Method for producing lithium ion cells positive electrode material and equipment thereof

Abstract

The preparation process of positive pole material for lithium ion cell includes the following steps: setting the mixture of hydroxide, oxide or salt of lithium and hydroxide, oxide or salt of transition metal in certain ratio in crucible; setting the crucible in microwave oven to calcine the mixture; setting the crucible in electric furnace to sinter the calcined matter; cooling the crucible with sintered matter in cooling cavity; crushing and sieving the sintered matter to obtain the positive pole material product for lithium ion cell. The apparatus for preparing positive pole material for lithium ion cell, combined microwave-electric heating furnace, is also disclosed. The present invention is suitable for continuous large-scale production of positive pole material for lithium ion cell.

Description

Technical field [0001] The invention relates to a preparation method of the positive electrode material of the lithium ion battery, and also relates to equipment used in the preparation method of the positive material of the lithium ion battery. Background technique [0002] At present, the synthesis methods of lithium-ion battery cathode materials such as lithium cobaltate, lithium manganate, lithium nickelate, lithium ferrous phosphate, lithium vanadate, etc. mainly include high-temperature solid-phase synthesis, microwave sintering, co-precipitation, sol-gel Glue method, Pechini method, etc. Among them, soft chemical methods such as co-precipitation method, sol-gel method, and Pechini method are complex and difficult to achieve industrialization. At present, the conventional synthesis methods mainly use high-temperature solid-phase synthesis. [0003] The high-temperature solid-phase synthesis method is to mix lithium salts and other metal salts uniformly in a certain pr...

AI Technical Summary

Problems solved by technology

However, the disadvantages of the high-temperature solid-phase synthesis method are: high synthesis temperature, long sintering time, high energy consumption, low production efficiency, high material preparation or production costs; a large amount of lithium salts volatilize during the production process, and an excessive amount needs to be added during the reaction process Therefore, it is difficult to control the formula; due to the slow heating rate, the grain coarsening is easily caused by the surface diffusion at the low temperature stage, the product particle size is large and the particle size range is wide, and the particle shape is irregular. The morphology characteristics of the material are relatively difficult, resulting in the electrochemical performance of the material is not easy to control

[0016] However, the method of preparing lithium-ion battery cathode materials by microwave sintering has not yet been popularized and achieved large-scale industrialization, mainly because the method also has the following disadvantages:

This non-uniform heating phenomenon will cause poor consistency in the performance indicators of the synthesized lithium-ion battery cathode materials.

At present, it is still difficult to solve the non-uniform heating problem unique to the microwave sintering method.

[0018] (2) The insulation problem of microwave heating has always been a difficult problem

But this will increase the complexity of the equipment structure, increase the difficulty and cost of equipment manufacturing

[0019] (3) Accurate measurement and control of temperature is difficult

Microwave heating is not heated from the outside to the inside like traditional electric furnace heating, but overall heating, and usually due to the difficulty of heat preservation, the surface temperature of the heated material is lower than the internal temperature, and usually only the measured temperature can be measured in large-scale continuous production. Heating the temperature of the surface of the material or the environment near the surface will cause inaccurate temperature measurement, which in turn will lead to inaccurate temperature control

[0020] (4) Low sintering output

The main reason is that continuous mass production cannot be realized

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