Polymorph positive electrode material for lithium ion battery and preparation method of material

A technology for lithium ion batteries and cathode materials, which is applied in battery electrodes, secondary batteries, circuits, etc., can solve the problems of cycle performance decline, cannot effectively solve the irreversible changes of lithium cobalt oxide, etc., and achieve the effect of improving the surface structure.

Active Publication Date: 2013-08-14
DONGGUAN AMPEREX TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when the degree of Li removal exceeds 70%, the hexagonal lattice deformation reaches a certain level and begins to produce a monoclinic phase (P3). The monoclinic phase is in a metastable state and will automatically transform into an irreversible O1 structure. Therefore, when lithium cobaltate Take off Li + When it exceeds 70%, its cycle performance drops sharply
At present, the application of lithium cobalt oxide is developing towards high voltage, 4.45V (vs.Li + / Li) lithium cobalt oxide has begun to be commercialized, but it still cannot meet the demand, so it is necessary to develop lithium cobalt oxide for applications above 4.5V as soon as possible
[0006] From the above analysis, it can be seen that the traditional bulk doping and surface coating methods cannot effectively solve the problem of irreversible structural changes of lithium cobalt oxide above 4.5V, because neither bulk phase doping nor surface coating Changing the structure of lithium cobalt oxide is only adding supports on the basis of the original structure of lithium cobalt oxide, and does not produce qualitative changes. Therefore, in order to fundamentally solve the problem of irreversible phase transition above 4.5V, it is necessary to change lithium cobalt oxide. structure, so that in Li + Does not pass through or produce P3 phase in the process of deintercalation

Method used

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  • Polymorph positive electrode material for lithium ion battery and preparation method of material
  • Polymorph positive electrode material for lithium ion battery and preparation method of material
  • Polymorph positive electrode material for lithium ion battery and preparation method of material

Examples

Experimental program
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Effect test

Embodiment 1

[0035] Dissolve manganese nitrate in water, add ammonium citrate, and stir evenly to form a solution with a Mn concentration of 1mol / L, wherein the molar ratio Mn:NH 4 + =1:1; Dissolve cobalt acetate in water to form a 1mol / L solution; configure 1mol / L LiOH and ammonia solution; make the above three solutions according to the molar ratio of Mn:Co:Li of 0.3:0.7:1 at the same time Spray into the atomization chamber, the dewdrops formed by atomization are in the range of 10-500nm, and heated and dried at 200°C to obtain LiCo 0.7 mn 0.3 (OH) 3 Precursor, sintered at 500°C to obtain LiCo 0.7 mn 0.3 o 2 .

[0036] Table 1 is LiCo 0.7 mn 0.3 o 2 with LiCoO 2 The comparison of the gram capacity under different magnifications can be seen from Table 1, because Mn replaces part of Co, LiCo 0.7 mn 0.3 o 2 Compared with LiCoO at 0.2C gram capacity 2 low, but when the discharge rate increases to 2C, LiCo 0.7 mn 0.3 o 2 The gram-to-capacity ratio of LiCoO 2 The gram capacit...

Embodiment 2

[0043] Dissolve manganese acetate and nickel nitrate in water at a molar ratio of Mn:Ni of 1:2, add diammonium edetate, and stir evenly to form a solution with a Mn concentration of 1mol / L, wherein the molar ratio Mn:Ni:NH 4 + =1:2:3; Dissolve cobalt nitrate in water to form a 1mol / L solution; configure 1mol / L LiOH and ammonia solution; make the above three solutions according to the molar ratio of Mn:Ni:Co:Li is 0.1:0.2 : 0.7: 1 and sprayed into the atomization chamber at a uniform speed at the same time. 0.7 mn 0.1 Ni 0.2 (OH) 3 precursor, and then sintered at 1100 °C to obtain LiCo 0.7 mn 0.1 Ni 0.2 o 2 .

[0044] Figure 4 Is LiCo 0.7 mn 0.1 Ni 0.2 o 2 with LiCoO 2 At 25 ℃, 3.0 ~ 4.6V, 0.5C / 0.5C charge and discharge cycle curve, it can be seen from the figure that LiCo 0.7 mn 0.1 Ni 0.2 o 2 It has ideal cycle performance.

Embodiment 3

[0046] Dissolve manganese nitrate and nickel acetate in water at a molar ratio of Mn:Ni=1:1, add ammonium citrate, and stir evenly to form a solution with a Mn concentration of 1mol / L, wherein the molar ratio Mn:Ni:NH 4 + =1:1:2; Dissolve cobalt nitrate in water to form a 1mol / L solution; configure 1mol / L LiOH and ammonia solution; make the above three solutions according to the molar ratio of Mn:Ni:Co:Li is 0.05:0.05 : 0.9: 1 and sprayed into the atomization chamber at a uniform speed at the same time, the dewdrops formed by atomization are in the range of 10-500nm, and heated and dried at 200°C to obtain LiCo 0.9 mn 0.05 Ni 0.05 (OH) 3 Precursor; sintered at 900°C to obtain LiCo with layered structure and spinel structure 0.9 mn 0.05 Ni 0.05 o 2 ; the LiCo 0.9 mn 0.05 Ni 0.05 o 2 with Al(OH) 3 According to the molar ratio Li:Al=1:0.02, mix evenly, and sinter at 600°C for 2h to obtain LiCo coated with Al. 0.88 mn 0.05 Ni 0.05 al 0.02 o 2 .

[0047] LiCo 0.8...

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Abstract

The invention discloses a polymorph positive electrode material with a crystal lattice structure consisting of a layered hexagonal crystal lattice and a spinel-shaped cubic crystal lattice for a lithium ion battery. The structural formula of the polymorph positive electrode is LiCo<1-x-y-z>MnxNiyAlzO2, wherein x is more than zero and less than or equal to 0.3, y is more than or equal to 0 and less than or equal to 0.2, and Z is more than or equal to zero and less than or equal to 0.02. Compared with a single layered structure positive electrode material, the polymorph positive electrode material for the lithium ion battery has excellent structural stability and thermal stability and remarkable cycling property, thermal safety and multiplying property. In addition, the invention also discloses a preparation method of the polymorph positive electrode material for the lithium ion battery.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries. More specifically, the invention relates to a polycrystalline positive electrode material for lithium ion batteries and a preparation method thereof. Background technique [0002] Lithium-ion batteries have been widely used in various consumer electronics and mobile devices, and are currently the type of batteries with the highest energy density that can be commercialized. However, mobile devices have never-ending demand for energy and power. The energy density of current lithium-ion batteries is far from meeting the needs of smartphones and electric vehicles. Therefore, it is necessary to optimize materials and structural design to further increase energy density. [0003] For lithium-ion batteries, the energy density of the positive electrode material has a great influence on the energy density of the battery. Therefore, the improvement of the energy density of the positive electr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/505H01M4/525H01M10/0525
CPCY02E60/122Y02E60/10
Inventor 徐磊敏
Owner DONGGUAN AMPEREX TECH
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