Preparation methods of spherical lithium manganate for lithium-ion power battery and precursor of spherical lithium manganate

Abstract

The invention discloses preparation methods of a spherical lithium manganate for a lithium-ion power battery and a precursor of the spherical lithium manganate. The preparation method for the precursor is carried out as the following steps: (1) preparing a manganese salt water solution; (2) preparing a precipitant water solution; (3) injecting the prepared solutions in the step (1) and the step (2) to a reaction kettle with a stirrer and a constant-temperature water bath; (4) mixing the obtained MnCO3 and a compound containing an element M based on a mol ratio of M to Mn described in the invention, sintering and obtaining the precursor. The preparation method of the spherical lithium manganate is carried out as the following steps: mixing the precursor and Li2CO3, sintering and obtaining an M-doped spherical spinel lithium manganate. Compared with the prior art, the method of the invention has the advantages that: (1) impurity content is low, discharge plateau is high, specific capacity is high, cycle performance is good, high-temperature performance is good and tap density is high; and (2) raw material price and production cost are low, powder particle size can be controlled, microscale additive disperses uniformly, particle size distribution is concentrate, and microscopic morphology is spherical or spheroidic.

Description

technical field [0001] The invention relates to a method for synthesizing a positive electrode material of a lithium-ion secondary battery, in particular to a method for preparing spherical lithium manganate for a lithium-ion power battery. Background technique [0002] In 1978, Armand proposed that both the positive and negative electrodes use TiS which can allow lithium ions to be intercalated and extracted. 2 Concentration battery is formed. During the charging and discharging process of this kind of battery, lithium ions are intercalated and extracted between the two electrodes, which is vividly called a "rocking chair" lithium-ion secondary battery. However, the battery voltage is only 0~2V, which does not have the high voltage characteristics of lithium batteries. In early 1980, LiCoO was discovered 2 with TiS 2 The same layered structure, in the same year, Oxford University Goodendugh et al. proposed to use LiCoO 2 , LiNiO 2 , LiMn 2 o 4 As the positive el...

AI Technical Summary

Problems solved by technology

But directly react with manganese oxalate and lithium carbonate or lithium hydroxide, need certain O in the reaction process 2 partial pressure and generate large amounts of CO 2 Gas, which may cause the material to lack oxygen and have too many voids, thereby destroying the physical and chemical properties of the material and causing fluctuations in the performance of the material. In addition, complexing agents need to be added during the reaction process, which increases the cost and difficulty of process control.