Method for producing positive electrode material for secondary battery

A secondary battery and manufacturing method technology, applied in the direction of secondary batteries, battery electrodes, circuits, etc., can solve the problem of difficulty in controlling the crystallinity, particle size and particle size distribution of products, not necessarily suitable as positive electrode materials, and deterioration of charge and discharge characteristics, etc. problems, to achieve excellent charge and discharge characteristics, high occlusion and release efficiency, and improved stability

Inactive Publication Date: 2010-02-03
TOKYO INST OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] However, lithium transition metal silicates with a molar ratio of transition metal to silicic acid of about 1:1 are generally synthesized by high-temperature sintering of inorganic compounds such as inorganic lithium salts, transition metal salts, and silicon dioxide as raw materials. The crystallinity, particle size, and particle size distribution of the product are controlled. Therefore, its performance is not necessarily suitable as a positive electrode material compared with conventional lithium transition metal oxides.
That is, these materials basically have the following problems: the capacity for reversibly occluding and releasing lithium ions is low, and the charge-discharge characteristics deteriorate as the charge-discharge operation is repeated.

Method used

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  • Method for producing positive electrode material for secondary battery
  • Method for producing positive electrode material for secondary battery
  • Method for producing positive electrode material for secondary battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

In addition to changing the silicon source to phenyl silicone (C 6 h 5 SiO 1.5 ) n Except, the rest were carried out under the same conditions as in Comparative Example 1. 2 FeSiO 4 Synthesis.

[0083] X-ray diffraction experiment

X-ray diffraction experiments were performed on the samples obtained in Comparative Example 1 and Example 1, respectively. Specifically, using CoKα rays monochromatized by a color filter, the tube voltage and tube current were set to 35kV and 40mA, respectively, and the measurement angle was set to 15°figure 1 , the X-ray diffraction pattern of Example 1 is shown in figure 2 .

[0084] From figure 1 and figure 2 It can be seen that in Comparative Example 1, when operating at a temperature below 650°C, there are many impurities remaining, and no single-phase Li 2 FeSiO 4 , compared with this, in Example 1, the single-phase Li 2 FeSiO 4 . Thus, by using (C 6 h 5 SiO 1.5 ) n As a raw material, the synthesis temperature can be lowered...

Embodiment 2

In addition to changing the lithium source to Li2 CO 3 , Change the silicon source to phenyl silicone resin (C 6 h 5 SiO 1.5 ) n Except, the rest were carried out under the same conditions as in Comparative Example 2. 2 MnSiO 4 Synthesis.

[0094] X-ray diffraction experiment

X-ray diffraction experiments were performed on the samples obtained in Comparative Example 2 and Example 2, respectively. Specifically, using CuKα rays monochromated by a color filter, the tube voltage and tube current were set to 50kV and 180mA, respectively, and the measurement angle was set to 15° Figure 5 . Figure 5 (a) in represents comparative example 2, Figure 5 (b) in (b) shows Example 2.

[0095] In Comparative Example 2, when operating at a temperature below 750°C, many impurities remained, and no single-phase Li 2 FeSiO 4 , by contrast, in Example 2, operating at 600 °C, an essentially single-phase Li 2 FeSiO 4 . Thus, by using (C 6 h 5 SiO 1.5 ) n As a raw material, the sy...

Embodiment 3

In addition to changing the silicon source to phenyl silicone (C 6 h 5 SiO 1.5 ) n The rest were synthesized under the same conditions as in Comparative Example 3.

[0105] X-ray diffraction experiment

X-ray diffraction experiments were performed on the samples obtained in Comparative Example 3 and Example 3, respectively. Specifically, using CuKα rays monochromated by a color filter, the tube voltage and tube current were set to 35kV and 40mA, respectively, and the measurement angle was set to 15° Figure 8 and Figure 9 . Figure 8 represents Comparative Example 3, Figure 9 Example 3 is shown.

[0106] In Comparative Example 3, operating at a temperature below 800°C, many impurities remained, and no single-phase Li 2 CoSiO 4 , by contrast, in Example 3, operating at 700 °C, an essentially single-phase Li 2 CoSiO 4 . Thus, by using (C 6 h 5 SiO 1.5 ) n As a raw material, the synthesis temperature can be lowered by about 100°C.

[0107] Electron microscope obs...

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Abstract

Disclosed is a positive electrode material for secondary batteries, which is characterized by being composed of a lithium transition metal silicate obtained by firing a mixture of a transition metal compound containing at least one transition metal selected from the group consisting of Mn, Fe, Co and Ni, a lithium compound and a silicon polymer compound. The lithium transition metal silicate can be produced at low cost, while having high lithium absorption/desorption efficiency per unit amount of the transition metal, high stability and high safety. Consequently, the lithium transition metal silicate enables to obtain a secondary battery having excellent charge/discharge characteristics.

Description

technical field [0001] This application claims priority based on Japanese Patent Application No. 2007-82102 filed in Japan on March 27, 2007 and Japanese Patent Application No. 2007-315091 filed in Japan on December 5, 2007, and the contents thereof are incorporated into this application. [0002] The present invention relates to a method for producing a positive electrode material capable of reversibly occluding and releasing lithium ions, and the utilization of the positive electrode material in a secondary battery. Background technique [0003] As secondary batteries, lead secondary batteries, nickel-cadmium secondary batteries, nickel-metal hydride batteries, etc. have been used in the past, but in recent years, the performance of electronic equipment such as mobile phones, cameras, and notebook computers has been astonishing. There is also an increasing demand for high performance secondary batteries used as power supplies for equipment. [0004] The lithium ion second...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/52H01M4/50H01M10/40
CPCY02E60/12Y02E60/10
Inventor 山田淳夫早濑章吾藤田善岐西村真一立川守日野贤一
Owner TOKYO INST OF TECH
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