Positive electrode material of high-capacity dynamic-type nickel-rich lithium ion battery and preparation method thereof

Abstract

The invention relates to a positive electrode material of a high-capacity dynamic-type nickel-rich lithium ion battery and a preparation method. The molecular formula of the positive electrode material of the high-capacity dynamic-type nickel-rich lithium ion battery is LiaNi1-x(MM')xO2.M''O, wherein a is equal to 0.9-1.2, x is more than or equal to 0 and less than or equal to 0.7, and M is at least one of Co, Mn and Al; M' is at least one of Co, Al, V, Mn, Zr, Mg, Ti, Cr, Zr, La, Ce, Pr, Nd, Nb, Mo, Y, Sr, Ba, B, Sr, Sn and Ta; M''O is a cladding layer, and M'' is Co and Al. The invention also relates to a preparation method for the positive electrode material of the high-capacity dynamic-type nickel-rich lithium ion battery. The material machining performance is excellent, the battery prepared by utilizing the material, the cycling performance and the high-voltage performance are excellent, the safety and stability in use can be realized, not only can the application performance requirement of a portable electronic device on the battery be met, but also the positive electrode material is applicable to the power battery.

Description

technical field [0001] The invention relates to a lithium-ion battery cathode material and a preparation method thereof, in particular to a high-capacity power type nickel-rich lithium-ion battery cathode material and a preparation method thereof. Background technique [0002] In the 21st century, traditional energy sources such as coal and oil are gradually exhausted, and efficient, environmentally friendly, and renewable secondary energy sources have become the focus of attention. As a representative of new energy, lithium-ion batteries have been widely used in electronic products, portable computers, power tools, energy storage backup power, transportation and other fields, playing a pivotal role and playing an irreplaceable role. [0003] With the rapid development of science and technology, people have higher and higher requirements for lithium-ion batteries. Portability, high energy density, safety and non-toxicity are the main directions for the development of new ene...

AI Technical Summary

Problems solved by technology

[0008] Li a Ni 1-x m x o 2 It is a lithium-oxygen compound based on Ni, which has a layered crystal structure, high capacity, and relatively low cost, but the material has poor thermal stability, high surface alkalinity, easy water absorption, easy gas production, and poor processability , the crystal structure is unstable during charge and discharge, the electrochemical performance is easy to deteriorate and there are safety hazards

When charging, the Li in the material + out, the Ni in the lattice 2+ is oxidized to Ni 3+ and Ni 4+ ions, and high-valence Ni ions are prone to side reactions with the electrolyte and dissolve. On the one hand, it will affect the electrical properties of the material, and on the other hand, it is easy to generate gas and release heat, causing safety problems; when discharging, Li + Embedded in the lattice, the high-valent Ni ions inside the material are reduced to Ni 2+ , while Ni 2+ with Li + The ionic radius is relatively close, and it is easy to produce Ni 2+ Occupy the original Li + position resulting in Li + Situations where it cannot be embedded, resulting in capacity fading and reduced efficiency

[0009] At present, the synthesized layered nickel-rich cathode materials (LiNi 1-x m x o 2 ) The main defects are: 1. The surface alkalinity of the material is high, the processing performance is not good, and the battery production environment is high, which is easy to cause the pole piece to drop, the battery absorbs water and bulges; 2. The compatibility between the material and the electrolyte is relatively low. Poor, prone to side reactions, leading to material performance degradation; 3. The material has poor structural stability, poor high-temperature performance, and safety performance such as overcharging and hot box are restricted; 4. The energy density of the material under conventional voltage cannot meet The demand for power batteries needs to increase the upper limit of charging voltage, improve the voltage platform and energy density

[0010] Based on the above defects, the commercial application of layered nickel-rich cathode materials is limited, especially in power batteries, which cannot be used on a large scale.

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