Three-dimensional porous lithium manganate thin film electrode, preparation method and application thereof

Abstract

The invention discloses a three-dimensional porous lithium manganate film electrode, a preparing method of the three-dimensional porous lithium manganate film electrode and the application of the three-dimensional porous lithium manganate film electrode as the positive pole of a lithium ion battery. The preparing method includes the steps that a high-molecular polymer porous film with a hydrophilic surface is obtained through pretreatment; the chemical bath deposition method is used for depositing manganese oxide to the surface of the high-molecular polymer porous film with the hydrophilic surface so as to obtain a precursor film containing manganese; the precursor film containing manganese is soaked into a solution containing lithium, and the mixed solution reacts in the protective atmosphere for 0.5-8 h at the temperature of 250 DEG C-400 DEG C and then reacts in the air atmosphere for 1-10 h at the temperature of 500 DEG C-900 DEG C to obtain the three-dimensional porous lithium manganate film electrode finally. The three-dimensional porous lithium manganate film electrode is an overall electrode, does not need addition of an adhesion agent or a conductive agent, has excellent rate performance and cycling stability and can be widely applied to the fields of high-performance lithium ion batteries and the like as the positive pole of the lithium ion battery.

Description

technical field [0001] The invention relates to the field of positive electrodes of lithium ion batteries, in particular to a three-dimensional porous lithium manganate thin film electrode, a preparation method thereof and an application as a positive electrode of lithium ion batteries. Background technique [0002] LiMn 2 o 4 It has good structural stability, strong safety performance, and high theoretical capacity (148mAh / g) and discharge voltage (4.15V). In addition, manganese resources are abundant, cheap, non-toxic and harmless, therefore, LiMn 2 o 4 It has great potential and attractiveness as a cathode material. However, there are three problems in practical application of such materials. First, LiMn 2 o 4 Intercalation / deintercalation of lithium ions in the 3.3-4.3V voltage range will lead to LiMn 2 o 4 The asymmetric and severe expansion / contraction of the crystal structure (ie, the Jahn-Teller effect) results in a severe decrease in cycle life. Second, du...

AI Technical Summary

Problems solved by technology

First, LiMn 2 o 4 Intercalation / deintercalation of lithium ions in the 3.3-4.3V voltage range will lead to LiMn 2 o 4 Asymmetric and violent expansion / contraction of the crystal structure (i.e. the Jahn-Teller effect), resulting in a severe decrease in cycle life

Second, due to the Mn 3+ There is a disproportionation reaction that generates Mn 2+ ions and dissolve into the electrolyte, so LiMn 2 o 4 The crystal structure will be irreversibly damaged, resulting in a large loss of capacity

Third, under high temperature conditions and overcharge conditions, the electrolyte will be oxidized and decomposed, which will affect the LiMn 2 o 4 Electrochemical performance and safety

[0004] Although current information about LiMn 2 o 4 Some progress has been made in the preparation of materials, but the preparation of high-quality LiMn 2 o 4 The materials are all powder materials, and the process is complicated and the cost is high, which is not conducive to industrial production and electrode preparation

In addition, there are no reports at home and abroad on the method and process of one-step synthesis of three-dimensional porous lithium manganese oxide thin film electrodes.

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