Morphology-controlled carbon quantum dot/nickel cobaltate composite electrode material and preparation method

A carbon quantum dot and composite electrode technology, applied in the field of nanomaterials, can solve the problems of limited effect, expensive composite raw materials, and limited sources, and achieve the effects of simple preparation method, improved rate performance, and improved cycle performance.

Active Publication Date: 2016-08-31
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Taking a single nickel cobalt oxide as the positive electrode material as an example, when the potassium hydroxide aqueous solution is used as the electrolyte, when the current density changes from 1A / g to 30A / g, the retention rate of its capacitance value is generally around 25% to 45%. About 5,000 cycles of attenuation can reach more than 5%. Composite polymer materials (such as polypyrrole), graphene materials and carbon nanotube materials can improve the deficiency of nickel cobalt oxide materials to a certain extent, but the effect is limited. , and the compound has disadvantages such as expensive raw materials and not widely sourced

Method used

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  • Morphology-controlled carbon quantum dot/nickel cobaltate composite electrode material and preparation method
  • Morphology-controlled carbon quantum dot/nickel cobaltate composite electrode material and preparation method
  • Morphology-controlled carbon quantum dot/nickel cobaltate composite electrode material and preparation method

Examples

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Effect test

Embodiment 1

[0030] (1) Preparation of carbon quantum dots with ethylenediamine and citric acid as raw materials

[0031] 0.1g of citric acid, 300μL of ethylenediamine and 500μL of water were added to a 50mL polytetrafluoroethylene-lined reactor, and reacted at 140°C for 4 hours. After cooling to room temperature, distilled water was added to form an aqueous solution of carbon quantum dots. Add ethanol to the aqueous solution for sedimentation to obtain a flocculent solid, collect the solid precipitate, rinse with ethanol for 2-3 times, put it into a vacuum oven at 40°C for drying, and obtain a tan powder.

[0032] (2) Preparation of carbon quantum dots / nickel cobalt oxide composites

[0033] 1 mmol nickel nitrate hexahydrate (analytical pure), 2 mmol cobalt nitrate hexahydrate (analytical pure) and various amounts of the above carbon amounts

[0034] Subdot powder (W= 10, 20 and 40 mg) was dissolved in 20ml of water and 20ml of ethanol to form a pink clear mixture, then added 12 mmol of ...

Embodiment 2

[0036] (1) Preparation of carbon quantum dots using p-phenylenediamine as raw material

[0037] First measure 5ml of ethanol and put it into a 50ml centrifuge tube, then weigh 0.2g of urea (analytical pure) and 0.2g of untreated

[0038] Oxidized p-phenylenediamine (analytical pure) was quickly added into the centrifuge tube and shaken until completely dissolved to form a reddish-brown solution. Then add 45ml of deionized water, mix well, transfer the mixture to a high-pressure reactor (150 ml), and keep it sealed. First preheat the high-temperature oven to 160°C, then put the reaction kettle into the oven to react for 10 hours, after the reaction is completed, cool down to room temperature naturally. The obtained solution was settled and purified with dilute ammonia water to obtain a pure carbon quantum dot solution, and then vacuum-dried at 40° C. to obtain dark brown carbon quantum dot powder.

[0039] (2) Preparation of carbon quantum dots / nickel cobalt oxide composites ...

Embodiment 3

[0042] (1) Preparation of carbon quantum dots from polyvinylpyrrolidone

[0043] First put 1g of polyvinylpyrrolidone (K-30, analytically pure) into the quartz boat of the tube furnace, and then set the temperature at

[0044] It rises from room temperature to 400°C within 100 minutes, calcines the sample for 3 hours, and naturally drops to room temperature after the reaction. The whole process is completed by exposing to air. Subsequently, the bulk sample obtained for the first time was ground into powder, and then 30 mL of ethanol was added for ultrasonic precipitation. After that, the ethanol liquid was taken for centrifugal purification (15,000 r / min), distillation and other treatments, and finally the carbon dot solid powder was obtained.

[0045] (2) Preparation of carbon quantum dots / nickel cobalt oxide composites

[0046] 0.8 mmol nickel nitrate hexahydrate (analytical pure), 1.6 mmol cobalt nitrate hexahydrate (analytical pure) and different amounts of the above car...

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Abstract

The invention belongs to the technical field of nanometer materials, and particularly relates to a morphology-controlled carbon quantum dot / nickel cobaltate composite electrode material and a preparation method. The preparation method specifically comprises the following steps of (1) dissolving carbon quantum dot powder, nickel nitrate hexahydrate, cobalt nitrate hexahydrate and urea into a mixed solvent of water and ethanol, mixing, putting into a polytetrafluoroethylene-lined reaction kettle, adding foam nickel, sealing, heating to react, cooling, taking out foam nickel, flushing and drying; (2) performing heat treatment on the dried foam nickel, so as to obtain the carbon quantum dot / nickel cobaltate composite electrode material using the foam nickel as a substrate. The preparation method has the advantages that by adjusting the feeding amount of carbon quantum dots, different morphologies of the composite material, such as urchin shape, corolla shape and waxberry shape are formed on the micro structure; the preparation method is simple, the implementing is easy, and the cost is low; the chemical and physical property of obtained material is stable, and the application prospect is good in the fields of electrochemical energy storage and catalyzing.

Description

technical field [0001] The invention belongs to the technical field of nanometer materials, and in particular relates to a carbon quantum dot / nickel cobaltate composite electrode material with controllable morphology and a preparation method. Background technique [0002] Carbon quantum dots, also known as carbon dots or carbon nanodots, are a new type of carbon nanomaterials with a size below 10 nanometers. As a zero-dimensional nanomaterial, it has gradually attracted the attention of academia and even industry because of its excellent solvent dispersibility, good electrical conductivity, low toxicity, wide range of sources and low price. So far, the applications of carbon quantum dots are mostly limited to biomarkers, sensor devices, display devices and other fields. In contrast, the research in the field of electrochemical energy storage is still in its infancy, and it did not start to emerge until 2013. Recent research work has shown that carbon quantum dots can effec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/583H01M4/62H01M4/525B82Y30/00B82Y40/00
CPCB82Y30/00B82Y40/00H01M4/362H01M4/525H01M4/583H01M4/625Y02E60/10
Inventor 魏济时熊焕明
Owner FUDAN UNIV
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