Properties of LiNi0.8Co0.1Mn0.1O2 as a high energy cathode material for lithium-ion batteries

Abstract

Nickel-rich layered materials are prospective cathode materials for use in lithium-ion batteries due to their higher capacity and lower cost relative to LiCoO 2 . In this work, spherical Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursors are successfully synthesized through a co-precipitation method. The synthetic conditions of the precursors -including the pH, stirring speed, molar ratio of NH 4 OH to transition metals and reaction temperature -are investigated in detail, and their variations have significant effects on the morphology, microstructure and tap-density of the prepared Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursors. LiNi 0.8 Co 0.1 Mn 0.1 O 2 is then prepared from these precursors through a reaction with 5% excess LiOH· H 2 O at various temperatures. The crystal structure, morphology and electrochemical properties of the Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursors and LiNi 0.8 Co 0.1 Mn 0.1 O 2 were investigated. In the voltage range from 3.0 to 4.3 V, LiNi 0.8 Co 0.1 Mn 0.1 O 2 exhibits an initial discharge capacity of 193.0 mAh g −1 at a 0.1 C-rate. The cathode delivers an initial capacity of 170.4 mAh g −1 at a 1 C-rate, and it retains 90.4% of its capacity after 100 cycles.

Rationally‐Directed Synthesis and Characterization of Nickel‐Rich Cathode Material for Lithium Ion Battery

“…The ratio in the XRD pattern is ca . 1.31, which implies the cation disorder between Li + and Ni 2+ is above average level as compared with reports ,,,. The element molar ratio of Li : Ni : Co : Mn in the cathode material is 1.00 : 0.800 : 0.100 : 0.0980 as detected by ICP‐AES, close to the expected ratio of 1.0 : 0.8 : 0.1 : 0.1, which, combined with the XRD pattern, identifies the lithiated derivative as the designed LiNi 0.8 Co 0.1 Mn 0.1 O 2 (denoted as LNCM).…”

“…However, the co‐precipitation synthesis of Ni‐rich hydroxides of Ni 1‐x Co x Mn y (OH) 2 has been proven difficult due to strict control of reaction conditions(pH, concentration of ammonia solution, reaction time, etc.) and deficient theoretical guidelines ,. At present, some reaction conditions for Ni‐rich hydroxide co‐precipitation, usually optimized in onerously empirical ways, remain diverse or even unknown in previous reports ,,,.…”

“…and deficient theoretical guidelines ,. At present, some reaction conditions for Ni‐rich hydroxide co‐precipitation, usually optimized in onerously empirical ways, remain diverse or even unknown in previous reports ,,,. Analysis of thermodynamic equilibrium is sometimes applied to assist in determining the optimized reaction condition, which however used to being limited to the discussion of single variable ,.…”

“…Secondly, there exists the phase transition of polymorphs of hydroxide such as α‐Ni(OH) 2 and β‐Ni(OH) 2 that can co‐exist in the whole co‐precipitation process, bringing about impure final products . Thirdly, the Mn(OH) 2 in solution is metastable and can be oxidized to manganese oxides when exposed in air at elevated temperature above 60 °C ,. Therefore, a protective atmosphere is usually exerted through continuous flow of inert gas, which tends to incur more or less the evaporation of ammonia gas.…”

Effect of Metal (Mn, Ti) Doping on NCA Cathode Materials for Lithium Ion Batteries

“…Among these materials, LiNiO 2 is of low cost, has a large theoretical capacity (275 mAh g −1 ), and is more environmentally friendly than LiCoO 2 [5][6][7][8]. However, several limitations such as a difficult synthesis protocol for stoichiometric LiNiO 2 , partially reversible phase for LiNiO 2 , and Li/Ni cation mixing have to be overcome before LiNiO 2 can be commercially used as a cathode material for LIBs.…”