Co content and increasing the Ni content to reduce the cost and increase the capacity will make the lattice structure of the material extremely unstable.…”

A Cobalt Enrichment Strategy for Suppressing the 4.2 V Adverse Phase Transition in Ni-Rich Layered Materials

“…[8][9][10][11] The shortcomings of NCM811 have been addressed by a number of novel modifications. [12][13][14][15][16][17][18][19] However, blind modification with an insufficient understanding of the defects is of no value to the improvement of the cycling performance of NCM811.…”