Influence of preparation method on structure, morphology, and electrochemical performance of spherical Li[Ni0.5Mn0.3Co0.2]O2

Abstract

Spherical Li[Ni 0.5 Mn 0.3 Co 0.2 ]O 2 was prepared by both the continuous hydroxide co-precipitation method and continuous carbonate co-precipitation method under different calcined temperatures. The physical properties and electrochemical behaviors of Li[Ni 0.5 Mn 0.3 Co 0.2 ]O 2 prepared by two methods were characterized by X-ray diffraction, scanning electron microscope, and electrochemical measurements. It has been found that different preparation methods will result in the differences in the morphology (shape, particle size, and tap density), structure stability, and the electrochemical characteristics (shape of initial charge/discharge curve, cycle stability, and rate capability) of the final product Li [Ni 0.5 Mn 0.3 Co 0.2 ]O 2 . The physical and electrochemical properties of the spherical Li[Ni 0.5 Mn 0.3 Co 0.2 ]O 2 prepared by continuous hydroxide co-precipitation is apparently superior to the one prepared by continuous carbonate co-precipitation method. The optimal sample prepared by continuous hydroxide co-precipitation at 820°C exhibits a hexagonally ordered layer structure, high special discharge capacity, good capacity retention, and excellent rate capability. It delivers high initial discharge capacity of 175.2 mAh g −1 at 0.2 C rate between 3.0 and 4.3 V, and the capacity retention of 98.8 % can be maintained after 50 cycles. While the voltage range is broadened up to 2.5 and 4.6 V vs. Li + /Li, the special discharge capacities at 0.2 C, 0.5 C, 1 C, 2 C, 5 C, and 10 C rates are as high as 214. 3, 205.0, 198.3, 183.3, 160.1 and 135.2 mAh g −1 , respectively.

The effects of LiTi2(PO4)3modification on the performance of spherical Li1.5Ni0.25Mn0.75O2+δcathode material

“…All the diffraction peaks can be well indexed based on the O3 type layered structure of a hexagonal NaFeO 2 with space group R 3m. 36,37 No signicant lattice parameter differences were observed between the pristine and LTP-coated material. However, there still appear some additional weak diffraction peaks between 20 and 25 , indicating a layered structure with Li 2 MnO 3 character (space group C2/m) and the ordering of Li, Ni, and Mn atoms in the transition metal layers.…”

Ammonia-free coprecipitation synthesis of a Ni–Co–Mn hydroxide precursor for high-performance battery cathode materials

“…This demonstrates a similar cycling performance upon charging to 4.3 V to that of the cathodes that were synthesized using the precursor produced via ammonia-containing coprecipitation. 13,[42][43][44][45] The high-voltage cycling ability of cathode in the voltage region of 3.0-4.6 V was analysed in the electrolyte with 5 wt% FEMC as a high-voltage additive at the rates of 0.1C, 0.2C and 0.1C again for possible high-energy density battery applications. As displayed in Fig.…”

“…Widely used coprecipitation synthesis of metal hydroxides includes the use of ammonia as a chelating agent 4,5,[7][8][9][10][11][12][13][14] forming transition metal-ammonia complexes and it proceeds in two steps: first, metal ions form a complex with ammonia aqueous solution, in which more than 0.2 M of ammonia water is used, as represented in eqn (1). Then, by anion exchange from ammonia to hydroxide anions that come from NaOH added, metal hydroxides precipitate slowly as in eqn (2).…”

Hierarchical LiNi0.8Co0.15Al0.05O2 plates with exposed {010} active planes as a high performance cathode material for Li-ion batteries

“…Because of its high capacity, low toxicity and low cost, over the past twenty years, LiNiO 2 has been considered as an alternative cathode material to commercialized LiCoO 2 . [1][2][3][4][5] Nevertheless, pristine LiNiO 2 demonstrates poor thermodynamic stability, a property which hinders its commercialization. Through various research efforts, it was found that Co and Al co-doping can greatly improve its thermodynamic stability and electrochemical reactivity.…”