Lithium ion secondary battery and preparation method thereof

A secondary battery and lithium-ion technology, applied in the field of lithium-ion secondary batteries and its preparation, can solve the problems of poor electronic conductivity, insufficient high-power discharge performance of batteries, etc., and the method is simple and easy, easy to scale production, Effect of high capacity and cycle performance

Active Publication Date: 2012-07-11
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the poor electronic conductivity of the electrode material in the existing lithium-ion secondary battery, which causes insufficient high-power discharge performance of the battery, and provides a method for preparing a lithium-ion secondary battery. The prepared electrode material in the lithium-ion secondary battery has improved electronic conductivity and high-power discharge performance

Method used

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Examples

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Effect test

preparation example Construction

[0014] The invention provides a method for preparing a lithium ion secondary battery. The method comprises accommodating a battery pole core in a battery casing, injecting a non-aqueous electrolytic solution into the battery casing, and then injecting the non-aqueous electrolytic solution The battery casing is sealed after charging and forming, wherein the non-aqueous electrolyte contains additives, and the additive is one or more of aniline monomers and pyrrole monomers, and the charging and forming includes one or more Constant current charging, the charging current of at least one of the constant current charging is 0.001-0.05C, and the cut-off voltage formed by the charging is 3.6-4.2V.

[0015] According to the method of the present invention, the nonaqueous electrolytic solution contains additives, and the additives are monomers capable of oxidative coupling reactions under electrochemical conditions to form conductive polymers, for example: the additives can be aniline m...

Embodiment 1

[0051] This example is used to illustrate the lithium ion secondary battery and its preparation method according to the present invention.

[0052] (1) Preparation of positive electrode

[0053] 9g of PVDF binder was added to 170mL of N-methylpyrrolidone (NMP), and after it was completely dissolved, 6g of carbon black Super P conductive agent (commercially purchased from Shanghai Huipu Industrial Chemicals Co., Ltd.) was added and dispersed evenly, and then 150 g of carbon-coated LiFePO 4 (Carbon content: 2.32% by weight, commercially purchased from Tianjin Yushun Technology Co., Ltd.) powder was slowly added to the above mixed solution, stirred and dispersed at high speed for 2 hours to prepare positive electrode slurry. Spread the dressing on both sides on aluminum foil with a thickness of 16 microns and spread evenly. Dry at 140°C, roll, roll and cut into positive electrode pieces, the size of the electrode piece is 471cm (length) × 44cm (width) × 0.0138cm (thickness), th...

Embodiment 2

[0074] This example is used to illustrate the lithium ion secondary battery and its preparation method according to the present invention.

[0075] The lithium-ion secondary battery was prepared in the same manner as in Example 1, except that the formation conditions were as follows: at 25°C, charge to 3.6V with a constant current of 11mA (that is, a current of 0.02C), and then continue to charge at 44mA The current intensity (that is, the current is 0.01C) charging, cut-off voltage 3.98V, constant voltage charging for 2 hours, sealed, made the lithium ion battery C2 with a nominal capacity of 550 mA.

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Abstract

The invention provides a preparation method of a lithium ion secondary battery. The method comprises the following steps of: accommodating a battery pole in a battery shell; injecting non-aqueous electrolyte into the battery shell; and performing charging formation and then sealing the battery shell in which the non-aqueous electrolyte is injected, wherein the non-aqueous electrolyte contains one or more additives; the one or more additives are one or more of aniline monomers and pyrrole monomers; the charging formation comprises one or more constant current charging processes; at least one charging current in the constant current charging is 0.001-0.05 C; and the cut-off voltage of the charging formation is 3.6-4.2 V. The invention also provides the lithium ion secondary battery prepared by the method provided by the invention. The lithium ion secondary battery prepared by the method provided by the invention has superior high-power discharge performance. The method according to the invention is simple and practical and is easy for realizing large-scale production.

Description

technical field [0001] The invention relates to a lithium ion secondary battery and a preparation method thereof. Background technique [0002] Lithium-ion secondary batteries have the characteristics of high voltage, no memory effect, high energy density and good cycle performance, so they are widely used. [0003] In general, the performance of a battery depends on the electrode material. At present, the positive electrode materials of lithium-ion secondary batteries with practical application value are mainly various transition metal oxides. Lithium-ion batteries have poor high-power discharge capabilities. From the perspective of the preparation method of lithium-ion secondary battery electrodes: due to the poor electronic conductivity of intercalated electrode materials, in order to obtain relatively ideal electrical properties, it is generally necessary to add a certain amount of conductive agent (for example: carbon black, graphite, etc.) when preparing electrodes. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M10/058H01M10/0567H01M10/0525
CPCY02E60/122Y02E60/10Y02P70/50
Inventor 程耀波江文锋
Owner BYD CO LTD
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