Lithium manganate of core-shell structure and preparation method of lithium manganate

A technology of structural lithium manganate and lithium manganate, applied in structural parts, electrical components, battery electrodes, etc., can solve problems such as short battery cycle life, and achieve the effects of enhanced cycle stability, reduced impact, and low cost

Inactive Publication Date: 2015-01-14
ANHUI NORMAL UNIV
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

[0009] The invention provides a core-shell structure lithium manganese oxide and a preparation method thereof. The core-shell structure lithium manganese oxide separates the LiMn2O4 electrode material in the inner layer from the electrolyte, which can inhibit the reaction between the electrode and the electrolyte, and reduce the dissolution loss of manganese. Improve its electrochemical performance and high temperature performance, and solve the problem of short battery cycle life of lithium manganate battery cathode materials under high temperature, high current and other working conditions

Method used

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  • Lithium manganate of core-shell structure and preparation method of lithium manganate

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Experimental program
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Effect test

Embodiment 1

[0031] 1) The molar ratio is 4:1. Take commercial manganese carbonate and lithium carbonate, put them into a 50% acetic acid solution, emulsify with an ultrasonic emulsifier to form a homogeneous emulsion, and dry it in a dryer at 95°C;

[0032] 2) In an open high-temperature furnace, the temperature rises to 550°C at a heating rate of 5°C / min and the temperature is kept for 3h;

[0033] 3) Then use a fan to blow air into the high-temperature furnace, raise it to 700°C at a heating rate of 5°C / min, and keep it warm for 3 hours for sintering;

[0034] 4) Then gradually reduce to 550°C at a cooling rate of 5°C / min. During the cooling process, keep the fan to blow air into the high-temperature furnace;

[0035] 5) When the furnace temperature drops to 550°C, stop passing air into the high-temperature furnace. At this time, the cooling rate is no longer controlled, and it is naturally cooled to room temperature to obtain spinel-type lithium manganate material;

[0036] 6) Grind the prepared...

Embodiment 2

[0049] 1) The molar ratio is 3.8:1. Take commercial manganese carbonate and lithium carbonate, put them into an acetic acid solution with a volume concentration of 40%, emulsify with an ultrasonic emulsifier to form a homogeneous emulsion, and dry in a dryer at 95°C;

[0050] 2) In an open high-temperature furnace, the temperature is increased to 560°C at a heating rate of 5°C / min and kept for 3h;

[0051] 3) Then use a fan to blow air into the high-temperature furnace, raise it to 710°C at a temperature rise rate of 5°C / min, and keep it for 3 hours for sintering;

[0052] 4) Then gradually decrease to 560°C at a cooling rate of 5°C / min, and keep the fan to blow air into the high-temperature furnace during the cooling process;

[0053] 5) When the furnace temperature drops to 560°C, stop passing air into the high-temperature furnace. At this time, the cooling rate is no longer controlled, and it is naturally cooled to room temperature to obtain spinel-type lithium manganate material;

...

Embodiment 3

[0058] 1) The massage ratio is 4.2:1. Take commercial manganese carbonate and lithium carbonate, put them into an acetic acid solution with a volume concentration of 60%, emulsify with an ultrasonic emulsifier to form a homogeneous emulsion, and dry in a dryer at 95°C;

[0059] 2) In an open high-temperature furnace, the temperature is increased to 540°C at a heating rate of 5°C / min and kept for 3h;

[0060] 3) Then use a fan to blow air into the high-temperature furnace, raise it to 690°C at a temperature rise rate of 5°C / min, and heat it for 3 hours for sintering;

[0061] 4) Then gradually decrease to 540°C at a cooling rate of 5°C / min, and keep the fan to blow air into the high temperature furnace during the cooling process;

[0062] 5) When the furnace temperature drops to 540°C, stop passing air into the high-temperature furnace. At this time, the cooling rate is no longer controlled, and it is naturally cooled to room temperature to obtain spinel-type lithium manganate material;...

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Abstract

The invention provides lithium manganate of a core-shell structure and a preparation method of the lithium manganate. According to the lithium manganate of the core-shell structure, a LiMn2O4 electrode material on the inner layer is separated from electrolyte, reaction between the electrode and the electrolyte can be inhibited, dissolution loss of manganese is reduced, the electrochemical performance and high-temperature performance are improved, and the problem that the cycle life of the battery made of a lithium manganate battery cathode material is short under the working conditions such as high temperature and large current is solved. The lithium manganate of the core-shell structure with the advantages of small impurity phases and high specific capacity can be prepared under relatively simple conditions by using low-price raw materials, the lithium manganate of the core-shell structure is simple in process, mild in conditions, low in energy consumption, low in cost and environmentally friendly, and large-scale production is easily realized. According to the core-shell structure, the crystal form of lithium manganate is effectively protected, and dissolution of bivalent manganese is relieved. Moreover, according to the super-capacitor performance of Co3O4, impact of large current on lithium manganate can be alleviated, and the fall time of lithium manganate is prolonged, so that the cycling stability of the battery is enhanced. When the temperature rises, the performance of the material is strengthened.

Description

Technical field [0001] The invention relates to a core-shell structure lithium manganate and a preparation method thereof. Background technique [0002] Lithium-ion battery is a secondary battery with high energy density, high power density and long life span, which plays an important role in modern society. In various mobile devices, electric vehicles, and power tools, the role of lithium-ion batteries is almost irreplaceable. Cathode material is one of the decisive factors for the performance and cost of lithium-ion batteries, and is an important direction for the improvement of lithium-ion batteries. At present, the active cathode material used in lithium-ion batteries is mainly lithium cobalt oxide. However, due to the lack of cobalt resources, high prices, and poor safety performance, it is not conducive to the promotion and application of lithium-ion batteries; lithium iron phosphate has many advantages due to its expected advantages. Ion batteries have also been widely t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/505
CPCH01M4/505Y02E60/10
Inventor 陶海升党建成王斌涂丹丹
Owner ANHUI NORMAL UNIV
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