катодные материалы

The complex oxides Li_{1 + x}Ni_{1 / 3}Co_{1 / 3}Mn_{1 / 3}O₂ were obtained by solid state method. The conclusion about influence of lithium concentration on Ni²⁺ and Ni³⁺ ions ratio in Li_{1 + x}Ni_{1 / 3}Co_{1 / 3}Mn_{1 / 3}O₂ is made. Monotonous decrease of g-factor value identified by EPR method testifies the intensification of local exchange interactions with temperature descent.

Behavior of PH/P1 lithiated iron phosphate (Phostech Lithium Inc, Canada) used as positive electrode material for Li-ion battery with LiPF₆-based electrolyte was investigated. Specific capacity of the material reached 130 mA·h/g at a rate of 0.5С and 20°C, 105 mA·h/g (1С) and 95 mA·h/g (2.1C). Cell capacity increased by 20% during first 50 cycles and minor capacity fade at a rate of 0.04% per cycle is observed after 300 cycle when cycled at 2C rate versus carbon negative electrode (CMS, PRC).

The review generalizes the literary data on physical-chemical and electrochemical properties of lithium-iron phosphate connected with perspectives of LiFePO₄ use as a cathode material for lithium-ion batteries and published up to 2009 inclusive.

The methods of increasing performances of cathode materials based on lithium-manganese spinel are discussed in this review. Next questions are examined: the reasons of LiMn₂O₄ degradation and the basic variants of problem solving including the doping of spinel matrix by metal cations; the substitution of oxygen in system Li–Mn–O by another anions; the creation of protective shell on the surface of particles; the preparation of different composites. The possibility of working substitution's spinel matrixes in 5 V domain are demonstrated.

Synthesis of electrode material based on Li₂MnSiO₄/С using widely used, environmentally safe and inexpensive Li, Si and Mn-containing precursors was considered. Mechanochemical activation was used for improving the flow of thesolid-state synthetic process and providing the necessary reactivity to obtain the target product with a high content of the main lithium-accumulating compound.Structural and morphological features of the composite were investigated by X-ray diffraction, laser diffraction granulometry.

Various strategies for the synthesis of promising electrode materials for lithium-ion battery (LIB) based on iron(II)-lithium orthosilicate (Li₂FeSiO₄) using widely distributed, environmentally friendly and inexpensive starting materials are considered. The materials obtained are multicomponent electroactive composites that include, in addition to the main lithium accumulating component, also auxiliary structure-forming and electrically conductive components based on the products of the pyrolytic decomposition of organic compounds.