Surface modified positive pole material of lithium ion cell and preparation method thereof

A technology for lithium ion batteries and positive electrode materials, which is applied in the field of the preparation of positive electrode materials, can solve the problems of increased cost and process complexity, unfavorable large-scale production, unfeasible industrialization, etc., and achieves easy industrial production, low cost, and good cycle. performance effect

Inactive Publication Date: 2006-02-08
ZHEJIANG UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

It has been reported that the surface coating of layered or spinel cathode systems with oxides such as alumina, zinc oxide, lithium cobaltate, and silica can effectively improve the LiMn 2 o 4 Normal and high temperature cycle performance and LiCoO 2 Anti-overcharge ability, but all adopt the sol-gel method, the process is relatively complicated, and it is not feasible in industry
[0004] In order to improve cycle performance and high-temperature performance, Chinese patent CN 200310112600.9 adopts a coating method in which the additive and the positive electrode material are uniformly mixed in water and an organic solvent, and then the solvent is evaporated to decompose the additive into an oxide after heat treatment, but this method involves When it comes to solid-liquid mixing, stirring and solvent evaporation, it increases the cost and complexity of the process, which is very unfavorable for large-scale production

Method used

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  • Surface modified positive pole material of lithium ion cell and preparation method thereof
  • Surface modified positive pole material of lithium ion cell and preparation method thereof
  • Surface modified positive pole material of lithium ion cell and preparation method thereof

Examples

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preparation example Construction

[0028] The preparation method of described lithium ion battery cathode material, comprises the following steps:

[0029] (1) uniformly mixing the additive and the positive active material to obtain a uniform mixture of the positive active material and the additive;

[0030] (2) compressing the mixture of the positive electrode active material and the additive obtained in (1) into a block under a pressure of 3 to 20 MPa;

[0031] (3) The mixture of positive electrode active material and additives compressed into blocks in (2) is first heated to temperature 1, temperature 1 is 50°C to 400°C, and the reaction time is 0.1 to 8.0 hours; then raised to temperature 2, The temperature 2 is 200° C. to 900° C., and the reaction time is 0.1 to 8.0 hours; thereby obtaining the positive electrode material of the lithium ion battery.

[0032]The added element in the additive may be 0.1-15% by weight of the positive electrode active material.

[0033] The principle of the surface coating m...

Embodiment 1

[0036] Preparation of a surface-coated modified lithium-ion battery positive electrode material: Li / Mn molar ratio 1:0.9~1.1 2 CO 3 and electrolytic MnO 2 After uniform mixing in a ball mill, heat treatment at 750°C for 20 hours to obtain lithium manganate LiMn with an average particle size of 10-15 μm 2 o 4 1. Mix aluminum nitrate and lithium manganate with the weight of aluminum accounting for 1.5% of lithium manganate, and then press them into blocks under a pressure of 10 MPa. Then, the positive electrode material of the present invention was obtained after treatment at 120° C. and 500° C. for 2 h, respectively.

[0037] The obtained surface-coated modified LiMn was measured 2 o 4 Its XRD spectrum is shown in figure 1 , compared with the standard card, it is a spinel structure with intact crystal form, and no other diffraction peaks are observed.

[0038] The obtained surface-coated modified LiMn was measured 2 o 4 Its TEM photo. It can be seen from the figure th...

Embodiment 2

[0043] Preparation of a surface-coated modified lithium-ion battery cathode material: the same as in Example 1 except that the additive was changed from aluminum nitrate to zinc nitrate.

[0044] Example 2 has an initial discharge capacity of 120mA h / g at room temperature, and after 50 cycles at a rate of 0.5C, the capacity retention rate is 97.5%. The initial discharge capacity at 55°C was 115mA h / g, and there was no decay after 45 charge-discharge cycles, and the capacity increased to 116mA h / g.

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Abstract

The invention relates to a lithium battery anode material and method for making same. The said anode comprises base material and surface modification layer or surface coating layer or both of them. The inventive method comprises steps of mixing metal nitrate or other low melting point molten salt with anode material base material; rising temperature 1 to melting the salt and forming perfect lubrication and coating on the surface of base particles; decomposing the salts into oxide in temperature 2 and coating on the base material surface, diffusing into the internal part of particles to form surface modification layer. The invention has the advantages of protecting anode material resolving and phase-change in electrolytic solution.

Description

technical field [0001] The invention relates to a lithium ion battery, more specifically to a preparation method and modification of positive electrode materials used in polymer lithium ion batteries and lithium ion secondary batteries. Background technique [0002] Lithium-ion battery is a new type of green high-energy rechargeable battery that appeared in the early 1990s, and has become the focus of research and development all over the world. Layered and spinel-type lithium transition metal oxides are considered as preferred cathode materials for high-energy-density lithium-ion batteries. [0003] The positive electrode material is an important part of the lithium-ion battery. During the charging and discharging process of the lithium-ion battery, it is not only necessary to provide the lithium required for the reciprocal intercalation / extraction in the positive and negative lithium intercalation compounds, but also to bear the burden of forming SEI on the surface of the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/58H01M4/48H01M4/04C01D15/00C01G1/02C01G45/00C01G51/00C01G53/00H01M4/62
CPCY02E60/12Y02E60/10
Inventor 赵新兵涂健曹高劭朱铁军涂江平
Owner ZHEJIANG UNIV
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