Bergmeal-based lithium sulphur battery cathode material as well as preparation and application methods thereof

A lithium-sulfur battery and cathode material technology, which is applied in battery electrodes, lithium storage batteries, and positive electrodes, etc., can solve problems such as capacity decay, poor sulfur conductivity, battery negative electrode corrosion, and battery internal resistance.

Inactive Publication Date: 2014-04-16
XIANGTAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] Nevertheless, lithium-sulfur batteries still have the following three problems: (1) Lithium polysulfide produced during charging and discharging of lithium-sulfur batteries is easily soluble in organic electrolyte, which gradually reduces the active material of the electrode, and due to the shuttle principle, the dissolved Lithium polysulfide will pass through the separator and reach the lithium sheet of the negative electrode of the battery. The resulting lithium sulfide and other products have poor conductivity and are insoluble, which will cause corrosion of the negative electrode of the battery and increase the internal resistance of the battery, resulting in poor cycle performance of the battery and gradual increase in capacity. attenuation
(2) The conductivity of sulfur is poor, which is not conducive to the high rate performance of the battery. It is impossible to charge and discharge the Li / S battery with 100% sulfur as the positive electrode at room temperature. This is because the ionic conductivity and electronic conductivity of sulfur are very low. It leads to poor electrochemical performance and low utilization rate of sulfur in the electrode. Generally, compounding sulfur with carbon or other conductive materials can solve the problem of poor conductivity.
(3) During the charging and discharging process of sulfur, the expansion and shrinkage of the volume is very large, which may cause battery damage, because during the cycle, the volume deformation of the sulfur electrode in the lithium-sulfur battery is as high as 22%, which may cause microcracks inside the sulfur electrode
The existence of such microcracks and the insulating phase Li 2 The generation of S at the cracks destroys the integrity of the electrode, which eventually aggravates the capacity fading of lithium-sulfur batteries

Method used

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  • Bergmeal-based lithium sulphur battery cathode material as well as preparation and application methods thereof
  • Bergmeal-based lithium sulphur battery cathode material as well as preparation and application methods thereof
  • Bergmeal-based lithium sulphur battery cathode material as well as preparation and application methods thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Pretreatment of diatomite powder: select diatomite powder with a particle size of less than 5 μm, wash it with deionized water, then ultrasonically vibrate the cleaned diatomite for 1 hour, and then dry it in an oven at 85° C. for 24 hours. Add diatomaceous earth to 10mol / L HCl solution for pickling treatment for 2 hours, then pre-activate, keep diatomaceous earth powder at 100°C for 2 hours under vacuum conditions, and cool to room temperature under vacuum conditions to obtain purified diatomite Soil powder material.

[0039] Mix the above-mentioned pretreated diatomite powder material with elemental sulfur 1:1 evenly, place it in a quartz boat, heat it to 100°C at 2°C / min under a vacuum of 100Pa, keep the temperature for 2h, and continue to mix The sample was heated to 120°C at a heating rate of 2°C / min, kept at a constant temperature for 0.5h, kept under vacuum and then lowered to room temperature at a cooling rate of 2°C / min. The samples were further ground and dri...

Embodiment 2

[0041] The diatomite sulfur-carrying material obtained in Example 1 is selected to prepare the nickel-coated diatomite sulfur-carrying material: the diatomite sulfur-carrying material is pretreated to ensure that the coated metal is evenly coated and has a good Adhesion.

[0042] 1. Degreasing: Take 5g of diatomaceous earth sulfur-loaded material in 200ml of ethanol solution, add 100ml of 37% HCl, ultrasonically oscillate for 20min at a temperature of 30°C, wash with deionized water until the pH is neutral, and filter to dry.

[0043] 2. Sensitization: the above-mentioned diatomaceous earth sulfur-loaded material in 10g / L SnCl 2 2H 2 Carry out sensitization treatment in O+40g / L HCL solution for 30min, wash with deionized water, and filter dry.

[0044] 3. Activation: Put the sensitized diatomite sulfur-loaded material in 0.5g / L PdCl 2 +0.25mL HCl solution for activation treatment for 30min, washed with deionized water, and filtered dry.

[0045] 4. Reduction: Soak the acti...

Embodiment 3

[0055] The technological process of pretreatment diatomite powder is identical with embodiment 1.

[0056] Mix the pretreated diatomite material with elemental sulfur 1:1 evenly, place it in a quartz boat, heat it to 155°C in a tube furnace fed with Ar gas, keep the temperature constant for 12h, and continue to heat the mixed sample to 320°C, Constant temperature 6h, maintain the protective atmosphere conditions and cool to room temperature. The samples were further ground and dried to prepare sulfur-loaded materials on diatomaceous earth.

[0057] Preparation of copper-coated diatomaceous earth sulfur-loading material: except that the following solution composition and process are used for reduction and electroless plating, it is prepared through the same steps as in Example 2.

[0058] Reduction: soak the activated diatomite sulfur-loaded material in 10% formaldehyde solution for 0.5-2min, wash with deionized water, and filter to dry.

[0059] Electroless copper cladding: ...

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Abstract

The invention discloses a bergmeal-based lithium sulphur battery cathode material as well as preparation and application methods thereof. The cathode material uses bergmeal as the skeleton, and elemental sulfur is injected into the bergmeal, so as to obtain sulfur-bearing composite material, and then the sulfur-bearing composite material is coated with a conductive material. By adopting the bergmeal, the dissolution of polysulfide can be reduced and the volume expansion of sulphur during charge-discharge process is restrained, and the cycling performance of lithium sulphur batteries is improved. Conductive material is used for coating, so that the electrical conductivity of material is improved and the capacity of the lithium sulphur batteries is increased. The lithium sulphur battery cathode material is simple in preparation technology, and the bergmeal belongs to natural environmentally-friendly material, and is low in cost and benificla to the industrialization of the lithium sulphur batteries. Meanwhile, the introduction of the bergmeal also promotes the industrial transformation and upgrading of the nonmetallic minerals.

Description

technical field [0001] The invention belongs to the field of new energy materials, and in particular relates to a diatomite mineral-based lithium-sulfur battery cathode material and a preparation and application method thereof. Background technique [0002] With the increasingly serious environmental pollution and the continuous aggravation of the energy crisis, the development of high energy density, low-cost renewable energy systems has gradually become the focus of people's research. Elemental sulfur is considered to be an excellent cathode material for lithium batteries due to its high specific capacity, low price, environmental friendliness, and light density. Lithium-sulfur batteries use elemental sulfur as the positive electrode reaction material and metal lithium as the negative electrode, and the theoretical energy density can reach 2600Wh / kg. Compared with conventional lithium-ion batteries, lithium-sulfur batteries are able to achieve 3 to 5 times their energy de...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/136H01M4/36H01M4/1397
CPCY02E60/122H01M4/136H01M4/1397H01M4/362H01M4/624H01M10/052H01M2004/028Y02E60/10
Inventor 谢淑红潘俊安潘勇雷维新欧云徐海平刘丽媚伍成
Owner XIANGTAN UNIV
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