Lithium ion battery cathode material and preparation method thereof

Abstract

The invention discloses a lithium ion battery cathode material. The cathode material is provided with the chemical formula of Li2TiSiO5, takes the Alpha-VPO5 structure, and adopts the three-dimensional space layered structure. According to the cathode material, under the room temperature condition, the galvanostatic charge-discharge test is carried out in the current density of 10 mA / g within the range of 0.01-2.0 V, so that the reversible capacity obtained during the charge-discharge process is greater than 180 mAh / g, for voltage, the platform of the lithium removing process is 0.68-0.75 V, and the platform of the lithium inserting process is 0.28-0.35 V. When a titanium lithium silicate material is used as the cathode of the lithium ion battery, the problem of cathode lithium precipitation caused by polarization can be effectively avoided, and the safety performance of the lithium ion battery can be greatly improved; compared with the lithium ion battery using lithium titanate as the cathode, the lithium ion battery using titanium lithium silicate is wider in charge-discharge voltage range, high in capacity and excellent in battery cycle performance, and the energy density of the lithium ion battery is greatly improved; the prepared cathode material has a smoother charge-discharge platform.

Description

technical field [0001] The invention relates to the field of lithium-ion battery materials, in particular to a preparation method for using novel lithium titanium silicate as a lithium-ion battery negative electrode material. Background technique [0002] Lithium-ion batteries are secondary batteries. Due to their advantages of high power density, high energy density, excellent cycle performance and wide temperature range, they have been widely used in electronic products, communication equipment, electric vehicles, weapons and aerospace, etc. field. The rapid development of various fields has further put forward higher requirements for the performance of lithium-ion batteries. Existing cathode materials for lithium-ion batteries include layered LiMO 2 , LiM with spinel structure 2 o 4 and LiMPO with olivine structure 4 (M = transition metal ions such as Co, Ni, Mn, and V) and high-capacity materials represented by layered ternary materials and lithium-rich manganese ba...

AI Technical Summary

Problems solved by technology

However, the discharge platform of titanate is as high as 1.55V, which reduces the working voltage platform of lithium-ion batteries and limits its application.

Transition metal oxides can obtain considerable reversible capacity as anode materials for lithium-ion batteries, but their cycle performance is poor, and the mechanism of reactive lithium storage needs further study.

Patoux and Masquelier studied the performance of Li2TiSiO5 with α-VPO5 structure as an electrode for Li-ion batteries, (cf.: Sebastien Patoux and Christian Masquelier. Lithium Insertion into Titanium Phosphates, Silicates, and Sulfates. Chem Mater. 2002, 14, 5057 5068,) they found that the material does not have lithium ion insertion and intercalation properties, and is not suitable for lithium ion battery electrodes

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